Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: aging; microRNA; sarcopenia; cytokine
Online: 20 August 2020 (07:39:53 CEST)
Age-related sarcopenia meaningfully increases the risks of functional limitations and mortality in the elderly. Although circulating microRNAs (c-miRNAs) are associated with aging-related cellular senescence and inflammation, the relationships between c-miRNAs and sarcopenia in the elderly remain unclear. This study investigates whether circulating myo-miRNAs and inflammation-related miRNAs are associated with sarcopenia in the elderly. This study recruited 77 eligible subjects (41 males and 36 females) from 597 community-dwelling older adults, and then divided into normal (n=24), dynapenic (loss of muscular function without mass, n=35), and sarcopenic groups (loss of muscular function with mass, n=18). Moreover, myo-miRNAs (c-miRNA-133a and c-miRNA-486), inflammation-related miRNAs (c-miRNA-21 and c-miRNA-146a), and inflammatory-related cytokine levels in plasma were determined using quantitative polymerase chain reaction and ELISA, respectively. The results demonstrated that sarcopenic group exhibited lesser skeletal muscle mass index (SMI), handgrip strength, and gait speed, as well as, lower c-miR-486 and c-miR-146a levels, compared to those of normal and dynapenic groups. Moreover, c-miR-486 level was positively related to SMI (r=0.334, P=0.003), whereas c-miR-146a level was positively associated with SMI (r=0.240, P=0.035) and handgrip strength (r=0.253, P=0.027). In the receiver operating characteristic analysis for predicting sarcopenia, the area under the curve in c-miR-486 was 0.708 (95% confidence interval: 0.561-0.855, P=0.008) and c-miR-146a was 0.676 (95% CI: 0.551-0.801, P=0.024). However, no significant relationships were observed between SMI/ handgrip strength/gait speed and plasma myeloperoxidase/interleukin-1?/interleukin-6 levels. In conclusion, myo-miRNA (c-miR-486) and inflammation-related miRNA (c-miR-146a) are superior to inflammatory peroxide/cytokines in plasma for serving as critical biomarkers of age-related sarcopenia.
REVIEW | doi:10.20944/preprints202311.1464.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: Systematic review; Sarcopenia; aged; Nutrition
Online: 23 November 2023 (04:25:26 CET)
Background: Sarcopenia, a subject of extensive research, has led to numerous clinical trials and systematic reviews (SR). These reviews aid healthcare professionals by summarizing results and conducting meta-analyses, enhancing reliability. However, the abundance of reviews complicates decision-making on sarcopenia management. To address this, SR of SR have emerged, consolidating data from various sources into comprehensive documents. Objective: to assess the isolated impact of dietary interventions on sarcopenia's diagnostic criteria for older individuals. Methods: a study protocol for a SR of SR, following Cochrane and PRISMA recommendations. The search strategy includes the MeSH ‘sarcopenia’ and its subheadings; ‘aged’ and its subheadings; ‘nutrition’ and its subheadings; and filter ‘systematic review’, performed at main databases. Selected studies must include older adults, submitted to nutritional interventions compared to control groups. Quantitative analyses will use inverse variance statistic method (random effects); the effect measures mean difference. Heterogeneity measured with Q-Test. Results: The results of this SR of SR will may provide valuable information about the sarcopenia treatment, deepening the knowledge about. Conclusion: this protocol is reproducible, requires low cost and personnel, and may allow a higher understanding on sarcopenia treatment and management on older people.
ARTICLE | doi:10.20944/preprints202307.1171.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: sarcopenia; physical fuction; oseoartritis; rehabilitation
Online: 18 July 2023 (07:41:01 CEST)
Background and Objectives:: Hip osteoarthritis is the main cause physical disability, also has a serious impact on the efficiency and independence of older people. The aim of the study was to analyze the relationship between hip osteoarthritis and the risk of sarcopenia. Our main hypothesis was whether the risk of sarcopenia, as measured by the SARC F questionnaire , is related to the physical fitness of older people with hip osteoarthritis. Materials and Methods: The study was conducted with the participation of 177 people of aged 65 or more, diagnosed hip osteoarthritis. The subjects were assessed using the SARC F questionnaire, the Short Physical Performance Battery (SPPB) and Timed Up and Go (TUG) test. The subjects were divided into two groups depending on the result they obtained in the SARC F questionnaire (group 1- SARC F <4, group 2 - SARC F ≥ 4). Results: There was a significant correlation between the results in the SARC F and the results of the TUG (p<0.001) and the SPPB test, both the SPPB total score (p<0.001)and its elements: SBBP chair stand test (p<0.001), SPPB balance test (p<0.001), SPPB gait speed test (p<0.001). Logistic regression of the SPPB and TUG predictors showed that in SARC F more than 4 predicted worse SPPB and TUG outcomes. In the SARC group, F above 4 increases the odds of poorer scores in SPPB OR=1.097; CI 95% 1.053-1.146 and TUG, OR=1.096; CI 95% 1.104-1.266. Conclusion: The study showed that the results obtained in the SARC F questionnaire correlate with the possibilities of physical functioning in patients with hip osteoarthritis SARC F is an inexpensive method that can be used to assess the risk of sarcopenia. Healthcare professionals, especially in primary care, should consider assessing the risk of sarcopenia especially in people with hip osteoarthritis.
ARTICLE | doi:10.20944/preprints202007.0741.v1
Online: 31 July 2020 (09:55:18 CEST)
Loss of muscle mass and strength are progressing with aging. Exercise is a beneficial method to prevent physical disfunction and habitual exercise improve the muscle quality. Therefore, we evaluated the effects of a long-term habitual exercise on the senescence-accelerated mice prone8 (SAMP8). 27wk SAMP8 were used in this study. Mice were classified into 28 (28w) and 44 weeks old. The 44-week group was divided into the sedentary group (44w) and a group exercising for 16 weeks (44w+Ex). The 44w+Ex performed habitual exercise from 28 to 44 weeks. Additionally, grip strength tests were performed with mice aged 28 and 44 weeks. Mice were dissected and collected muscle samples and measured muscle weight at 44w. Gastrocnemius was decreased in 44w but were unchanged in 44w+Ex. Grip strength in 44w was lower trend, but there was no change in 44w+Ex. The phosphorylation levels of Akt and p70S6K as a protein synthesis marker were decreased in 44w. Cytochrome c oxidase subunit IV(COXIV) mRNA and protein levels decreased in 44w. These results suggested that long-term habitual exercise attenuated muscle mass and strength decline through improving muscle protein synthesis and mitochondrial function. In conclusion, long-term habitual exercise attenuated muscle mass and strength decline.
ARTICLE | doi:10.20944/preprints202311.0400.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: overweight; sarcopenia; explosive force; neuromuscular markers; walking
Online: 7 November 2023 (06:32:44 CET)
Background: The rate of force development (RFD) plays a pivotal role not only in preventing falls but also in ensuring successful completion of many functional tasks that demand swift muscle power rather than prolonged strength. Despite its importance, there is limited compre-hensive research on the relationship between RFD and walking speed, especially in older adults with Sarcopenic Obesity (SO). Objective: to investigate the influence of obesity on neuromuscular markers in older adults with SO and to assess the relationship between neuromuscular markers and gait speed in older adults with SO. Methods: a cohort of 42 participants was categorized based on their BMI into two groups: the sarcopenic non-obese group (CG, n=22; age=81.13±4.02; BMI=25.13±3.35) and the sarcopenic obese group (SOG, n=20; age=77.71±2.95; BMI=34.46±3.25). Gait speed was measured using a 10-meter test. Additionally, the isometric strength of the plantar flexor muscles was assessed during maximal voluntary contractions. Absolute Peak force (aPeak, N) were documented at intervals of 50 ms (a50, N), 100 ms (a100, N), and 200 ms (a200, N), subsequently normalized to body mass (r50, r100, r200, N). The RFD was derived in two phases: from the start of the contraction to 50 ms (RFD50-100) and from 100 to 200 ms (RFD100-200) and calculated from the linear slop of the force – time curve (Δ force/Δ time). Conclusion: Obesity negatively impacts neuromuscular markers in older adults. Notably, RFD emerges as the dominant factor influencing gait speed, accounting for an impressive 51% of its variability, far surpassing the impact of relative peak force. This underscores the imperative of evaluating neuromuscular health in older adults with SO to provide insights into mobility out-comes.
ARTICLE | doi:10.20944/preprints202308.0874.v1
Subject: Public Health And Healthcare, Nursing Keywords: Renal insufficiency; Comorbidity; Frailty; Renal dialysis; Sarcopenia
Online: 10 August 2023 (16:15:04 CEST)
The study investigated the relationships between sarcopenia, frailty, and related factors in hemodialysis patients with chronic kidney disease. A prospective cross-sectional study with convenience sampling was conducted between August 2021 and February 2022 at a hospital-affiliated hemodialysis center. Ninety-six hemodialysis patients participated in the study. Quantitative data were collected with structured interviews. Sarcopenia was determined with a rapid screening tool. Frailty was determined with the Rockwood clinical frailty score. Descriptive analysis, Person Correlations, and Linear regression analysis were used to evaluate the associations between frailty, sarcopenia, and health-related factors in hemodialysis patients. The mean age of the participants was 65.4 11.5 years, with an average of 95.0 77.5 months of hemodialysis. The most common comorbidity was hypertension (72.9%), followed by diabetes mellitus (39.6%) and cardiovascular health problems (35.4%). A significant difference in frailty between sarcopenia patients and a healthy population (X2 =9.51, p <.001) was identified. There was a strong negative correlation (r= −.853, p<.001) between sarcopenia and frailty, while moderate correlations between sarcopenia and frailty in sarcopenia patients (r= −.66, p<.001) and a healthy population (r= −.58, p<.001) were observed. Age, body weight before dialysis, and hand grip strength were found to be potential predictors of sarcopenia and frailty. Left calf circumference was significantly associated with sarcopenia (ß= −.128, p = .049). Age, body weight before dialysis, and hand grip strength are potential predictors of sarcopenia and frailty in hemodialysis patients with chronic kidney disease. Comorbidities, which may be preventable, are common in this population.
ARTICLE | doi:10.20944/preprints202004.0218.v1
Subject: Medicine And Pharmacology, Endocrinology And Metabolism Keywords: type 2 diabetes mellitus; walking speed; sarcopenia
Online: 14 April 2020 (08:45:26 CEST)
Diabetes is a risk factor for mild cognitive impairment (MCI) and dementia. However, how the clinical characteristics of type 2 diabetic patients with MCI are linked to sarcopenia and/or its criterion remain to be elucidated. Japanese patients with type 2 diabetes mellitus were categorized into the MCI group for MoCA-J (the Japanese version of the Montreal cognitive assessment) score <26, and into the non-MCI group for MoCA-J ≥26. Sarcopenia was defined by a low skeletal mass index along with low muscle strength (handgrip strength) or low physical performance (walking speed <1.0 m/s). Univariate and multivariate-adjusted odds ratio models were used to determine the independent contributors for MoCA-J <26. Among 438 participants, 221 (50.5%) and 217 (49.5%) comprised the non-MCI and MCI groups, respectively. In the MCI group, age (61 ± 12 vs. 71 ± 10 years, p < 0.01) and duration of diabetes (14 ± 9 vs. 17 ± 9 years, p < 0.01) were higher than those in the non-MCI group. Patients in the MCI group exhibited lower hand grip strength, walking speed, and skeletal mass index, but higher prevalence of sarcopenia. Only walking speed (rather than muscle loss or muscle weakness) was found to be an independent determinant of MCI after adjusting for multiple factors, such as age, gender, BMI, duration of diabetes, hypertension, dyslipidemia, smoking, drinking, eGFR, HbA1c, and history of coronary heart diseases and stroke. In subgroup analysis, a group consisting of male patients aged ≥65 years, with BMI <25, showed a significant OR for walking speed. This is the first study to show that slow walking speed is a sole determinant for the presence of MCI in patients with type 2 diabetes. It was suggested that walking speed is an important factor in the prediction and prevention of MCI development in patients with diabetes mellitus.
REVIEW | doi:10.20944/preprints201808.0077.v1
Subject: Medicine And Pharmacology, Urology And Nephrology Keywords: sarcopenia; prognosis; biomarker; bladder cancer; urothelial carcinoma
Online: 3 August 2018 (16:05:54 CEST)
Sarcopenia, the degenerative and systemic loss of skeletal muscle mass, indicates patient frailty and impaired physical function. Sarcopenia can be caused by multiple factors, including advanced age, lack of exercise, poor nutritional status, inflammatory diseases, endocrine diseases, and malignancies. Recently, growing evidence has indicated the importance of sarcopenia in the management of patients with various cancers. Sarcopenia is associated with not only higher rates of treatment-related complications but also worse prognosis in cancer-bearing patients. In this article, we conducted a systematic literature review regarding the significance of sarcopenia as a prognostic biomarker of bladder cancer. We also reviewed recent studies focusing on the prognostic role of changes in skeletal muscle mass during the course of treatment in bladder cancer patients.
ARTICLE | doi:10.20944/preprints202311.0030.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Sarcopenia; MASLD; Liver Disease; Aging.; Steatotic liver disease
Online: 1 November 2023 (07:06:18 CET)
Introduction: Sarcopenia, muscle loss, often coexists with MASLD, a common liver disorder, which is more prevalent in those with sarcopenia. Sarcopenia also increases the risk of liver conditions like steatosis and fibrosis. Studies on sarcopenia in MASLD are common in developed countries, but fewer follow the EWGSOP2 guidelines in Brazil. Aim: to assess sarcopenia prevalence in MASLD patients. Methods: Cross-sectional study conducted at the Gastroen-terology/Hepatology Service of ISCMPA with patients diagnosed with MASLD. The EWGSOP2 criteria were used to evaluate sarcopenia. Categorical data presented as absolute and relative frequency; parametric continuous data ex-pressed as mean±standard deviation; non-parametric continuous data as me-dian and IQR. Gender differences in were analyzed using Fisher's Exact Test or Chi-squared tests, and for continuous variables, T Student tests (parametric) and Mann-Whitney U tests for independent samples (non-parametric). The significance level was set at 5% (p<0.05). Results: The study involved 103 MASLD patients with an average age of 60.39 years, comprising 48 (46.60%) adults and 55 (53.40%) older individuals. Concerning sarcopenia diagnosis, four individuals exhibited decreased muscle strength; two had reduced MME (sarcopenia); and one showed decreased walking speed (severe sarcopenia). Among the participants, 63 (60.6%) were physically active. 35 (62.5%) had mild to moderate steatosis, while 21 (37.5%) had severe steatosis. In terms of EHNA, 13 subjects (24.08%) had moderate to severe EHNA. Regarding fibrosis classi-fication, 68 (72.34%) individuals had undetermined or high probability based on the NAFLD score, with higher prevalence in males (n=23; 88.5%). Fibrosis assessment via liver biopsy revealed 27 (28.72%) in F1 and F2 and 15 (16.96%) in F3 and F4. Stratification of fibrosis into F3 and F4 was more com-mon among men (n=9; 47.4%). Conclusion: Most of the population was physi-cally active. The parameters indicating sarcopenia exceeded the thresholds recommended by EWGSOP2. The prevalence of sarcopenia was low in individuals with MASLD.
ARTICLE | doi:10.20944/preprints202307.0508.v1
Subject: Biology And Life Sciences, Aging Keywords: ageing; sarcopenia; dynapenia; skeletal muscle atrophy; denervation; behavior
Online: 10 July 2023 (03:58:41 CEST)
The facultative loss of muscle mass and function during aging (sarcopenia) poses a serious threat to our independence and health. Much of what we know about sarcopenia derive from studies on small rodents which serve as models for the human condition. Here we used outbred male rats to study the natural history of sarcopenia with the aim to compare behavioral motor deficits with degree of muscle wasting and to find processes underlying the preclinical phase of sarcopenia. Selected metrics were validated in female rats. We used the soleus muscle because of its long duty cycles in everyday life and significance for postural control. The results show that gait and coordination remain intact through middle age (12-18 months; 40%-60% of median lifespan) when muscle mass relative to body weight is largely maintained. The muscle, however, show multiple signs of remodeling with a shift in myofiber-type composition towards type I, increased number of hybrid fibers and fibers expressing embryonic myosin. In parallel with the shift in fiber type prevalence, fiber type clustering increased. The latter combined with a transcriptional upregulation of nicotinic acetylcholine receptor subunit (CHRN ), NCAM and Myogenin (MYOG) suggests a remodeling driven by myofiber denervation. Additional stigmata were increased number of central nuclei, transcriptional upregulation of Smad3, FBXO32, and MuRF1mRNAs; unaltered density of satellite cells (SC) and Catenin mRNA. In early (25-month-old) and advanced (30-month-old) aging, gait and coordination deteriorate as loss of muscle mass progresses. In late middle age and early aging because of a type II atrophy (>50%), followed by type I atrophy (>50%). Number of myofiber did not correlate with this process. At advance age, the atrophy is accompanied by a decrease in SC and Catenin mRNA while several transcripts upregulated earlier-on were downregulated. In contrast, glial-derived nerve growth factor (GDNF) mRNA abundance peaked at endpoint. We conclude that sarcopenia in the rat as in humans, has a long preclinical phase where the muscle undergoes extensive remodeling to preserve muscle mass and function. The data supports the notion that myofiber denervation is the instigating mechanism, initially affecting large type II motor units (MUs) and at more advanced stage also the smaller type I MUs.
ARTICLE | doi:10.20944/preprints202306.0738.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: age; obesity; gait; physical activity; neuromuscular system; sarcopenia
Online: 12 June 2023 (03:02:19 CEST)
The potential impact of a specific physical activity program on biomechanical gait parameters and neuromuscular strategies around the ankle joint in older adults with sarcopenic obesity (SO) remains largely unexplored. The objective of this study was to investigate the effectiveness of a 24-week Posture, Strengthening, and Motricity (PSM) program in improving neuromuscular strategies and biomechanical gait parameters in older adults with SO. 40 Participants were randomly assigned to either the trained group (TG) and the control group (CG). Only the TG received the PSM program. Standardized evaluations were performed before and after the intervention, including walking tests on an instrumented gait analysis treadmill to evaluate biomechanical gait parameters and EMG activity of ankle muscles. After the PSM program, TG exhibited an increase in comfortable walking speed (+80%, p<0.001) and step length (+38%, p<0.05). Moreover, TG demonstrated a reduction in CoP velocity (-26%, p<0.01). These gait modifications were associated with a decreased muscle activity during the different gait phases (p<0.05). The PSM program effectively improved gait, and neuromuscular capacities in older adults with SO. Notably, Results sheds light on the remarkable trainability of neuromuscular capacities in older adults with SO, despite the adverse effects of aging and obesity.
ARTICLE | doi:10.20944/preprints202304.0361.v1
Subject: Medicine And Pharmacology, Other Keywords: Falls; Falls risk assessment tools; geriatric medicine; sarcopenia
Online: 14 April 2023 (09:38:29 CEST)
Background: Falls risk assessment tools are used in hospital inpatient settings to identify pa-tients at increased risk of falls (which may be related to muscle loss/sarcopenia) to guide and target interventions for falls prevention. In 2022, Western Health, Melbourne, Australia, intro-duced a new falls risk assessment tool, the Western Health St. Thomas’ Risk Assessment Tool (WH-STRATIFY), a modified version of The Northern Hospital’s risk tool (TNH-STRATIFY), which replaced the Peninsula Health Risk Screening Tool (PH-FRAT). Aims: To determine the predictive accuracy of three falls risk assessment tools (PH-FRAT, TNH-STRATIFY and WH-STRATIFY) on admission to Geriatric Evaluation Management (GEM) units. Method: A retrospective observational study was conducted on four GEM units. Data was col-lected on 54 consecutive patients who fell during admission and 62 randomly sampled patients who did not fall between December 2020 and June 2021. Participants were scored against three falls risk assessment tools. The event rate Youden (Youden IndexER) indices were calculated and compared using default and optimal cut points to determine which tool was most accurate for predicting falls. Results: Using default cut points to compare falls assessment tools, TNH-STRATIFY had the highest predictive accuracy (Youden IndexER = 0.20, 95% confidence interval CI = 0.07, 0.34). The PH-FRAT (Youden IndexER = 0.01 and 95% CI = -0.04, 0.05) and WH-STRATIFY (Youden IndexER = 0.00 and 95% CI = -0.04, 0.03) were statistically equivalent and not predictive of falls compared to TNH-STRATIFY. When calculated optimal cut points were applied, predictive accuracy im-proved for PH-FRAT (Cut point 17, Youden IndexER = 0.14 and 95% CI = 0.01, 0.29) and WH-STRATIFY (Cut point 7, Youden IndexER = 0.18 and 95% CI = 0.00, 0.35). Overall, all tools had low predictive accuracy for falls. Conclusion: TNH-STRATIFY had the highest predictive accuracy for falls. The predictive accu-racy of WH-STRATIFY improved and was significant when the calculated optimal cut point was applied. The optimal cut points of falls risk assessment tools should be determined and validated in different clinical settings to optimise local predictive accuracy, enabling targeted falls risk mitigation strategies and resource allocation.
ARTICLE | doi:10.20944/preprints202008.0118.v1
Subject: Biology And Life Sciences, Cell And Developmental Biology Keywords: Sarcopenia; β-hydroxy-β-methyl butyrate Calcium; Black ginger
Online: 5 August 2020 (09:51:06 CEST)
Muscle mass and strength decrease with aging, but habitual exercise can maintain muscle health. β-Hydroxy-β-methyl butyrate calcium (HMB) and black ginger (BG) are anti-oxidants that have been reported to improve muscle protein metabolism and energy production; these molecules may have synergistic effects. The senescence-accelerated mouse-prone 8 (SAMP8) model is a useful model of muscle aging. Therefore, in this study, we explored how the combination of habitual exercise, HMB, and BG affected muscle aging. We used 28-week-old SAMP8 mice divided into five groups: control, exercise (Ex), Ex+BG, Ex+HMB, and Ex+BG+HMB (Ex+Comb). Mice were required to run on a treadmill for 16 weeks at 5 days per week. In 44-week-old mice, grip strength tests and dissection were conducted. Muscle weight was measured, and the gastrocnemius muscle was subjected to quantitative polymerase chain reaction and immunoblotting. Muscle mass and strength were preserved in the Ex+Comb group, and mitochondrial function was preserved through suppressing oxidative stress. Muscle protein synthesis signaling was improved in the Ex+Comb group. Autophagy and the ubiquitin system were normalized by Ex+Comb treatment. Overall, habitual exercise and HMB plus BG treatment maintained muscle health by suppressing oxidative stress, preserving mitochondrial function, and maintaining muscle protein metabolism in SAMP8 mice.
ARTICLE | doi:10.20944/preprints201904.0240.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: sarcopenia; slow gait speed; cognitive impairment; older adult; aging
Online: 22 April 2019 (11:28:59 CEST)
Cognitive impairment and sarcopenia may share common risk factors and pathophysiological pathways. This study was performed to examine the association between impairments in specific cognitive domains and sarcopenia (and its defining components) in a large group of community-dwelling older adults. Cross-sectional analysis was performed on the baseline data of 3,014 adults aged 70–84 years enrolled in the Korean Frailty and Aging Cohort Study (KFACS). The final analysis included 1,887 adults underwent dual-energy X-ray absorptiometry and cognitive function assessments. Those with disability in activities of daily living, dementia, severe cognitive impairment, Parkinson’s disease, musculoskeletal complaints, neurological disorders, or who were illiterate were excluded. Cognitive function was assessed using the Korean version of the Consortium to Establish a Registry for Alzheimer’s Disease Assessment Packet, the Frontal Assessment Battery. For sarcopenia, we used the diagnostic criteria of the Asian Working Group for Sarcopenia. The prevalence of sarcopenia was 9.6% for men and 7.6% for women. Sarcopenia (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.04–2.99) and slow gait speed (OR 2.58, 95% CI 1.34–4.99) were associated with cognitive impairment in men. Only slow gait speed (OR 1.88, 95% CI 1.05–3.36) was associated with cognitive impairment in women. Sarcopenia is associated with cognitive impairment mainly due to slow gait speed. Our results suggested that cognitive impairment domains, such as processing speed and executive function, are associated with sarcopenia-related slow gait speed.
REVIEW | doi:10.20944/preprints201806.0152.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: protein; skeletal muscle; sarcopenia; gut microbiome; metabolome; diet; supplementation
Online: 11 June 2018 (11:05:04 CEST)
Muscle mass, strength and physical function are known to decline with age. This is associated with the development of geriatric syndromes including sarcopenia and frailty. These conditions are associated with disability, falls, longer hospital stay, higher readmission rates, institutionalisation, osteoporosis, and death. Moreover, they are associated with reduced quality of life, as well as substantial costs to health services around the world. Dietary protein is essential for skeletal muscle function. Older adults have shown evidence of anabolic resistance, where greater amounts of protein are required to stimulate muscle protein synthesis and therefore require higher daily amounts of dietary protein. Research shows that resistance exercise has the most beneficial effect on preserving skeletal muscle. A synergistic effect has been noted when this is combined with dietary protein, yet studies in this area lack consistency. This is due, in part, to the variation that exists within dietary protein, in terms of dose, quality, source, amino acid composition and timing. Research has targeted participants that are replete in dietary protein with negative results. Inconsistent measures of muscle mass, muscle function, physical activity and diet are used. This review attempts to summarise these issues, as well as introduce the possible role of the gut microbiome and its metabolome in this area.
ARTICLE | doi:10.20944/preprints202311.0680.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: sarcopenia; delayed blood pressure recovery; orthostatic hypotension; orthostatic haemodynamics; orthostasis
Online: 10 November 2023 (07:45:32 CET)
Background: Along with sarcopenia, delayed blood pressure (BP) recovery after standing and orthostatic hypotension (OH) are among key clinical challenges associated with ageing. Previous studies have reported an association between sarcopenia and delayed orthostatic BP recovery and OH. However, the haemodynamic mechanisms underlying this association remain unclear. Methods: 107 attendees to a falls and syncope clinic aged 50+ years underwent an active stand test with non-invasive beat-to-beat haemodynamic measurement. Hand grip strength and 5-chair stands time were measured. Muscle mass was estimated using bioelectrical impedance analysis, and participants were classified as non-sarcopenic and sarcopenic. Mixed effects models with linear splines were used to model the effect of sarcopenia status on Modelflow®-derived mean arterial pressure (MAP), cardiac output (CO), total peripheral resistance (TPR), stroke volume (SV) and heart rate (HR) after standing, while controlling for potential confounders. Results: Sarcopenia was associated with: attenuated recovery of MAP in the 10-20s period after standing (β -0.67, P<0.001); attenuated rise to peak (0-10s) and recovery from peak (10-20s) of CO (β -0.05, P<0.001; β 0.06, P<0.001); attenuated recovery (10-20s) of TPR from nadir (β -0.02, P<0.001) and attenuated recovery from peak (10-20s) of SV (β 0.54, P<0.001). HR was not significantly associated with sarcopenia status at any time interval after standing. Conclusion: The attenuated BP recovery after standing seen in sarcopenia appears to be driven by initial diminished peak of CO followed by attenuated recovery of CO from peak and TPR from nadir. The CO finding appears to be driven by SV rather than HR. Potential mechanisms for these findings include: cardio-sarcopenia, the effects of sarcopenia on the autonomic nervous system and/or the skeletal muscle pump.
BRIEF REPORT | doi:10.20944/preprints202307.1015.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: aging; dietary protein; hand-grip strength; physical function; rehabilitation; sarcopenia
Online: 14 July 2023 (11:32:28 CEST)
It is estimated that about 50% of geriatric rehabilitation patients suffer from sarcopenia. Thereby, malnutrition is frequently associated with sarcopenia and dietary intake is the main modifiable risk factor. During hospitalization, older adults are recommended to consume more dietary protein than the current recommended dietary allowance of 0.8 g/kg body weight per day to optimize the recovery of muscular strength and physical function. This prospective study examined the effect of a short-term protein supplementation with protein-enriched foods and drinks on hand-grip strength, nutritional status and physical function in older patients at risk of malnutrition during a three week inpatient orthopedic rehabilitation stay. The Mini Nutritional Assessment (MNA) was used to assess malnutrition. Patients with a MNA score ≤ 23.5 points were randomly assigned to an intervention group (goal: to consume 1.2–1.5 g protein/kg body weight per day) or a control group (standard care). Both groups carried out the same rehabilitation program. Physical recovery parameters were determined at admission and discharge. There was a trend for participants in the intervention group to consume more protein than the control group (P = 0.058): 95.3 (SD 13.2) g/day as compared to 77.2 (SD 24.2) g/day, which corresponds to a mean protein intake of 1.6 (SD 0.3) g/kg/day vs. 1.3 (SD 0.5) g/kg/day. Dietary protein supplementation increased body weight by an average of 0.9 (SD 1.1) kg and fat mass by an average of 0.9 (SD 1.2) kg as compared with baseline (P = 0.039 and P = 0.050, respectively). There was no significant change in hand-grip strength, body composition and physical function. In conclusion, a short-term intervention with protein-enriched foods and drinks enabled older patients at risk of malnutrition to increase their protein intake to levels that are higher than their required intake. In these older individuals with appropriate protein intake, dietary protein supplementation did not result in a greater improvement in physical recovery outcomes during short-term inpatient rehabilitation. The intervention improved dietary protein intake, but further research (e.g., a full-scale randomized controlled trial with sufficient power) is required to determine the effects on physical function outcomes.
REVIEW | doi:10.20944/preprints202309.1738.v1
Subject: Biology And Life Sciences, Aging Keywords: Sarcopenia; Zebrafish; Age-related muscle deficits; Aging; Biomarkers; Electrical Impedance Myography
Online: 26 September 2023 (13:38:16 CEST)
Abstract: Sarcopenia poses a significant challenge to public health and can severely impact the quality of life of aging populations. Despite extensive efforts to study muscle degeneration using traditional animal models, there is still a lack of effective diagnostic tools, precise biomarkers, and treatments for sarcopenia. Zebrafish models have emerged as powerful tools in biomedical research, providing unique insights into age-related muscle disorders like sarcopenia. The advantages of using zebrafish models include their rapid growth outside of the embryo, optical transparency during early developmental stages, high reproductive potential, ease of husbandry, compact size, and genetic tractability. By deepening our understanding of the molecular processes underlying sarcopenia, we may develop novel diagnostic tools and effective treatments that can improve the lives of aging individuals affected by this condition. This review aims to explore the unique advantages of zebrafish as a model for sarcopenia research, highlight recent breakthroughs, outline potential avenues for future investigations, and emphasize the distinctive contributions that zebrafish models offer. Our research endeavors to contribute significantly to addressing the urgent need for practical solutions to the impact of sarcopenia on aging populations, ultimately striving to enhance the quality of life for individuals affected by this condition.
ARTICLE | doi:10.20944/preprints202309.1015.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: Physical exercises; obesity; sarcopenia; static balance; proactive balance; ankle muscle activation
Online: 15 September 2023 (05:25:01 CEST)
Despite limited research on the effects of a combined physical exercises on static and proactive postural control and neuromuscular functions in older adults with sarcopenic obesity (SO), this study addresses the gap by examining the efficacy of a 4-month Total Mobility Plus (TMP) regimen. The study enrolled 40 older adults with SO, split into an intervention group (n=25, mean age = 76.1 ± 3.5 years; mean BMI = 34.4 ± 4.0 kg/m²) and a control group (n=25, mean age = 75.9 ± 5.4 years; mean BMI = 32.9 ± 2.3 kg/m²). Participants in the IG engaged in 60-minute TMP sessions three times a week for four months, while the CG maintained their typical daily activities. Standardized evaluations were performed before and after the intervention, including the Romberg and Timed Up and Go (TUG) tests, Center of pressure (CoP) parameters during different conditions, muscle activation and strength of plantar and dorsal flexors. Post-intervention results revealed significant reduction of the standing time measured in the Romberg (-15.6%, p<0.05), and TUG (-34.6%, p<0.05) tests. Additionally, CoP area and velocity, were notably reduced in various conditions (p<0.05). Postural control improvements were associated with an increase of strength and decrease of ankle muscle activation. These findings validate the TMP program as a safe and effective method for enhancing static and proactive postural control and neuromuscular capabilities in older adults with SO.
REVIEW | doi:10.20944/preprints202308.0516.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: exercise; intracellular signals; nutrition; protein foods; protein synthesis; sarcopenia; skeletal muscle.
Online: 8 August 2023 (05:02:08 CEST)
The development of sarcopenia in the elderly is associated to many potential factors and/or processes, that impair the renovation and the maintenance of skeletal muscle mass and strength as ageing progresses. Among them, a defect by skeletal muscle to respond to anabolic stimuli is to be considered. Common anabolic stimuli/signals in skeletal muscle are hormones (insulin, growth hormones, IGF-1, androgens, β-agonists such epinephrine), substrates (amino acids as protein precursors on top, but also glucose and fat, as source of energy), metabolites (such as β-agonists and HMB), some cytokines, various biochemical/ intracellular mediators), physical exercise, neurogenic and immune-modulating factors, etc. Each of them may exhibit a reduced effect upon skeletal muscle as ageing progresses. In this review article, we will concisely overview the effects of anabolic signals on muscle metabolism, as well as currently available evidence of a resistance, at skeletal muscle level, to any of the above-mentioned anabolic factors, from both in vitro and in vivo studies.
REVIEW | doi:10.20944/preprints202212.0079.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Skeletal muscle; sarcopenia; osteoarthritis; osteoporosis; rheumatoid arthritis; oligonucleotides; cartilage; bone; synovium
Online: 5 December 2022 (15:23:19 CET)
Age-related disorders of the musculoskeletal system including sarcopenia, osteoporosis and arthritis represent some of the most common chronic conditions worldwide, for which there remains a great clinical need to develop safer and more efficacious pharmacological treatments. Collectively, these conditions involve multiple tissues, including skeletal muscle, bone, articular cartilage and the synovium within the joint lining. In this review, we discuss the potential for oligonucleotide therapies to combat the unmet clinical need in musculoskeletal disorders by evaluating the successes of oligonucleotides to modify candidate pathological gene targets and cellular processes in relevant tissues and cells of the musculoskeletal system. Further, we discuss the challenges that remain for the clinical development of oligonucleotides therapies for musculoskeletal disorders and evaluate some of the current approaches to overcome these.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: sarcopenia; non-alcoholic fatty liver disease; obesity; skeletal muscle mass; inflammation
Online: 14 December 2020 (08:20:04 CET)
Although sarcopenia is known to be a risk factor for non-alcoholic fatty liver disease (NAFLD), whether NAFLD is a risk factor for the development of sarcopenia is not clear. We investigated bidirectional relationships between NAFLD and low skeletal muscle mass index (LSMI) using three different datasets. Participants were classified into LSMI and normal groups. LSMI was defined as a body mass index (BMI)-adjusted appendicular skeletal muscle mass <0.789 in men and <0.512 in women or as the sex-specific lowest quintile of BMI-adjusted total skeletal muscle mass. NAFLD was determined according to NAFLD liver fat score or abdominal ultrasonography. The NAFLD groups showed a higher hazard ratios (HRs) with 95% confidence intervals (CIs) for LSMI than the normal groups (HRs=1.213, 95% CIs=1.050–1.402). The LSMI groups also showed a higher HRs with 95% CIs for NAFLD than normal groups (HRs=1.564, 95% CIs=1.378–1.775). Participants with NAFLD had consistently less skeletal muscle mass over 12 years of follow-up. In conclusion, LSMI and NAFLD showed a bidirectional relationship. Maintaining muscle mass should be emphasized in the management of NAFLD.
REVIEW | doi:10.20944/preprints202305.1990.v1
Subject: Biology And Life Sciences, Aging Keywords: Tryptophan; Kynurenine pathway; Aging; older adults; Inflammation; Osteoporosis; Sarcopenia; Frailty; Biomarkers; Osteosarcopenia
Online: 29 May 2023 (07:32:17 CEST)
Tryptophan is an essential nutrient required to produce niacin (vitamin B3), which is needed for energy metabolism and DNA production. Alterations in tryptophan metabolism could have significant effects on aging and musculoskeletal health. The kynurenine pathway, the main catabolic route of tryptophan, is modulated by inflammatory factors, which are increased in older persons, a process known as inflammaging. Osteoporosis, sarcopenia, osteosarcopenia and frailty have also been linked with chronic increased levels of inflammatory factors. Due to the disruption of the kynurenine pathway by chronic inflammation and/or changes in the gut microbiota, serum levels of toxic kynurenines are increased and have been associated with osteoporosis, sarcopenia and frailty. In contrast, anabolic end products of this pathway, such as picolinic acid, have demonstrated a beneficial effect on bone and muscle. In addition, recent studies have shown that physical activity can modulate this pathway by promoting the secretion of anabolic kynurenines. According to the evidence collected, kynurenines could have a promising role as biomarkers for osteoporosis sarcopenia, osteosarcopenia and frailty in older persons. In addition, some of these metabolites could become important targets for developing new pharmacological treatments for these conditions.
ARTICLE | doi:10.20944/preprints202304.0939.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: oral health care; older people; multimorbidity; polypharmacy; frailty; sarcopenia; disability; care dependency
Online: 26 April 2023 (03:23:46 CEST)
The oral health of older individuals can be negatively impacted by various systemic health factors, leading to rapid oral health deterioration. Older people are at risk of experiencing adverse reactions to medications due to multimorbidity, polypharmacy, and changes in pharmacokinetics and pharmacodynamics. Hyposalivation, a significant side effect of some medications, can be induced by both the type and number of medications used. Frailty, disability, sarcopenia, care dependency, and limited access to professional oral healthcare can also compromise the oral health of older people. To prevent rapid oral health deterioration, a comprehensive approach is required that involves effective communication between oral healthcare providers, other healthcare providers, and informal carers. Regardless of their health status, it is crucial to prioritize the well-being of older people. Oral healthcare providers have a responsibility to advocate for the importance of maintaining adequate oral health and to raise awareness of the serious consequences of weakened oral health. By doing so, we can prevent weakened oral health from becoming a geriatric syndrome.
REVIEW | doi:10.20944/preprints202012.0822.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Sarcopenia; Non-alcoholic Fatty Liver Disease; Obesity, Insulin Resistance; Prevalence; Metabolic Diseases
Online: 31 December 2020 (15:34:29 CET)
Non-alcoholic fatty liver disease (NAFLD) continues to rise and has become the most common cause of chronic liver disease among all ages and ethnicities. Metabolic disorders such as obesity and insulin resistance are closely associated with sarcopenia and NAFLD. Sarcopenic obesity is a clinical disorder characterized by the simultaneous loss of skeletal muscle and gain of adipose tissue. It is associated with worse outcomes in individuals with NAFLD. It is projected that NAFLD and sarcopenia will rise as the prevalence of obesity continues to increase at an unparallel rate. Recently, sarcopenia and sarcopenic obesity have gained considerable interest, but we still lack a well-defined definition and a management approach. Therefore, it is imperative to continue shining the light on this topic and better understand the underlying mechanism as well as treatment options. In this review article, we aimed to address the pathophysiology, impact, and outcomes of sarcopenic obesity on NAFLD.
ARTICLE | doi:10.20944/preprints201908.0032.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: aging; skeletal muscle; sarcopenia; frailty; chromatin; epigenetic changes; histone modifications; Nothobranchius furzeri
Online: 2 August 2019 (12:17:03 CEST)
Aging associates with progressive loss of skeletal muscle function leading up to sarcopenia, a process characterized by impaired mobility and weakening of muscle strength. Molecular mechanisms underpinning sarcopenia are still poorly characterized. Since aging associates with profound epigenetic changes, epigenetic landscape alteration analysis in the skeletal muscle promises to highlight molecular mechanisms of age-associated sarcopenia. The study was conducted exploiting the short-lived turquoise killifish Nothobranchius furzeri (Nfu), a relatively new model for aging studies. The epigenetic analysis suggested for a less accessible and more condensed chromatin in old Nfu skeletal muscle. Specifically, an accumulation of heterochromatin regions was observed as consequence of increased levels of H3K27me3, HP1alpha, polycomb complex subunits and senescence associated heterochromatic foci (SAHFs). Consistently, euchromatin histone marks, including H3K9ac, decreased. The integrative bioinformatics analysis of RNASeq and ChIPSeq, related to skeletal muscle of Nfu at different ages, revealed a down-modulation of genes involved in cell cycle, differentiation and DNA repair and an up-regulation of inflammation and senescence genes. Undoubtedly, more studies are needed to disclose the detailed mechanisms, but this approach revealed an unprecedented specific features of Nfu skeletal muscle aging, potentially associated with sarcopenia onset and consequent impairment of swimming and mobility typical of old Nfu.
ARTICLE | doi:10.20944/preprints201710.0149.v1
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: aging; skeletal muscle; grip strength; sarcopenia; physical function; bone mineral density; magnesium
Online: 23 October 2017 (11:26:29 CEST)
Although fragility fractures, osteoporosis, sarcopenia and frailty are becoming more prevalent in our aging society the treatment options are limited and preventative strategies are needed. Despite magnesium being integral bone and muscle physiology the relationship between dietary magnesium and skeletal muscle and bone health has not been investigated concurrently before. We analysed cross-sectional associations between dietary magnesium and skeletal muscle mass (as fat free mass – FFM), grip strength and bone density (BMD) in 156,575 men and women aged 39-72 years from the UK Biobank cohort. FFM was measured with bioelectrical impedance and expressed as the percentage of body weight (FFM%) or divided by body mass index (FFMBMI). Adjusted mean grip strength, FFM%, FFMBMI, and BMD were calculated according quintiles of dietary magnesium, correcting for covariates. Significant inter-quintile differences across intakes of magnesium existed in men and women respectively of 1.1% and 2.4% for grip strength, 3.0% and 3.6% for FFM%, 5.1% and 5.5% for FFMBMI, and 2.9% and 0.9% for BMD. These associations are as great or greater than annual measured losses of these musculoskeletal outcomes indicating potential clinical significance. Our study suggests that dietary magnesium may play a role in musculoskeletal health and have relevance for population prevention strategies for sarcopenia, osteoporosis and fractures.
REVIEW | doi:10.20944/preprints202310.2087.v1
Subject: Biology And Life Sciences, Aging Keywords: aging; chronodisruption; clock genes; Bmal1; inflammaging; oxidative stress; mitochondria; skeletal muscle; sarcopenia; melatonin
Online: 1 November 2023 (03:02:46 CET)
Sarcopenia is an age-related condition that involves a progressive decline in muscle mass and function, leading to increased risks of falls, frailty, and mortality. Although the exact mechanisms are not fully understood, aging-related processes like inflammation, oxidative stress, reduced mitochondrial capacity, and cell apoptosis contribute to this decline. Disruption of the circadian system with age may initiate these pathways in skeletal muscle, preceding the onset of sarcopenia. At present, there is no pharmacological treatment for sarcopenia, only resistance exercise and proper nutrition may delay its onset. Melatonin, derived from tryptophan, emerges as an exceptional candidate for treating sarcopenia due to its chronobiotic, antioxidant, and anti-inflammatory properties. Its impact on mitochondria, organelle where it is synthesized and crucial in aging skeletal muscle, further highlights its potential. In this review, we discuss the influence of clock genes in muscular aging, with special reference to peripheral clock genes in the skeletal muscle, as well as their relationship with melatonin, which is proposed as a potential therapy against sarcopenia.
ARTICLE | doi:10.20944/preprints202307.0896.v1
Subject: Public Health And Healthcare, Primary Health Care Keywords: type 2 diabetes mellitus; sarcopenia; serum vitamin D3 levels; nutritional intake; physical performance
Online: 13 July 2023 (08:08:00 CEST)
The study aimed to estimate the prevalence and association between sarcopenia and blood biochemical parameters, nutritional intake, anthropometric measurements, physical performance, and physical activity in patients with Type 2 Diabetes Mellitus (T2DM). According to the diagnosis criteria of the Asian Working Group for Sarcopenia (AWGS) in 2019, 110 patients with T2DM (aged: 50–80 years) were divided into three groups: Non-sarcopenia (n = 38), Possible Sarcopenia (n = 31, 28.2%), and Sarcopenia (n = 41, 37.3%). Blood samples were collected and nutritional intake was evaluated by a registered dietitian. A food frequency questionnaire and Godin leisure-time exercise questionnaire were used to assess their daily vitamin D intake and physical activity. There were significant differences in age, serum vitamin D3 levels, nutritional intake, anthropometric measurements, and physical performance between the three groups. In elderly patients with T2DM, there was a significant association between sarcopenia with BMI, body fat percentage (BF%), and dietary energy and protein intake. Low serum vitamin D3 is a significant risk factor for possible sarcopenia.
REVIEW | doi:10.20944/preprints202101.0120.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mTOR; ATP; protein synthesis; autophagy; amino acids; nutrition; adipose tissue; muscle; sarcopenia; mitochondria
Online: 6 January 2021 (14:32:22 CET)
Background. Sarcopenia, defined as the loss of skeletal muscle mass and function, is a major clinical problem in many chronic illnesses, in cancer and in the elderly. Exercise and adequate nutrition, peculiarly dependents on availability of essential amino acids, considered the primary strategies for prevention and treatment of protein synthetic deficits, affect both the efficient scavenging of aged and overused protein molecules and the renewal, by maintaining muscular protein synthesis. Many questions still remain about the regulation of protein syntheses and degradation. Degradation of inefficient proteins or organelles is performed by the sum of micro and macro-autophagy plus ubiquitin-proteasome system, activities known as proteostasis, necessary to preserve and promote protein masses and consequently, the body’s reserves. However, how protein synthesis is regulated, and how activation of the mTOR complex may modulate and transduce the flow of information provided by exercise and nutrition to balance proteostasis and syntheses, is far from being fully understood. We suggest that energy production and availability, thus also mitochondria, may have a pivotal role in synchronizing activity and functional outcomes of protein syntheses, and that those syntheses, since higly energy demanding, are main effectors of AMPK dependent autophagy activation by consuming ATP and producing AMP. Conclusion. While in normal conditions protein syntheses drive autophagy activation by decreasing ATP to AMP ratio, conversely autophagy may be inefficiently activated when chronic both low production and consumption of ATP would result in lowest concentrations of AMP, and therefore both blunted rates of protein syntheses and autophagy would be observed. We suggest that this functional hypothesis may explain sarcopenia in many pathological conditions , as in cancer or in aging muscles.
ARTICLE | doi:10.20944/preprints202007.0320.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: sarcopenia; hepatocellular carcinoma; grip strength; skeletal muscle index; lenvatinib; modified albumin-bilirubin grade
Online: 15 July 2020 (08:45:55 CEST)
Although sarcopenia is characterized by a loss of muscle strength and skeletal muscle mass, few studies have evaluated the effect of muscle strength on hepatocellular carcinoma (HCC) patients. We separately evaluated the impact of sarcopenia-related factors (grip strength [GS] and the skeletal muscle index [SMI]) on the survival among lenvatinib-treated unresectable HCC (u-HCC) patients. This single-center cohort study was conducted at a university hospital. The study population included 63 lenvatinib-treated u-HCC patients managed between April 2018 and April 2020. A decreased GS and decreased SMI were found in 21 (33.3%) and 22 (34.9%) patients, respectively. The overall survival (OS) of the normal GS group was significantly higher than that of the decreased GS group, while that of the normal and decreased SMI groups did not differ markedly. There were no significant differences in the progression-free survival between the normal GS and decreased GS groups or the normal SMI and decreased SMI groups. A multivariate Cox proportional hazards model showed that ALBI2b (hazard ratio [HR] 4.39) and a decreased GS (HR 3.55) were independently associated with an increased risk of poor prognosis. In addition to the hepatic functional reserve, a decreased GS was a poor prognostic factor in lenvatinib-treated u-HCC patients.
ARTICLE | doi:10.20944/preprints201706.0081.v3
Subject: Medicine And Pharmacology, Dietetics And Nutrition Keywords: age-related skeletal muscle loss; sarcopenia; malnutrition risk assessment; DXA; multi-frequency BIA; aging
Online: 23 August 2017 (17:57:14 CEST)
Background: Appendicular skeletal muscle (or lean) mass (ALM) estimated using dual-energy X-ray absorptiometry (DXA) is considered to be a preferred method for sarcopenia studies. However, DXA is expensive, has limited portability, and requires radiation exposure. Bioelectrical impedance analysis (BIA) is inexpensive, easy to use, and portable; thus BIA might be useful in sarcopenia investigations. However, a large variety of models have been commercially supplied by different companies, and for most consumer products, the equations estimating ALM are not disclosed. It is therefore difficult to use these equations for research purposes. In particular, the BIA equation is often age-dependent, which leads to fundamental difficulty in examining age-related ALM loss. The aims of the current study were as follows: (1) to develop and validate an equation to estimate ALM using multi-frequency BIA (MF-BIA) based on theoretical models, and (2) to establish sarcopenia cutoff values using the equation for the Japanese population. Methods: We measured height (Ht), weight, and ALM obtained using DXA and a standing-posture 8-electrode MF-BIA (5, 50, 250 kHz) in 756 Japanese individuals aged 18 to 86-years-old (222 men and 301 women as developing equation group and 97 men and 136 women as a cross validation group). The traditional impedance index (Ht2/Z50) and impedance ratio of high and low frequency (Z250/Z5) of hand to foot values were calculated. Multiple regression analyses were conducted with ALM as dependent variable in men and women separately. Results: We created the following equations: ALM = (0.6947 × (Ht2/Z50)) + (−55.24 × (Z250/Z5)) + (−10,940 × (1/Z50)) + 51.33 for men, and ALM = (0.6144 × (Ht2/Z50)) + (−36.61 × (Z250/Z5)) + (−9332 × (1/Z50)) + 37.91 for women. Additionally, we conducted measurements in 1624 men and 1368 women aged 18 to 40 years to establish sarcopenia cutoff values in the Japanese population. The mean values minus 2 standard deviations of the skeletal muscle mass index (ALM/Ht2) in these participants were 6.8 and 5.7 kg/m2 in men and women, respectively. Conclusion: The current study established and validated a theoretical and age-independent equation using MF-BIA to estimate ALM and provided reasonable sarcopenia cutoff values.
ARTICLE | doi:10.20944/preprints202309.1606.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Vitamin D; Vitamin D receptor (VDR); Sirtuin; Sarcopenia; Muscle atrophy; Mitochondrial Biogenesis; Oxidative Phosphorylation (OXPHOS)
Online: 25 September 2023 (12:55:47 CEST)
Age-related declines in vitamin D receptor (VDR) expression have been implicated in the onset of sarcopenia. The increased expression of VDR in muscle is known to increase muscle mass, whereas VDR knockout in the muscle decreases muscle mass in rats. Similar to VDR, the age-related decline in protein deacetylase sirtuin (SIRT) expression is linked to the development of sarcopenia and age-related muscle dysfunction. This study aimed to investigate whether the VDR agonist 1,25-dihydroxyvitamin D3 (1,25VD3) exerts beneficial effects on muscles through interactions with sirtuins and, if so, the underlying molecular mechanisms. 1,25VD3 treatment increases the expression of VDR, SIRT1, and SIRT3 in C2C12 myotubes. Additionally, it stimulates the differentiation of C2C12 myoblasts into myotubes. Furthermore, 1,25VD3 significantly enhanced the expression of key myogenic markers, including myosin heavy chain (MyHC) proteins (MyHC I and II), MyoD, and MyoG, and increased the phosphorylation of AMPK and AKT. Conversely, VDR knockdown in myoblasts induces myotube atrophy by downregulating SIRT1 and SIRT3 expression. Furthermore, 1,25VD3 ameliorated muscle atrophy and apoptosis induced by IFN-γ/TNF-α co-treatment to C2C12 myotube. Moreover, 1,25VD3 downregulated the increased expression of muscle atrophy-associated proteins, including FoxO3a, MAFbx, and MuRF1 in IFN-γ/TNF-α induced atrophy model. Importantly, IFN-γ/TNF-α significantly reduced the mtDNA copy number in C2C12 myotube, whereas the presence of 1,25VD3 effectively prevented this decrease. These results indirectly suggest that 1,25VD3 has the potential to develop as a therapeutic or preventive agent for age-mediated muscle atrophy by enhancing the VDR/SIRT1/SIRT3 axis and inhibiting the FoxO3-mediated atrophy pathway.
REVIEW | doi:10.20944/preprints202112.0017.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: frailty; muscle volume; nutritional status; prognostic factor; sarcopenia; skeletal muscle mass; stroke; temporal muscle thickness.
Online: 1 December 2021 (13:12:03 CET)
Background: Evaluating muscle mass and function among stroke patients is important. However, evaluating muscle volume and function is not easy due to the disturbance of consciousness and paresis. Temporal muscle thickness (TMT) has been introduced as a novel surrogate marker for muscle mass, function, and nutritional status. We herein performed a narrative literature review on temporal muscle and stroke to understand the current meaning of the TMT in the clinical stroke practice. Methods: The search was performed in PubMed, last updated in October 2021. Report on temporal muscle morphomics and stroke-related diseases or clinical entities were collected. Results: Four studies reported on TMT and subarachnoid hemorrhage, 2 intracerebral hemorrhage, 2 ischemic stroke, 2 standard TMT values, and 2 nutritional status. TMT was reported as a prognostic factor for several diseases, surrogate markers for skeletal muscle mass, and an indicator of nutritional status. Computed tomography, magnetic resonance imaging, and ultrasonography were used to measure TMT. Conclusions: TMT is gradually used as a prognostic factor of stroke or surrogate marker for skeletal muscle mass and nutritional status. Establishing standard methods to measure TMT and large prospective studies to investigate the further relationship between TMT and diseases are needed.
REVIEW | doi:10.20944/preprints202101.0580.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: stroke; sarcopenia; computed tomography; ultrasound; bioelectrical impedance analysis; muscle; temporal muscle; rectus femoris muscle; diaphragm; calf circumference
Online: 28 January 2021 (12:31:09 CET)
Muscle mass at admission is important to survive stroke, and stroke-induced sarcopenia is a serious problem because of its poor prognosis. Muscle mass measurement and monitoring are essential for appropriate re-habilitation and nutrition management. Several methods are used to assess skeletal muscle mass in stroke, such as computed tomography (CT), ultrasonography, bioelectrical impedance analysis, dual-energy X-ray absorptiometry, biomarkers, and anthropometrics. In stroke, a head CT is used to estimate muscle mass by measuring the temporal muscle. However, it is mostly retrospectively conducted due to radiation exposure. After stroke, limb muscle atrophy and diaphragm dysfunction are observed using ultrasound. However, ultrasound requires an understanding of the methods and skill. A bioelectrical impedance analysis can be used to assess muscle mass in patients after a stroke unless they have dynamic fluid changes. Dual-energy X-ray absorptiometry is used for follow-up after hospital discharge. Urinary titin N-fragment and serum C-terminal agrin fragment reflect muscle atrophy after stroke. Anthropometrics may be useful with limited resources. We summarized the features of each measurement and proved the recent evidence to properly measure and monitor skeletal muscle mass after stroke.
REVIEW | doi:10.20944/preprints201911.0013.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: lung transplantation; body mass index; nutrition; body composition; lean body mass; muscle mass; leptin; sarcopenia; creatinine-height index
Online: 1 November 2019 (13:02:51 CET)
Lung transplantation offers patients with end stage lung disease an opportunity for a better quality of life, but with limited organ availability it is paramount that selected patients have the best opportunity for successful outcomes. Nutrition plays a central role in post-surgical outcomes and historically, body mass index (BMI) has been used as the de facto method of assessing a lung transplant candidate’s nutritional status. Here we review the historical origins of BMI in lung transplantation, summarize the current BMI literature, and review studies of alternative/complementary body composition assessment tools, including lean psoas area, creatinine-height index, leptin, and dual x-ray absorptometry. These body composition measures quantify lean body mass versus fat mass and may provide a more comprehensive analysis of a patient’s nutritional state than BMI alone.
REVIEW | doi:10.20944/preprints202306.2123.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: sarcopenia; frailty; comorbidity; diabetes; chronic kidney disease (CKD); heart failure; dementia; vitamin D; oral nutritional supplement (ONS); elderly people
Online: 29 June 2023 (13:14:19 CEST)
Many countries are facing the advent of super-aging societies, where sarcopenia and frailty will become emerging problems. Elderly people suffer from various diseases, such as diabetes, heart failure, chronic kidney disease and dementia. The prevalence of comorbidities is a major problem in countries with aged populations. Underlying diseases, such as diabetes, heart failure, chronic kidney disease and also dementia are associated with sarcopenia and frailty, and they are frequent causes of falls, fractures, and a decline in activities of daily living. Fractures in the elderly people are associated with bone fragility, which is influenced by diabetes and chronic kidney disease. Nutritional support for chronic disease patients and sarcopenic individuals with adequate energy and protein intake, vitamin D supplementation, blood-glucose-level management for individuals with diabetes, obesity prevention, nutritional education for healthy individuals, and the enlightenment of society could be crucial to solving the problems in super-aging societies.
REVIEW | doi:10.20944/preprints202306.2095.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: sarcopenia; frailty; comorbidity; diabetes; chronic kidney disease (CKD); heart failure; dementia; vitamin D; oral nutritional supplement (ONS); elderly people
Online: 29 June 2023 (11:05:54 CEST)
Many countries are facing the advent of super-aging societies, where sarcopenia and frailty will become emerging problems. Elderly people suffer from various diseases, such as diabetes, heart failure, chronic kidney disease and dementia. The prevalence of comorbidities is a major problem in countries with aged populations. Underlying diseases, such as diabetes, heart failure, chronic kidney disease and also dementia are associated with sarcopenia and frailty, and they are frequent causes of falls, fractures, and a decline in ADL. Fractures in the elderly people are associated with bone fragility. Diabetes and chronic kidney disease are associated with bone fragility. Nutritional support for chronic disease patients and sarcopenic individuals with adequate energy and protein intake, vitamin D supplementation, blood-glucose-level management for individuals with diabetes, obesity prevention, nutritional education for healthy individuals, and the enlightenment of society could be crucial to solving the problems in super-aging societies.
ARTICLE | doi:10.20944/preprints202309.1752.v1
Subject: Medicine And Pharmacology, Gastroenterology And Hepatology Keywords: Hepatocellular carcinoma; Transarterial radioembolization; Yttrium-90; Locoregional treatment; Portal vein tumor thrombosis; Overall survival; Progression-free survival; Skeletal muscle mass; Sarcopenia; Body mass index.
Online: 26 September 2023 (08:22:48 CEST)
Trans-arterial radioembolization (TARE) is a form of radiation therapy performed for hepatocellular carcinoma (HCC) via selective intra-arterial injection of Yttrium-90 loaded microspheres. This was a multicenter retrospective study of consecutive patients with HCC who underwent TARE between July 2009 and May 2019. Using pre-treatment computed tomography imaging, the total cross-sectional area (cm2) of the abdominal skeletal muscle at the third lumbar vertebra was measured. The skeletal muscle index (SMI) was calculated by normalizing the muscle area to patient height. In total, 347 patients (median age, 65 years; 284 male) were included in the study. A total of 108 (31.1%) patients had portal vein tumor thrombus (PVTT) and 126 (36.3%) were classified as sarcopenic. The median overall survival (OS) was 28.1 months (95% CI, 24.8-35.7) and median progression-free survival was 8.0 months (95% CI, 6.4-9.4). Multivariate Cox regression analysis revealed that sarcopenia (hazard ratio [HR], 1.36; 95% CI, 1.00-1.85, p = 0.05), PVTT (HR, 1.82; 95% CI, 1.33-2.49, p < 0.01), alpha-fetoprotein (AFP) (≥200 ng/mL) (HR 1.41; 95% CI, 1.04-1.92, p = 0.03), and albumin-bilirubin grade (2-3) (HR 1.74; 95% CI, 1.24-2.43, p < 0.01) were independently associated with poor OS. TARE provided favorable long-term outcomes for patients with advanced HCC. Pre-treatment sarcopenia independently associated with survival, suggesting its utility as a surrogate biomarker for identifying TARE candidates.