Sleep Quality and Quality of Life in Adults with Type 2 Diabetes in Bangladesh

1. Introduction

Diabetes mellitus is one of the most prevalent non-communicable diseases (NCDs) globally, with type 2 diabetes (T2D) accounting for 85-95% of all diabetes cases. In developed countries, T2D represents over 90% of diabetes cases [1]. The global prevalence of diabetes is estimated to be over 537 million adults aged 20-79 years, with projections to exceed 700 million by 2045 [2]. T2D is associated with numerous complications, including cardiovascular disease, kidney disease, neuropathy, vision loss, and lower extremity amputation, all of which significantly contribute to morbidity and mortality worldwide [3]. These complications often lead to an increased burden on healthcare systems and the economy, with substantial indirect costs due to premature mortality and lost productivity [4].

In Bangladesh, the prevalence of NCDs, including T2D, has sharply increased in recent years, making it a critical public health issue. While the estimated prevalence of diabetes among adults was 9.7% in 2011, it is estimated to be 13.7 million by 2045 [5]. It is estimated that 12 million people over the age of 30 are at risk of developing T2D [6]. Despite advancements in diagnostic and treatment strategies, the burden of the disease continues to have significant consequences for patients, including impaired well-being and quality of life [7].

2. Materials and Methods

2.1. Study Design and Settings

A cross sectional survey was undertaken to assess sleep quality and quality of life in 180 adults with type-2 diabetes mellitus. The patients were recruited from Mirpur National Health Care network, a primary health care centre for diabetic patients in Dhaka, Bangladesh which is affiliated with the Bangladesh Institute of Research and Rehabilitation for Diabetes, Endocrine and Metabolic Disorder (BIRDEM).

2.2. Study Sampling and Data Collection

A semi-structured questionnaire was used for data collection. A total of 180 diabetic patients who were attending the outpatient department of National Health Care Network were randomly selected and interviewed. All of them were willing to participate in this study. The two inclusion criteria of study participants were to be aged at least 25 and above and duration of diabetes (>1 year). We excluded the diabetes cases with pregnancy, inability to communicate and who were unwilling to participate.

2.3. Evaluation of Quality of Life

The tool used for evaluation of quality of life was the questionnaire, the Short Form 36 Version 2 (SF-36 V2TM version 2) [16]. The SF-36 contains 36 items evaluating 8 dimensions of health: physical functioning, role limitations due to physical problems, bodily pain, general health perceptions, vitality, social functioning, role limitations due to emotional problems, and mental health. Each dimension is scored on a 0 to 100 scale, with higher scores indicating better functioning. In addition, the SF-36 includes 2 composite summary scores: the physical component score (PCS) and the mental component score (MCS). The PCS and MCS are standardized to a mean (SD) of 50, with lower scores indicating more significant dysfunction [17].

2.4. Measurement of Sleep Quality

Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI) [18]. The PSQI assesses quality of sleep during the past month and contains 7 component scales: sleep quality, sleep latency, sleep duration, sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. Each component is scored from 0 to 3, yielding a global PSQI score ranging from 0 to 21, with higher scores indicating worse sleep quality. The PSQI was utilized for several goals: (1) to provide a reliable, valid, and standardized measure of sleep quality; (2) to discriminate between “good” and “poor” sleepers; (3) to provide an index that is easy for subjects to use and for clinicians and researchers to interpret; and (4) to provide a brief, clinically useful assessment of a variety of sleep disturbances that might affect sleep quality [19].

2.5. Data Analysis

After completion of data collection, data were stored and quality control check was performed. Descriptive statistics including means, medians, standard deviations, ranges for continuous data and frequencies and proportion for categorical data was calculated. For inferential statistics, mainly one way ANOVA, t test, chi-square test and Pearson’s correlation were used. In all the tests, p˂0.05 was considered to be statistically significant.

3. Results

3.1. Socio-Demographic Characteristics of Patients

Highest proportion of the respondent (48.9%) was in ≥ 50 years age group followed by 40 – 49 years age group (30%). Mean (SD) age of the respondents were 48.31 (9.02) years. Majority proportion of the respondents were females (65%) and the rest were males. Most of the respondents (79.4%) were married. Rest 20.6% were categorized as others which included unmarried, divorced, widow/ widower and separated. Major proportion of respondents (43.3%) were in the educational level of S.S.C and H.S.C, up to primary level there were 25% patients, the rest were graduates and above. Among 180 respondents 48.3% were housewives, service holder 24.5%. and lowest group were day laborer (3.3%). The distribution of number of family members of respondents showed majority (67.2%) had <5 members in their family and 7.8% had more than 8 members in their family. Average family size was 5.1. Among the total respondents 83.3% were from urban areas and 15% from rural areas.

Table 1. Socio-demographic characteristics of the type 2 diabetic patients.

Characteristics	Frequency	Percent
Religion
Islam Hindu	158 22	87.8 12.2
Marital status
Married Others	143 37	79.4 20.6
Education
Up to Primary S.S.C and H.S.C Graduates and above	45 78 57	25.0 43.3 31.7
Occupation
Service Business Housewife Retired Day laborer	44 23 87 20 6	24.5 12.8 48.3 11.1 3.3
Monthly family income
<20000 20000 to 29000 30000 to 39000 40000 to 49000 50000 to 59000 ≥60000	62 13 33 14 22 36	34.4 7.2 18.3 7.8 12.3 20.0
Family size
<5 5 – 6 7 – 8 >8	121 21 24 14	67.2 11.7 13.3 7.8
Ownership of house
No Yes	96 84	53.3 46.7
Type of house
Pacca building Semi- pacca building	155 25	86.1 13.9
Area of residence
Urban Rural	153 27	85.0 15.0

Table 1. Socio-demographic characteristics of the type 2 diabetic patients.

Characteristics	Frequency	Percent
Religion
Islam Hindu	158 22	87.8 12.2
Marital status
Married Others	143 37	79.4 20.6
Education
Up to Primary S.S.C and H.S.C Graduates and above	45 78 57	25.0 43.3 31.7
Occupation
Service Business Housewife Retired Day laborer	44 23 87 20 6	24.5 12.8 48.3 11.1 3.3
Monthly family income
<20000 20000 to 29000 30000 to 39000 40000 to 49000 50000 to 59000 ≥60000	62 13 33 14 22 36	34.4 7.2 18.3 7.8 12.3 20.0
Family size
<5 5 – 6 7 – 8 >8	121 21 24 14	67.2 11.7 13.3 7.8
Ownership of house
No Yes	96 84	53.3 46.7
Type of house
Pacca building Semi- pacca building	155 25	86.1 13.9
Area of residence
Urban Rural	153 27	85.0 15.0

3.2. Complications of Diabetes Among Participants

Among 180 respondents 111(61.7%) were suffering from different types of diabetic complications. Hypertension was more common 94(52.2%). Distribution of complications is shown in Table 2.

Table 2. Complications pattern of patients.

Characteristics	Frequency	Percent
Presence of complications
Yes No	111 69	61.7 38.3
Types of complication
Hypertension	94	52.2
Coronary heart disease	27	15
Urinary infection	5	2.8
Nephropathy	10	5.6
Retinopathy	1	0.6
Cataract	1	0.6
Peripheral neuropathy	5	2.8

Table 2. Complications pattern of patients.

Characteristics	Frequency	Percent
Presence of complications
Yes No	111 69	61.7 38.3
Types of complication
Hypertension	94	52.2
Coronary heart disease	27	15
Urinary infection	5	2.8
Nephropathy	10	5.6
Retinopathy	1	0.6
Cataract	1	0.6
Peripheral neuropathy	5	2.8

3.3. Relationship Among Diabetes Duration, Status, Complications and Sleep Quality

3.3.1. Duration of Diabetes and Sleep Quality Score

Our study participants’ mean (SD) duration of diabetes was 8.48(5.15) years, ranging from . 01-28 years. Mean(SD) of duration of diabetes was 8.48(5.15) years. Day time dysfunction score (r=0.323, p<0.001) had moderate positive correlation with duration of diabetes. Overall sleep quality (r=0.294, p<0.001), subjective sleep quality (r=0.289, p<0.001), sleep latency (r=0.223, p<0.05) and sleep duration (r=0.214, p<0.05) were also correlated with duration of diabetes. With the increase in duration of diabetes sleep quality score increased. We further categorized the duration of diabetes into <5, 5 to 9, 10 to 14 and ≥15 years. Duration of diabetes had significant association with overall sleep quality (p=0.001), subjective sleep quality (p=0.001), sleep latency (p=0.019), sleep disturbance (p=0.039) and day time dysfunction ( p<0.001). Post hoc test revealed that sleep quality score was significantly different in all domains and over all sleep quality in >15 years duration of diabetes respondents.

Table 3. Duration of diabetes and sleep quality score.

Characteristics	Diabetes duration ( years)	N	Mean score	SD	F	P-value	r©	P-value
Overall sleep quality	<5 5 – 9 10 – 14 ≥15	63 59 33 25	6.20 7.32 8.30 8.60	2.75 3.10 2.73 3.11	5.774	0.001	0.294	<0.001
Subjective sleep quality	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.40 1.57 1.78 1.96	0.58 0.68 0.69 0.78	5.432	0.001	0.289	<0.001
Sleep latency	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.39 1.72 1.84 1.92	0.81 0.80 0.93 0.95	3.418	0.019	0.223	0.003
Sleep duration	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.29 1.42 1.63 1.75	0.84 0.72 0.96 1.10	2.844	0.039	0.214	0.004
Habitual sleep efficiencies	<5 5 – 9 10 – 14 ≥15	63 59 33 25	0.79 0.96 1.27 1.24	0.96 1.11 0.98 1.23	1.955	0.122	0.184	0.013
Sleep disturbance	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.00 1.00 1.06 1.08	0.00 0.00 0.24 0.28	3.034	0.031	0.199	0.008
Use of sleep medication	<5 5 – 9 10 – 14 ≥15	63 59 33 25	0.73 0.98 1.12 1.12	0.95 1.09 0.89 0.97	1.615	0.188	0.134	0.073
Day time dysfunction	<5 5 – 9 10 – 14 ≥15	63 59 33 25	0.88 1.06 1.22 1.28	0.47 0.36 0.41 0.54	6.497	<0.001	0.323	<0.001

Table 3. Duration of diabetes and sleep quality score.

Characteristics	Diabetes duration ( years)	N	Mean score	SD	F	P-value	r©	P-value
Overall sleep quality	<5 5 – 9 10 – 14 ≥15	63 59 33 25	6.20 7.32 8.30 8.60	2.75 3.10 2.73 3.11	5.774	0.001	0.294	<0.001
Subjective sleep quality	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.40 1.57 1.78 1.96	0.58 0.68 0.69 0.78	5.432	0.001	0.289	<0.001
Sleep latency	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.39 1.72 1.84 1.92	0.81 0.80 0.93 0.95	3.418	0.019	0.223	0.003
Sleep duration	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.29 1.42 1.63 1.75	0.84 0.72 0.96 1.10	2.844	0.039	0.214	0.004
Habitual sleep efficiencies	<5 5 – 9 10 – 14 ≥15	63 59 33 25	0.79 0.96 1.27 1.24	0.96 1.11 0.98 1.23	1.955	0.122	0.184	0.013
Sleep disturbance	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1.00 1.00 1.06 1.08	0.00 0.00 0.24 0.28	3.034	0.031	0.199	0.008
Use of sleep medication	<5 5 – 9 10 – 14 ≥15	63 59 33 25	0.73 0.98 1.12 1.12	0.95 1.09 0.89 0.97	1.615	0.188	0.134	0.073
Day time dysfunction	<5 5 – 9 10 – 14 ≥15	63 59 33 25	0.88 1.06 1.22 1.28	0.47 0.36 0.41 0.54	6.497	<0.001	0.323	<0.001

3.3.2. Glycemic Control and Sleep Quality Score

To understand the glycemic xcontrol, we collected data on HbA1c status of the participants. Correlation co-efficient between sleep quality score and HbA1c were estimated. Overall sleep quality (r=0.190, p>0.05) and sleep disturbance (r=0.183, p<0.05) had weaker positive correlation with the glycemic control. Subjective sleep quality (r=0.759, P<0.001), sleep latency (0.832, P<0.001), sleep duration (r=0.680, P<0.001), habitual sleep efficiency (r=0.688, p<0.001), use of sleep medication (r=0.796, P<0.001), and time dysfunction (r=5.70, P<0.001) had strong significant correlation with glycemic control. We also categorized HbA1c data into controlled and uncontrolled group. t test revealed significant relationship of sleep quality score in no domains with glycemic control status.

Table 4. Correlation between glycemic control and sleep quality score.

Characteristics	Glycemic level	N	Mean score	SD	t	P-value	r©	P-value
Overall sleep quality	Controlled Uncontrolled	25 38	7.48 8.68	2.85 3.23	-1.511	0.136	0.190	0.136
Subjective sleep quality	Controlled Uncontrolled	25 38	1.56 1.84	0.71 0.82	-1.403	0.166	0.759	<0.001
Sleep latency	Controlled Uncontrolled	25 38	1.68 2.02	0.90 0.92	-1.479	0.144	0.832	<0.001
Sleep duration	Controlled Uncontrolled	25 38	1.44 1.65	1.04 0.96	-0.848	0.400	0.680	<0.001
Habitual sleep efficiencies	Controlled Uncontrolled	25 38	1.08 1.34	1.12 1.24	-0.855	0.396	0.688	<0.001
Sleep disturbance	Controlled Uncontrolled	25 38	1.04 1.02	0.20 0.16	0.298	0.766	0.183	0.014
Use of sleep medication	Controlled Uncontrolled	25 38	1.00 1.18	1.00 0.95	-0.735	0.465	0.796	<0.001
Day time dysfunction	Controlled Uncontrolled	25 38	1.12 1.26	0.44 0.45	-1.253	0.215	0.570	<0.001

© Correlation co-efficient.

Table 4. Correlation between glycemic control and sleep quality score.

Characteristics	Glycemic level	N	Mean score	SD	t	P-value	r©	P-value
Overall sleep quality	Controlled Uncontrolled	25 38	7.48 8.68	2.85 3.23	-1.511	0.136	0.190	0.136
Subjective sleep quality	Controlled Uncontrolled	25 38	1.56 1.84	0.71 0.82	-1.403	0.166	0.759	<0.001
Sleep latency	Controlled Uncontrolled	25 38	1.68 2.02	0.90 0.92	-1.479	0.144	0.832	<0.001
Sleep duration	Controlled Uncontrolled	25 38	1.44 1.65	1.04 0.96	-0.848	0.400	0.680	<0.001
Habitual sleep efficiencies	Controlled Uncontrolled	25 38	1.08 1.34	1.12 1.24	-0.855	0.396	0.688	<0.001
Sleep disturbance	Controlled Uncontrolled	25 38	1.04 1.02	0.20 0.16	0.298	0.766	0.183	0.014
Use of sleep medication	Controlled Uncontrolled	25 38	1.00 1.18	1.00 0.95	-0.735	0.465	0.796	<0.001
Day time dysfunction	Controlled Uncontrolled	25 38	1.12 1.26	0.44 0.45	-1.253	0.215	0.570	<0.001

© Correlation co-efficient.

3.3.3. Complication of Diabetes and Sleep Quality

On an average, sleep quality of the respondents with diabetes complications were higher in overall sleep quality and all domains and the findings were significant in overall sleep quality and all domains (p<0.05) except sleep duration (p=0.072).

Table 5. Complication of diabetes and sleep quality score.

Characteristics	Diabetes complication	N	Mean score	SD	t	P-value
Overall sleep quality	Yes No	111 69	8.09 6.00	3.26 2.19	5.135	<0.001
Subjective sleep quality	Yes No	111 69	1.78 1.31	0.70 0.52	5.033	<0.001
Sleep latency	Yes No	111 69	1.84 1.36	0.90 0.72	3.752	<0.001
Sleep duration	Yes No	111 69	1.52 1.37	0.92 0.83	1.809	0.072
Habitual sleep efficiency	Yes No	111 69	1.15 0.75	1.12 0.92	2.577	0.011
Sleep disturbance	Yes No	111 69	1.03 1.00	0.18 0.00	2.028	0.045
Use of sleep medication	Yes No	111 69	1.09 0.68	1.06 0.81	2.963	0.003
Day time dysfunction	Yes No	111 69	1.17 0.88	0.44 0.43	4.234	<0.001

Table 5. Complication of diabetes and sleep quality score.

Characteristics	Diabetes complication	N	Mean score	SD	t	P-value
Overall sleep quality	Yes No	111 69	8.09 6.00	3.26 2.19	5.135	<0.001
Subjective sleep quality	Yes No	111 69	1.78 1.31	0.70 0.52	5.033	<0.001
Sleep latency	Yes No	111 69	1.84 1.36	0.90 0.72	3.752	<0.001
Sleep duration	Yes No	111 69	1.52 1.37	0.92 0.83	1.809	0.072
Habitual sleep efficiency	Yes No	111 69	1.15 0.75	1.12 0.92	2.577	0.011
Sleep disturbance	Yes No	111 69	1.03 1.00	0.18 0.00	2.028	0.045
Use of sleep medication	Yes No	111 69	1.09 0.68	1.06 0.81	2.963	0.003
Day time dysfunction	Yes No	111 69	1.17 0.88	0.44 0.43	4.234	<0.001

3.4. Relationship Among Diabetes Duration, Status, Complications and Quality of Life

3.4.1. Duration of Diabetes and Quality of Life

One way ANOVA test showed that there were significant association between duration of diabetes with overall quality of life and two domains (p<0.001). On an average, the respondents who were suffering from diabetes ≥15 years had lower score in overall quality of life, physical and mental health. Post Hoc test revealed that there were significant differences between the respondents who suffering from diabetes ≥15 years than other three different duration of diabetic groups

Table 6. Duration of diabetes and quality of life.

Characteristics	Duration of diabetes in years	N	Mean score	SD	F	P-value
Overall quality of life	<5 5 – 9 10 – 14 ≥15	63 59 33 25	2252.30 2177.92 1801.73 1528.60	383.54 401.67 528.46 534.40	20.917	<0.001
Physical health	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1415.24 1329.66 1097.42 927.60	267.43 258.21 347.24 315.40	21.934	<0.001
Mental health	<5 5 – 9 10 – 14 ≥15	63 59 33 25	837.06 848.25 707.30 601.00	145.55 182.38 215.03 232.35	14.308	<0.001

Table 6. Duration of diabetes and quality of life.

Characteristics	Duration of diabetes in years	N	Mean score	SD	F	P-value
Overall quality of life	<5 5 – 9 10 – 14 ≥15	63 59 33 25	2252.30 2177.92 1801.73 1528.60	383.54 401.67 528.46 534.40	20.917	<0.001
Physical health	<5 5 – 9 10 – 14 ≥15	63 59 33 25	1415.24 1329.66 1097.42 927.60	267.43 258.21 347.24 315.40	21.934	<0.001
Mental health	<5 5 – 9 10 – 14 ≥15	63 59 33 25	837.06 848.25 707.30 601.00	145.55 182.38 215.03 232.35	14.308	<0.001

3.4.2. Glycemic Control and Quality of Life

Mean score of quality of life in relation to glycemic control level showed higher in controlled group than the uncontrolled group. There were no significant association between the quality of life and diabetes control level (p>0.05). Correlation co-efficient between glycemic control level and quality of life showed that there were moderate negative significant correlation in overall quality of life (r= -0.509, p<0.001), physical health (r= -0.520, p <0.001) and mental health (r=-0.427, p<0.001).

Table 7. Glycemic control and quality of life.

Characteristics	Glycemic level	N	Mean score	SD	r©	P-value	t	P-value
Overall quality of life	Controlled Un-controlled	25 38	1979.32 1775.18	565.90 568.03	-0.509	<0.001	1.398	0.167
Physical health	Controlled Un-controlled	25 38	1218.00 1088.02	364.94 381.40	-0.520	<0.001	1.346	0.183
Mental health	Controlled Un-controlled	25 38	761.32 687.15	227.09 210.97	-0.427	<0.001	1.324	0.190

© Correlation coefficient.

Table 7. Glycemic control and quality of life.

Characteristics	Glycemic level	N	Mean score	SD	r©	P-value	t	P-value
Overall quality of life	Controlled Un-controlled	25 38	1979.32 1775.18	565.90 568.03	-0.509	<0.001	1.398	0.167
Physical health	Controlled Un-controlled	25 38	1218.00 1088.02	364.94 381.40	-0.520	<0.001	1.346	0.183
Mental health	Controlled Un-controlled	25 38	761.32 687.15	227.09 210.97	-0.427	<0.001	1.324	0.190

© Correlation coefficient.

3.4.3. Diabetic Complications and Quality of Life

Mean scores of quality of life in relation to presence of diabetic complications showed that overall quality of life, physical health, mental health were lower in the respondents suffering from complications than in who were not suffering from complications. Diabetic complications of the patients were significantly related with overall quality of life, physical health and mental health (P<0.01).

Table 8. Presence of diabetic complications and quality of life.

Characteristics	Presence of complications	N	Mean score	SD	t	P-value
Overall quality of life	Yes No	111 69	1860.39 2341.44	506.34 364.07	-7.396	<0.001
Physical health	Yes No	111 69	1138.33 1458.84	325.01 242.38	-7.548	<0.001
Mental health	Yes No	111 69	722.06 882.60	209.47 151.59	-5.949	<0.001

Table 8. Presence of diabetic complications and quality of life.

Characteristics	Presence of complications	N	Mean score	SD	t	P-value
Overall quality of life	Yes No	111 69	1860.39 2341.44	506.34 364.07	-7.396	<0.001
Physical health	Yes No	111 69	1138.33 1458.84	325.01 242.38	-7.548	<0.001
Mental health	Yes No	111 69	722.06 882.60	209.47 151.59	-5.949	<0.001

3.5. Relationship between Sleep Quality Score and Quality Of Life

Sleep quality and quality of life of the respondents were assessed by the Pittsburgh Sleep Quality Index and SF-36v2TM respectively.

Sleep quality score in overall sleep quality and all domains were inversely correlated with overall quality of life, physical and mental health score. There were strong significant correlation of overall sleep quality (r= -0.530, p<0.001), subjective sleep quality(r= -0.539, p< 0.001) and day time dysfunction (r= -0.529, p<0.001) with overall quality of life. Sleep latency (r= -0.462, p<0.001) and sleep duration (r= -0.322, p<0.001) moderately correlated with overall quality of life score. Overall sleep quality (r= -0.540, <0.001) and subjective sleep quality (r= -0.535, p<0.001) had strong correlation with physical health. Others domain of sleep quality had significant weaker correlation with the physical health. Only day time dysfunction (r= -0.511, p<0.001) had strong correlation with mental health. Sleep quality score in sleep disturbance had poor correlation with overall quality of life (r= -0.180, p=0.015), physical health (r= -0.186, p= 0.012) and mental health (r= -0.148, p=0.048).

Table 9. Correlation between sleep quality score and quality of life.

Sleep quality	Quality of life
	Overall		Physical health		Mental health
	r©	P-value	r©	P-value	r©	P-value
Overall quality of sleep	-0.530	<0.001	-0.540	<0.001	-0.447	<0.001
Subjective sleep quality	-0.539	<0.001	-0.535	<0.001	-0.474	<0.001
Sleep latency	-0.462	<0.001	-0.472	<0.001	-0.387	<0.001
Sleep duration	-0.322	<0.001	-0.329	<0.001	-0.270	<0.001
Habitual sleep efficiency	-0.281	<0.001	-0.288	<0.001	-0.234	0.002
Sleep disturbance	-0.180	0.015	-0.186	0.012	-0.148	0.048
Use of sleep medication	-0.284	<0.001	-0.312	<0.001	-0.201	0.007
Day time dysfunction	-0.529	<0.001	-0.499	<0.001	-0.511	<0.001

© Correlation co-efficient.

Table 9. Correlation between sleep quality score and quality of life.

Sleep quality	Quality of life
	Overall		Physical health		Mental health
	r©	P-value	r©	P-value	r©	P-value
Overall quality of sleep	-0.530	<0.001	-0.540	<0.001	-0.447	<0.001
Subjective sleep quality	-0.539	<0.001	-0.535	<0.001	-0.474	<0.001
Sleep latency	-0.462	<0.001	-0.472	<0.001	-0.387	<0.001
Sleep duration	-0.322	<0.001	-0.329	<0.001	-0.270	<0.001
Habitual sleep efficiency	-0.281	<0.001	-0.288	<0.001	-0.234	0.002
Sleep disturbance	-0.180	0.015	-0.186	0.012	-0.148	0.048
Use of sleep medication	-0.284	<0.001	-0.312	<0.001	-0.201	0.007
Day time dysfunction	-0.529	<0.001	-0.499	<0.001	-0.511	<0.001

© Correlation co-efficient.

Overall sleep quality was categorized into two groups good sleepers (score ≤5) and poor sleepers (score >5). Relationship between the sleep quality with the overall quality of life, physical health and mental health was significant (p>0.001). Average score in overall quality of life, physical and mental health domains were lower in poor sleeper than good sleeper.

Table 10. Overall sleep quality and quality of life.

Characteristics	Sleep quality	N	Mean score	SD	t	P-value
Overall quality of life	Poor sleeper Good sleeper	117 63	1905.48 2303.52	541.17 326.29	6.147	<0.001
Physical health	Poor sleeper Good sleeper	117 63	1169.31 1431.82	351.58 213.46	6.222	<0.001
Mental health	Poor sleeper Good sleeper	117 63	136.17 871.69	213.33 153.15	4.912	<0.001

Table 10. Overall sleep quality and quality of life.

Characteristics	Sleep quality	N	Mean score	SD	t	P-value
Overall quality of life	Poor sleeper Good sleeper	117 63	1905.48 2303.52	541.17 326.29	6.147	<0.001
Physical health	Poor sleeper Good sleeper	117 63	1169.31 1431.82	351.58 213.46	6.222	<0.001
Mental health	Poor sleeper Good sleeper	117 63	136.17 871.69	213.33 153.15	4.912	<0.001

According to above analysis it was found that more than half of the participants (65%) were “poor sleepers” according to the Pittsburgh Sleep Quality Index. Poor sleep quality was found to be a significant predictor of lower health-related quality of life as indicated by lower scores on both the physical and mental component scores of the Medical Outcomes Study 36-item Short Form health survey (SF-36). Poor sleep quality was also associated with diabetic profile. These results suggest that poor sleep is common in type 2 diabetes and may adversely affect quality of life

4. Discussion

This cross-sectional study aimed to explore the relationship between sleep quality and health-related quality of life (HRQoL) in individuals with type 2 diabetes (T2D). The results revealed that a significant proportion of the participants (65%) were classified as “poor sleepers” according to the Pittsburgh Sleep Quality Index (PSQI). Poor sleep quality was a significant predictor of lower HRQoL, as reflected by lower scores on both the physical (PCS) and mental (MCS) component scores of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) [20]. This finding is consistent with previous research that demonstrates a strong association between poor sleep quality and compromised quality of life in individuals with chronic conditions, particularly T2D [21,22].

In this study, poor sleepers were more likely to be older, female, and have multiple comorbidities, aligning with prior findings that older age and the presence of comorbidities are associated with worse sleep quality in T2D patients [15]. Additionally, poor sleep quality in this cohort was linked with diabetes-related factors, such as the duration of diabetes, number of diabetic complications, and insulin use. These results suggest that individuals with longer diabetes durations and greater disease-related complications are at higher risk of experiencing sleep disturbances, which in turn affect their overall HRQoL. A study by Meier and Sze (2022) also highlighted that prolonged diabetes duration correlates with worsened sleep quality, further substantiating our findings [23].

Our results underscore the importance of recognizing sleep disturbances as a critical factor influencing HRQoL and disease-related quality of life in T2D patients. As indicated by the negative associations between sleep quality and the SF-36 scores, poor sleep appears to impair multiple dimensions of quality of life, including physical health, mental health, and emotional well-being. The interplay between sleep and HRQoL is complex, as poor sleep contributes to both physical and mental health decline, which can exacerbate the challenges faced by individuals with T2D [24].

The study also demonstrated a significant correlation between the duration of diabetes and sleep quality. As the duration of diabetes increased, sleep quality deteriorated. This aligns with findings in other studies that suggest long-term diabetes is associated with disrupted sleep [25]. Additionally, the presence of diabetic complications was significantly related to lower HRQoL scores, particularly in the domains of physical and mental health. These results are consistent with research indicating that diabetic complications, such as neuropathy, cardiovascular disease, and nephropathy, substantially impact the HRQoL of patients [26].

The results further revealed that BMI and glycemic control levels were significant predictors of HRQoL, with higher BMI and poor glycemic control being associated with lower HRQoL scores. This finding is consistent with other studies, which suggest that individuals with uncontrolled diabetes and higher BMI are at an increased risk of experiencing poor quality of life [27,28] Additionally, these factors contribute to the overall burden of diabetes, reinforcing the need for comprehensive management strategies that address both metabolic control and lifestyle factors, including sleep quality [13,29].

This study highlights the need for a holistic approach to managing T2D, where sleep quality is considered a key component of diabetes care. Adequate sleep, along with proper weight management, physical activity, and glycemic control, should be prioritized as part of a healthy lifestyle for T2D patients [30]. Interventions aimed at improving sleep hygiene could significantly enhance the quality of life for individuals with T2D, particularly in settings where sleep disorders are prevalent [31].

Despite the valuable insights provided, this study has some limitations. The cross-sectional design limits the ability to draw causal conclusions, and the sample was drawn from a single hospital, which may not be representative of the broader population. Future studies could benefit from longitudinal designs to further explore the causal relationships between sleep quality, HRQoL, and diabetes-related factors in larger, more diverse populations [32].

In summary, the study reinforces the importance of sleep quality as a critical determinant of HRQoL in individuals with type 2 diabetes [33]. Poor sleep quality is not only a common issue among T2D patients but also a significant factor influencing both physical and mental health outcomes. Addressing sleep disturbances in this population could lead to improved overall health and a better quality of life.

5. Conclusions

The study findings emphasize the importance of screening new patients for sleep problems, making a referral to a sleep medicine specialist if appropriate, and suggesting sleep hygiene strategies as part of diabetes management. The diabetes educator can play a key role in assessing sleep and providing easy to implement interventions to improve sleep hygiene. The study results indicate that having diabetes mellitus is associated with lower health-related quality of life scores. Duration of diabetes, insulin use, and diabetes-related complications are all factors associated with health-related quality of life scores. Strategies should designed to diagnose diabetes early and aggressively manage blood pressure, hyperlipidemia, and albuminuria may not only prevent diabetes-related complications, but may also prevent irreversible deterioration of health-related quality of life in diabetic patients. A comprehensive nationwide study about sleep quality and quality of life of type 2 diabetes patients should be conducted with a view to get national level information which will help to draw an actual picture of these patients and will help on planning for appropriate interventions.