Colon Capsule Endoscopy–Measured Colonic Transit Time Is Associated with Frailty in Older Adults

Background and Objectives: Although the association between frailty and constipation in older adults has attracted attention, evidence regarding the relationship between the Clinical Frailty Scale (CFS) and colonic transit time (CTT) remains limited. This retrospective study investigated their association using colon capsule endoscopy (CCE). Patients and Methods: We enrolled 124 older adults (64 men and 60 women) aged ≥ 65 (mean age, 74.6 ± 5.6) years who underwent CCE for colorectal polyp screening at the Aishinkai Nakae Hospital (Japan) between January 2014 and July 2024. CTT was measured at the time of CCE. Frailty was assessed using the CFS (Japanese version). Participants were classified into Robust (CFS 1–2; n=73) and Non-robust (CFS 3–7; n=51) groups. The independent association between CFS score and CTT was examined using multivariate linear regression analysis, with patient background factors as covariates (age, sex, body mass index, type 2 diabetes mellitus, laxative use, anticholinergic drug use, psychotropic drug use, hypothyroidism, smoking history, and history of abdominal surgery). Results: CTT was significantly longer in the Non-robust group than that in the Robust group (203±121 vs. 158±100 min). Sensitivity analysis using the Mann–Whitney U test also demonstrated a significant difference (U=1441.5). A stepwise prolongation of CTT was observed with increasing CFS scores (Spearman’s ρ=0.232; P=0.009). Sex-stratified analysis revealed that CTT prolongation was significant in women (200±114 vs. 155±104 min). In a multivariate linear regression analysis using CFS as a continuous variable and adjusting for 11 covariates, CFS score (β = 36.6; 95% CI: 17.3–56.0; P < 0.001) and female sex (β = 48.5; 95% CI: 9.1–88.0; P = 0.016) were identified as independent factors associated with CTT prolongation (R² = 0.164; P = 0.035). Conclusions: Frailty progression is associated with delayed colonic transit in older adults, particularly in women. CCE may represent a novel and clinically valuable modality for assessing frailty-related bowel dysfunction in older adults.