Association between chronic pain and frailty among Chinese adults aged ≥ 60 years: a cross-sectional study

Chronic pain may elevate the risk of frailty in older adults, but its characteristics in age and sex remains unclear, and the mediators of this relationship are largely unknown. We analyzed cross-sectional data from the Comprehensive Geriatric Assessment Database of Tongji Hospital and explored the relationship between chronic pain and frailty in adults aged ≥ 60 years through multiple linear regression, binary logistic regression, restricted cubic spline regression and mediation analysis. Covariates comprised age, sex, education, marital status, smoking, drinking, body mass index, hypertension, diabetes, cardiovascular disease, and stroke, while sleep quality, activities of daily living, anxiety, and depression were regarded as potential mediators. Among 1951 adults aged ≥ 60 years (mean age 77.86 ± 9.74 years, 45.7% female), the prevalence of frailty increased with chronic pain severity, with the odds of frailty being 1.28 (95% CI 1.06-1.54), 1.35 (95% CI 1.18-1.55), 1.39 (95% CI 1.19-1.61), and 1.71 (95% CI 1.39-2.11) times higher among participants aged 60-69, 70-79, 80-89, and ≥ 90 years, respectively, compared to those without pain. Additionally, the increase in frailty prevalence with rising pain severity was more pronounced in females than in males. Mediation analysis suggested that poor sleep quality (28.63%), depression (27.64%), and anxiety (43.73%) partially explained the association between chronic pain and frailty. These findings underscore the importance of addressing chronic pain and its associated factors (such as poor sleep quality, depression, and anxiety) in interventions aimed at managing frailty, particularly among females.