Background: To investigate the cross-sectional and longitudinal associations between depressive symptoms and the prevalence of frailty and its components in a nationally representative sample of middle-aged and older Chinese adults.
Method: The China Health and Retirement Longitudinal Study (CHARLS) provided data on 17,104 adults aged ≥ 45 years. Every two years, face-to-face, computer-aided personal interviews (CAPI), and structured questionnaires were used to follow up with the respondents. The Chinese version of the Center for Epidemiologic Studies-Depression Scale (CES-D) was used to evaluate depressive symptoms, and the Fried criteria were used to measure frailty. The odds ratio (OR) and 95% confidence interval (CI) for the cross-sectional connections among depressive symptoms and frailty and its components in the individuals at baseline were analyzed using logistic regression. A Cox proportional hazards analysis was performed using the hazard ratio (HR) and 95% confidence interval for the prospective connection between baseline depressive symptoms and frailty and its component in the participants without frailty at baseline.
Results: At baseline, 11.62% of participants had frailty, and 57.92% had depressive symptoms. In the cross-sectional analysis, depressive symptoms (OR = 5.222, 95%CI 3.665-7.442) were associated with frailty. In the longitudinal analysis, after adjusting for the full set of covariates among participants free of baseline frailty, depressive symptoms were significantly associated with incident frailty during the short term [HR = 2.193 (1.324-3.631)] and the long term [HR = 1.926 (1.021-3.632)]. Meanwhile, depressive symptoms were associated with an increased risk of weakness [HR = 1.990 (1.250-3.166)], slowness [HR = 1.395 (1.044-1.865)], and exhaustion [HR = 2.827 (2.150-3.719)] onset during the short-term. Depressive symptoms were associated with an increased risk of exhaustion [HR = 2.869 (2.004-4.109)] onset during the long-term.
Conclusion: Among middle-aged and older adults, depressive symptoms could predict frailty during 2 years of follow-up and 4 years of follow-up. When considering potential confounding factors, depressive symptoms were considered a predictor of weakness, slowness, and exhaustion. Interventions aimed at preventing depressive symptoms may be beneficial in reducing frailty and its components.
Keywords: cohort study; depressive symptoms; frailty; middle-aged and elderly.