Metabolic syndrome predicts incident disability and functional decline among Chinese older adults: results from the China Health and Retirement Longitudinal Study

Aims To investigate the longitudinal association of metabolic syndrome (MetS) and its components with disability outcomes. Methods A total of 5875 participants aged 60 and above completed the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). MetS at baseline was measured by the National Cholesterol Education Program Adult Treatment Panel III criteria. Logistic regressions were conducted to analyze the associations between baseline MetS and incident disability, measured as the onset of limitations regarding instrumental activities of daily living (IADL) and activities of daily living (ADL) 4 years later. Linear regression was adopted to analyze the longitudinal impact of baseline MetS on the number of IADL and ADL limitations in 2015. A comprehensive list of baseline covariates was adjusted in all regression analyses. Results Baseline MetS was related to increased odds of incident IADL disability (OR = 1.28, 95% CI 1.05–1.55) and incident ADL disability (OR = 1.27, 95% CI 1.05–1.53) among disability-free participants at baseline. Baseline MetS was also associated with an increase in the number of IADL (beta = 0.15, 95% CI 0.07–0.23) and ADL limitations (beta = 0.10, 95% CI 0.01–0.18), while adjusting for baseline functional performance. Significant MetS component predictors of disability outcomes include abdominal obesity, high blood pressure, and a low level of high-density lipoprotein cholesterol. Conclusions Our findings suggest an increased risk of incident disability and deteriorated functional performance over 4 years, associated with the presence of MetS and its components.