“…We included the following baseline variables as covariates: age (45–59, 60 + years), sex (male, female), self-rated health (poor, fair, good) [ 30 ], education (no formal education, primary school, middle school or above), body mass index (BMI) (underweight: < 18.5 kg/m 2 , normal: 18.5–22.9 kg/m 2 , overweight: 23.0–27.4 kg/m 2 , obesity: ≥ 27.5 kg/m 2 ), [ 31 ] occupation (agricultural, non-agricultural, unemployed/retired), ever smoking (no, yes), alcohol drinking (no, yes), sleep duration (< 7 h/day, 7–8 h/day, > 8 h/day), marital status (married/cohabitation, single: divorced, separated, widowed, or never married), annual household expenditure (≤ 2800 yuan, 2801–4846 yuan, 4847–8325 yuan, > 8325 yuan), social participation (whether the respondent participated in any social activities), location of residence (rural, urban) and public health insurance status (no, yes).…”