Impact of physical inactivity and excess body weight on the development of cardiometabolic multimorbidity in Chinese adults: an 8-year population-based cohort study from 2011 to 2018

Background To examine the independent effects of physical inactivity and excess body weight on cardiometabolic multimorbidity (CMM) development and progression in Chinese adults. Methods We analyzed data from 9,916 adults aged ≥ 45 years in the China Health and Retirement Longitudinal Study (2011–2018). Physical inactivity (not meeting WHO activity guidelines) and excess body weight (body mass index ≥ 25 kg/m 2 ) were assessed at baseline. CMM was defined as the presence of ≥ 2 of these chronic cardiovascular and metabolic diseases: hypertension, dyslipidaemia, type 2 diabetes, cardiovascular diseases, and stroke. Using Poisson-distributed Generalized Linear Models, we estimated their effects on new-onset CMM, progression to complex CMM (≥ 3 conditions), and worsening of existing CMM (new conditions added). Results Over 8 years, 25% of healthy adults developed CMM, and 28% of those with existing CMM experienced worsening. Physical inactivity independently increased the risks of new-onset CMM (risk ratio [RR] = 1.25, 95% confidence interval [CI]: 1.14–1.39), complex CMM (RR = 1.61, CI: 1.35–1.93), and worsening CMM (RR = 1.21, CI: 1.03–1.43). Excess body weight had stronger effects on new CMM (RR = 1.74, CI: 1.61–1.87), complex CMM (RR = 2.13, CI: 1.85–2.45), and worsening CMM (RR = 1.38, CI: 1.21–1.58). Conclusions Both physical inactivity and excess weight independently drive CMM progression in Chinese adults. Population-level interventions promoting active lifestyles and healthy weight are urgently needed to mitigate CMM burden.