Synergistic effects of diabetes and sarcopenic obesity on cardiovascular disease risk in middle-aged and elderly Chinese adults: a large-scale prospective cohort study

Diabetes mellitus and sarcopenic obesity are increasingly prevalent conditions in aging populations, both independently associated with elevated cardiovascular disease risk. However, their synergistic effects on cardiovascular outcomes in Asian populations remain poorly understood. This study aimed to evaluate the individual and combined impacts of diabetes and sarcopenic obesity on cardiovascular disease risk in middle-aged and elderly Chinese adults. We conducted a prospective cohort analysis using data from the China Health and Retirement Longitudinal Study (CHARLS). A total of 10,478 participants without baseline cardiovascular disease (5,122 men and 5,356 women; mean age 58.77 ± 9.24 years) were followed for 9 years (2011–2020). Participants were categorized into four groups: neither condition, diabetes alone, sarcopenic obesity alone, and both conditions. Cardiovascular disease events were identified through physician-diagnosed reports. Cox proportional hazards models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs), adjusting for demographic, lifestyle, and clinical covariates. During 9 years of follow-up, 2,443 participants (23.3%) developed cardiovascular disease. Compared to participants with neither condition, the multivariable-adjusted HRs for cardiovascular disease were 1.11 (95% CI: 0.96–1.29) for diabetes alone, 1.05 (95% CI: 0.94–1.17) for sarcopenic obesity alone, and 1.34 (95% CI: 1.10–1.63, P = 0.004) for both conditions combined. The cumulative incidence of cardiovascular disease was significantly higher in the combined group (39.0%) compared to the control group (24.4%), diabetes alone (31.6%), and sarcopenic obesity alone (27.3%). Similar patterns were observed for stroke and cardiac events separately. The coexistence of diabetes and sarcopenic obesity synergistically increases cardiovascular disease risk beyond the effects of either condition alone in Chinese adults. These findings highlight the importance of comprehensive screening and integrated management strategies for individuals with both conditions to prevent cardiovascular complications.