Sarcopenic obesity and the incidence and progression of cardiometabolic multimorbidity: A longitudinal cohort analysis from the CHARLS study

This study aimed to explore the association between sarcopenic obesity (SO) and the incidence and progression of cardiometabolic multimorbidity (CMM) in a Chinese population. This longitudinal cohort study used data from the China Health and Retirement Longitudinal Study (CHARLS). SO was defined as the co-occurrence of sarcopenia and obesity, with sarcopenia assessed by muscle strength or physical performance and obesity assessed by body mass index or waist circumference. Cardiometabolic disease (CMD) included diabetes, heart disease, and stroke. Four distinct health states were defined: no CMD (NCMD), first CMD (FCMD), CMM and death. Cox proportional hazards models were employed to assess the association between sarcopenia/obesity status and incident health state risks, while multi-state Markov models were used to examine its effects on health state transitions and transition probabilities over 5- to 20-year intervals. Compared to obesity alone or sarcopenia alone, SO was associated with significantly higher risks of CMD (HR = 1.91, 95% CI: 1.68–2.18), FCMD (HR = 1.88, 95% CI: 1.64–2.15), and CMM (HR = 3.30, 95% CI: 2.01–5.40), as well as with increased transition risks from NCMD to FCMD (HR = 1.90, 95% CI: 1.66–2.18) and from FCMD to CMM (HR = 1.75, 95% CI: 1.38–2.23). Over a 5- to 20-year period, individuals with SO exhibited the highest probability of progressing to CMM, with rates ranging from 0.04 to 0.36. SO is a significant risk factor for CMM incidence and progression, with greater risk than sarcopenia or obesity alone. It is associated with a higher probability of transition from NCMD to FCMD, to CMM and finally to death. • This longitudinal study first demonstrates that sarcopenic obesity (SO) is significantly associated with the dynamic progression of cardiometabolic multimorbidity (CMM). • SO is a significant risk factor for both the onset and the subsequent progression of CMM. • Compared to sarcopenia or obesity alone, SO is associated with a higher risk of progression from no cardiometabolic disease to first cardiometabolic disease and then to CMM. • Different combinations of sarcopenia and obesity exhibit distinct risk patterns: individuals with obesity or SO have a higher probability of transitioning to CMM, whereas those with sarcopenia alone face a higher probability of death. • These findings underscore the necessity for differentiated management strategies tailored to specific sarcopenia-obesity phenotypes.