Association between physical activity and cardiovascular-kidney-metabolic syndrome in older Chinese adults: a nationwide, cross-sectional study

Background: Cardiovascular-kidney-metabolic (CKM) syndrome represents a new framework to address the non-communicable disease burden in ageing populations. However, evidence on the association between physical activity and the integrated CKM syndrome is scarce, particularly among older Asian adults. We aimed to investigate this association in a large sample of older Chinese adults. Methods: This cross-sectional study utilised data from the China Ageing and Health Survey, including 41 829 community-dwelling adults aged ≥65 years. Physical activity was assessed using the validated Physical Activity Scale for the Elderly (PASE). Cardiovascular-kidney-metabolic syndrome was defined based on the 2023 American Heart Association criteria (Stages 1-4 vs. Stage 0). Multivariable logistic regression models were used to examine the association between PASE quartiles and CKM syndrome prevalence. Results: The prevalence of CKM syndrome was 80.3%. After full adjustment, a significant inverse dose-response relationship was observed between physical activity and CKM syndrome (P for trend <0.001). Participants in the highest physical activity quartile had 21% lower odds of CKM syndrome compared to the lowest quartile (adjusted odds ratio (aOR) = 0.79; 95% CI = 0.74-0.85). This inverse association was consistent across sexes but was strongly age-dependent: it was most pronounced among individuals aged ≥80 years (P for trend <0.001) and non-significant in the 65-69 age group (P for trend >0.05). Conclusions: Higher physical activity is independently associated with a lower prevalence of CKM syndrome in older Chinese adults. This inverse association was strikingly age-dependent and most pronounced in the oldest-old (aged ≥80 years). For aging populations globally, promoting accessible, age-appropriate physical activity may represent a high-priority, low-cost public health strategy to reduce CKM burden, particularly in this most vulnerable demographic.