Higher estimated cardiorespiratory fitness levels were associated with lower risk of cardiometabolic multimorbidity: a retrospective cohort study from CHARLS.

BACKGROUND AND AIMS: Cardiometabolic multimorbidity (CMM) is significantly associated with an increased risk of all-cause mortality. However, evidence on the relationship between cardiorespiratory fitness (CRF) and CMM remains limited, particularly in Chinese populations.

METHODS AND

RESULTS

Data were derived from the China Health and Retirement Longitudinal Study. A total of 5,255 participants aged ≥45 years with up to 9 years of follow-up were included. Sex-specific body mass index (BMI)-based models were used to evaluate estimated CRF (eCRF). Skeletal muscle mass was assessed using appendicular skeletal muscle mass (ASM) and appendicular skeletal muscle mass index (ASMI). During the 9-year follow-up, 441 (8.4%) participants developed CMM. Kaplan-Meier survival analysis demonstrated that higher eCRF levels were associated with a lower cumulative risk of CMM. Multivariable Cox proportional hazards regression analysis revealed that after full adjustment for confounders, each 1-MET (1 mL kg-1·min-1) increase in eCRF was associated with an 18.9% (5.8%) reduction in the risk of CMM. In quartile analysis of eCRF, compared with the lowest quartile (Q1), the risk of CMM was 25.5% lower in Q2, 46.5% lower in Q3, and 61.0% lower in Q4. The fully adjusted RCS analysis indicated a linear relationship between eCRF and CMM risk. Mediation analysis suggested that skeletal muscle mass statistically mediated the association between eCRF and CMM, with mediated proportions of 22.69% for ASM and 40.54% for ASMI.

CONCLUSION

Higher eCRF was associated with a reduced risk of CMM, and this association may be partially mediated by skeletal muscle mass.