Association between cardiometabolic index and biological ageing among adults: a population-based study.

Background: Cardiovascular health (CVH) is closely associated with ageing. This study aimed to investigate the association between cardiometabolic index (CMI), a novel indicator of cardiometabolic status, and biological ageing.

Methods: Cross-sectional data were obtained from participants with comprehensive CMI and biological age data in the National Health and Nutrition Examination Survey from 2011 to 2018. Biological age acceleration (BioAgeAccel) is calculated as the differences between biological age and chronological age, and that biological age is derived from a model incorporating eight biomarkers. Weighted multivariable regression, sensitivity analysis, and smoothing curve fitting were performed to explore the independent association between CMI and the acceleration of biological age. Subgroup and interaction analyses were performed to investigate whether this association was consistent across populations.

Results: In 4282 subjects ≥ 20 years of age, there was a positive relationship between CMI and biological age. The BioAgeAccel increased 1.16 years for each unit CMI increase [1.16 (1.02, 1.31)], and increased 0.99 years for per SD increase in CMI [0.99 (0.87, 1.11)]. Participants in the highest CMI quartile had a BioAgeAccel that was 2.49 years higher than participants in the lowest CMI quartile [2.49 (2.15, 2.83)]. In stratified studies, the positive correlation between CMI and biological age acceleration was not consistent across strata. This positive correlation was stronger in female, diabetes, and non-hypertension populations.

Conclusions: CMI is positively correlated with biological ageing in adults in the United States. Prospective studies with larger sample sizes are required to validate our findings.