Abstract Body: Background
Intrinsic capacity (IC), proposed by the World Health Organization, is a core indicator for assessing the physical and mental health of older adults. Past studies have revealed the strong predictive power of IC for adverse outcomes, including mortality and disability. However, its longitudinal association with the risk of cardiovascular diseases (CVD) remains poorly understood. This study aims to explore the association between changes in IC and the risk of CVD in 19 countries across Europe, Asia, and the Americas.
Method
This longitudinal multi-region study applied individual-level data from five studies on ageing between 2001 and 2022 in the Program on Global Aging, Health, and Policy: the US Health and Retirement Study (HRS); the English Longitudinal Study on Ageing (ELSA); the Survey of Health, Ageing and Retirement in Europe (SHARE); the China Health and Retirement Longitudinal Study (CHARLS); and the Mexican Health and Aging Study (MHAS). Adults aged 50 or older and free of CVD (including stroke and heart disease) at baseline were included. IC was measured across five domains: cognition, locomotion, psychology, vitality, and sensory. Each domain was scored 0–2, and IC score ranged from 0-10. We categorized IC score into 3 levels (low: 0–4.5, medium: 5–8, high: 8.5–10). IC changes across two waves were classified as “high stable”, “moderate stable”, “low stable”, “improved”, and “decreased”. The main outcome was the occurrence of CVD during the follow-up period. We used cause-specific Cox proportional hazards models to examine the effects of IC change on CVD risk. Models were adjusted for demographics and lifestyles.
Result
Among 35660 individuals (46%-62% male), we found a decline in IC was associated with an increased risk of CVD in HRS ( Hazard Ratio (HR) = 1.24, 95% CI: 1.06–1.45), SHARE (HR = 1.28, 95% CI: 1.12–1.46), and ELSA (HR = 2.38, 95% CI: 1.50–3.76) cohorts. In the CHARLS cohort, a non-significant trend toward higher CVD risk was observed. In the MHAS cohort, an improvement in IC was associated with a reduced risk (HR = 0.61, 95% CI: 0.46–0.82).
Conclusion
In older adult populations of multiple countries, the decline in IC is related to an increased risk of future CVD, while improving IC from a low level is associated with a reduction in the CVD risk. These findings underscore the prognostic value of IC in predicting CVD and highlight the importance of maintaining functional reserves during aging.