Intrinsic capacity trajectories and cardiovascular disease incidence among Chinese older adults: a population-based prospective cohort study.

backgroundIntrinsic capacity (IC), a composite of physical and mental capacities, is a marker of healthy aging. However, the association between changes in IC and trajectories in older adults and the onset of cardiovascular diseases (CVD) remains unclear.

objectiveTo identify IC trajectories over time and assess the associations between IC trajectories and the incidence of CVD among older adults.

methodsThe prospective cohort study used data from the China Health and Retirement Longitudinal Study (CHARLS) between 2011 and 2020. To determine IC trajectory during 2011-2015, we included adults aged 60 years or older without CVD at baseline, who completed the follow-up visits in 2013 and 2015. We assessed IC through five domains (locomotion, sensory, vitality, cognition, and psychology) using the WHO framework. We determined the onset of CVD by self-reported diagnoses of heart disease or stroke. We performed a group-based trajectory model to identify IC trajectory, and cox proportional hazard models to estimate the adjusted hazard ratio (HR) for CVD incident across different IC trajectory groups, adjusting for sociodemographic factors, lifestyle health behaviors, and cardiovascular metabolic factors.

resultsThe study included 3 336 adults without CVD at baseline, with the mean age of 66.64 (SD:5.53) years, and 49.4% were male. The baseline mean IC score was 5.40 (SD:1.70). We identified three IC trajectory: (1) moderate IC with subsequent increase (61.3%), (2) low IC with slow decline (27.61%), and (3) high IC with subsequent decline (11.09%). During the average follow-up of 6.78 years, we identified 1,351 cases of incident CVD. After adjusting for covariates, adults who in the low IC with slow decline group were 1.68 (95% CI: 1.38-2.04) times more likely to develop CVD, compared to adults in the high IC with subsequent decline group.

conclusionIC trajectory among Chinese older adults is heterogeneous. Low IC with slow declining is associated with an increased risk of CVD incidence.