Adverse health effects of declined intrinsic capacity in middle-aged and older adults: a systematic review and meta-analysis

Background Intrinsic capacity refers to a broad range of health traits, including the physiological and psychological changes brought on by aging. Previous research has shown that intrinsic capacity, as an independent emerging construct, is a highly effective predictor of several health outcomes.Objective We aimed to summarise the predictive effect of intrinsic capacity at baseline on health outcomes among middle-aged and older adults.Design A systematic review and meta-analysis.Participants Middle-aged and older adults.Methods We systematically searched up to 3 April 2024 in 10 electronic databases. Studies investigating the predictive effect of baseline composite intrinsic capacity and health outcomes were included. Publications that had reported hazard ratios (HRs) or odd ratios (ORs) and 95% confidence intervals (CIs) as effect size were considered.Results A total of 23 publications were included. The sample size ranged from 100 to 17 031. The results of the meta-analysis showed statistically significant prediction of adverse health outcomes such as disability (OR = 1.84, 95% CI: 1.68-2.03, I2 = 41%, Pheterogeneity=.10), falls (OR = 1.38, 95% CI: 1.19-1.60, I2 = 45%, Pheterogeneity=.11), hospitalisation (OR = 2.25, 95% CI: 1.17-4.3, I2 = 68%, Pheterogeneity=.08), mortality (OR = 1.72, 95% CI: 1.54-1.91, I2 = 32%, Pheterogeneity=.12) and frailty (OR = 1.57, 95% CI: 1.45-1.70, I2 = 2%, Pheterogeneity=.31) by the baseline composite intrinsic capacity.Conclusions Declined intrinsic capacity has potential predictive value for adverse health outcomes, further high-quality study is needed to validate these findings and strengthen their cumulative impact. Attention to health outcomes should also focus on both breadth and category precision.