Intrinsic capacity and risk of hip fracture in older adults: evidence from five multinational aging cohorts

BACKGROUND: Hip fracture poses a substantial threat to the quality of life in older adults. Evidence regarding the association between intrinsic capacity (IC) and hip fracture is limited. This study aimed to investigate the relationship between IC and hip fracture risk in older populations. METHODS: This multi-cohort study included five nationally representative aging cohorts: the China Health and Retirement Longitudinal Study (CHARLS), the Health and Retirement Study (HRS), the Mexican Health and Aging Study (MHAS), the Survey of Health, Ageing and Retirement in Europe (SHARE), and the English Longitudinal Study of Ageing (ELSA). Participants aged 60 years and older with baseline IC assessments and at least two follow-ups were included. Individuals with baseline hip fracture, missing hip fracture data, missing covariate data, or lost to follow-up were excluded. IC was comprehensively evaluated across five domains: cognition, locomotion, vitality, sensory function, and psychological function. Hip fractures were identified through self-report or physician diagnosis. Cox proportional hazards regression models were used to estimate the association between IC and hip fracture, and results were pooled across cohorts using a common-effects meta-analysis. RESULTS: A total of 37,267 participants were included, with hip fracture prevalence ranging from 1.40% in SHARE to 4.64% in CHARLS. Higher IC was significantly associated with lower hip fracture risk in all cohorts: CHARLS (HR = 0.75, 95% CI [0.67-0.84]), HRS (HR = 0.65, 95% CI [0.53-0.78]), MHAS (HR = 0.77, 95% CI [0.63-0.95]), SHARE (HR = 0.83, 95% CI [0.72-0.95]), and ELSA (HR = 0.74, 95% CI [0.57-0.98]). The pooled estimate from the common-effects model was HR = 0.76 (95% CI [0.71-0.81], I² = 10.7%). In addition, Sensitivity analyses further supported the robustness of these findings. CONCLUSIONS: Higher IC is associated with a lower risk of hip fracture among older adults. IC may serve as an early predictive indicator of hip fracture, supporting preventive strategies to reduce the economic and societal burden of hip fractures and to preserve quality of life in aging populations.