Cross-national evidence on frailty-depression multi-trajectories and osteoporosis risk: Findings from the ELSA and HRS cohorts.

BACKGROUND: Frailty and depression commonly co-occur in older adults and may jointly elevate the risk of osteoporosis. However, evidence on their long-term multi-trajectories and impact on osteoporosis is limited, particularly across different populations.

METHODS: We analyzed data from 2971 participants aged ≥50 years without osteoporosis at baseline in the English Longitudinal Study of Ageing (ELSA) and 5199 participants from the U.S. Health and Retirement Study (HRS). Group-based multi-trajectories modeling identified frailty-depression trajectories, and incident osteoporosis was ascertained through self-reported physician diagnosis during follow-up. Cox proportional hazards models estimated associations of trajectory groups with osteoporosis risk, adjusting for demographics and lifestyle factors.

RESULTS: Over a median follow-up of 10 years in ELSA and 7.9 years in HRS, three consistent frailty-depression trajectories were identified in both cohorts-stable low, increasing moderate, and persistent high-accompanied by 220 (7.4 %) and 867 (16.7 %) incident osteoporosis cases, respectively. Compared with the stable low frailty-low depression group, the risk of osteoporosis was significantly higher for the persistent high frailty-high depression group (ELSA: HR = 2.52, 95 % CI 1.50-4.24; HRS: HR = 2.66, 95 % CI 2.12-3.35) and for the increasing moderate frailty-moderate depression group (ELSA: HR = 1.47, 95 % CI 1.03-2.09; HRS: HR = 1.45, 95 % CI 1.24-1.70).

CONCLUSION: Across both the UK and US cohorts, long-term multi-trajectories of frailty and depression were strongly associated with the incidence of osteoporosis. Individuals with persistent high frailty-high depression had the greatest risk, whereas those with increasing moderate frailty-moderate depression also experienced cumulative risk. Prevention should extend beyond skeletal targets to include early, integrated strategies addressing functional decline and mental health in older adults.