Association between frailty and chronic lung diseases in middle aged and older population

Previous studies have linked frailty in older adults to poor health outcomes, particularly chronic lung disease (CLD). However, this study innovatively concentrated on changes over time rather than solely on the initial frailty status, aiming to investigate the relationship between initial frailty status, its progression, and the incidence of CLD. Using data from the China Health and Retirement Longitudinal Study (CHARLS), frailty was assessed with the Rockwood frailty index. Among 6,943 participants, 4,624 (66.6%) were robust, 2,140 (30.8%) prefrail, and 179 (2.6%) frail. Changes in frailty status were evaluated over a two-year follow-up, with CLD identified through self-reported physician diagnoses. Cox proportional hazards models calculated hazard ratios (HR) and 95% confidence intervals (CI), adjusting for confounders. Robust individuals who progressed to pre-frail or frail status had a higher risk of CLD (HR = 1.57, 95% CI: 1.27–1.93). Conversely, frail participants who improved to robust or pre-frail status showed a lower risk (HR = 0.78, 95% CI: 0.37–1.61). Additionally, pre-frail participants who regained robust status had reduced CLD risk (HR = 0.59, 95% CI: 0.44–0.80). Frailty progression increases CLD risk, while recovery decreases it, underscoring the importance of frailty screening in clinical practice for preventing and managing CLD in the ageing population.