Longitudinal association of lung function with frailty among older adults: the English Longitudinal Study of Ageing

Purpose To investigate the effect of baseline lung function on the trajectory of frailty over time. Methods This longitudinal study included 3,658 adults aged 60 and over (average age 70.4 years old and 46.4% males) at baseline from the English Longitudinal Study of Ageing. Lung function indicators included forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1), both measured at baseline examination. Frailty was defined based on Fried's frailty phenotype criteria, the measurement was repeated for four times. Linear mixed-effect regression model was applied to estimate the association of baseline lung function with the trajectory of frailty over time. Results Frailty score increased significantly over time (beta = 0.030, P < 0.001). Linear mixed-effect regression model identified significant interactions between FVC (beta =- 0.018, P < 0.001) or FEV1 (beta =- 0.022, P < 0.001) and time on frailty. Conclusion Poor baseline lung function might accelerate the speed of frailty. Lung function might be an important predictor of the development and progression of frailty among older adults.