Association of Peak Expiratory Flow with Cognitive Function in the Chinese Middle-Aged and Elderly Population: A 7-Year Longitudinal Study.

Abstract

Previous studies have shown that impaired pulmonary function may be associated with cognitive decline, posing the question of whether peak expiratory flow (PEF) % pred could present a modifiable risk factor. To assess the association between PEF% pred and future cognitive function among Chinese participants aged 45 years and above. Data came from four waves fielded by the China Health and Retirement Longitudinal Study. Cognitive function was assessed by a global cognition score. Multivariate linear regression models and generalized estimating equation (GEE) were used to investigate associations between PEF% pred and later cognitive function. A total of 2,950 participants were eligible for the final data analysis. After adjustment for baseline cognition and potential confounders, the association remained statistically significant (β = 0.0057, p = 0.027). Domains with increases were focused on episodic memory (β= 0.0028, p = 0.048) and figure drawing (β= 0.0040, p = 0.028). But these associations were not found in women (β= 0.0027, p = 0.379). However, GEE suggested that the rates of decline in global cognition decreased by 0.0096 (p < 0.001) units per year as baseline PEF% pred increased by 1% in middle-aged and elderly individuals, regardless of sex. And higher baseline PEF% pred correlated with declined rates of decrease of in episodic memory, figure drawing, and Telephone Interview of Cognitive Status (TICS). Higher baseline PEF% pred was significantly associated with slower cognitive decline in global cognition, episodic memory, figure drawing, and TICS in middle aged and elderly Chinese adults.