Association of pulmonary function with mild cognitive impairment and brain pathologies: a community‐based cohort study

Abstract

AbstractBackgroundThe association of pulmonary function (PF) with mild cognitive impairment (MCI) and its underlying mechanisms remain unclear. We examined the association of PF with MCI and brain pathologies.MethodWithin the Rush Memory and Aging Project, the 1025 no cognitive impairment (NCI) participants (mean age: 79.41±7.77 years) were followed for up to 21 years to detect incident MCI. PF was assessed with a composite score based on forced vital capacity, forced expiratory volume in 1s, and peak expiratory flow measured at baseline, and further divided into tertiles (i.e., lowest, middle, and highest). MCI was diagnosed following standard criteria. During the follow‐up, 396 participants died and underwent autopsies for neuropathological assessment (including Alzheimer’s disease [AD], and vascular brain pathologies). Data were analyzed using Cox regression, Laplace regression, and Logistic regression.ResultDuring the follow‐up (median 7 years, interquartile range 4‐10 years), 461 participants developed MCI. Compared to the highest PF, the multi‐adjusted HR (95% CI) was 2.07 (1.55‐2.78) for MCI. The median time from NCI to MCI development was 4.05 (95% CI: 2.78‐5.31) years shorter in people with the lowest PF than those with the highest PF. In the pathological data analysis, the lowest PF was significantly related to higher AD pathology (odds ratio [OR]: 1.45, 95% CI: 1.29‐1.62) and vascular brain pathologies (OR: 3.47, 95% CI: 1.50‐8.03) compared to the highest PF.ConclusionThe lowest PF is associated with a 2‐fold risk of MCI and accelerates progression from NCI to MCI by more than 4 years. Both neurodegenerative and vascular mechanisms may underlie this association.