Independent and joint relationships of physical activity and pulmonary function with the risk of all-cause mortality.

Abstract

Background: Physical activity (PA) plays a crucial protective role in the overall health outcomes of individuals with chronic obstructive pulmonary disease. However, accurate recommendations for amount and categories of PA are still unclear for individuals with impaired pulmonary function (PF) in community environments. Thus, this study aims to investigate the independent and joint relationships of PA and PF with mortality.

Methods: In a prospective UK Biobank cohort study, PA was collected by touchscreen questionnaires, and metabolic equivalents of task (MET)-minutes/week of total exercise was calculated by walking plus moderate-intensity PA plus vigorous-intensity PA. According to the standard of the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) 2024, GOLD stage 1, GOLD stage 2 and GOLD stages 3-4 were classified as mild, medium and severe PF impairment, respectively. Cox regression was established to analyse the association between PA, PF and the risk of all-cause mortality.

Results: A total of 354 572 participants were included with mean age of 56.0 years. Compared with lowest quintile of PA, highest quintile of PA was associated with lower risk of mortality in individuals with normal PF (HR=0.828), mild (HR=0.768), medium (HR=0.697) and severe PF impairment (HR=0.588). Generally, PF impairment related to mortality, and this relationship was independent of PA (p<0.05), except for individuals adhering to third quintile (1378-2340 MET-minutes/week) of PA (p>0.05). In joint analysis, more severe PF impairment and lower PA had a dose-response relationship with mortality. Moreover, highest quintile of walking/total exercise was associated with elevated mortality, while adhering to high level of vigorous-intensity PA/total exercise ratio achieved lowest risk of mortality, regardless of individuals with or without PF impairment.

Conclusions: There were significant independent and joint relationships of lower PA and PF impairment with the elevated risk of mortality. However, engaging in appropriate total exercise weekly can mitigate adverse effects associated with mild PF decline.