Non-occupational physical activity and risk of 22 cardiovascular disease, cancer, and mortality outcomes: a dose-response meta-analysis of large prospective studies

Abstract

ABSTRACTObjectiveTo estimate dose-response associations between non-occupational physical activity and multiple chronic disease outcomes in the general adult population.Eligibility criteriaProspective cohort studies with (a) general population samples >10,000 adults, (b) ≥3 exposure categories, and (c) risk measures and confidence intervals for all-cause mortality, total cardiovascular disease, coronary heart disease, stroke, heart failure, total cancer, and site-specific cancers (head and neck, myeloid leukemia, myeloma, gastric cardia, lung, liver, endometrium, colon, breast, bladder, rectum, esophagus, prostate, kidney).Information sourcesPubMed, Scopus, Web of Science, and reference lists of published studies, searched in February 2019.Data extraction and synthesisIndependent extraction and double-checking of study characteristics, exposure, and outcome assessment by two reviewers for each paper. Primary exposure was non-occupational physical activity volume, harmonized to physical activity energy expenditure in marginal MET-hours per week (mMET-h/week). The current minimum recommendations for physical activity (150 min/week of moderate-to-vigorous physical activity) equate to 8.75 mMET-h/week. Outcomes were risks of mortality, cardiovascular diseases, and cancers. We used restricted cubic splines in random-effects meta-analyses. Potential population impact was quantified using impact fractions.Results196 articles were included, covering 94 cohorts. The evidence base was largest for all-cause mortality (50 independent results; 163,415,543 person-years; 811,616 events), and incidence of cardiovascular disease (37 independent results; 28,884,209 person-years; 74,757 events) and cancer (31 independent results; 35,500,867 person-years; 185,870 events). In general, inverse non-linear associations were observed, steeper between 0 and 8.75 mMET-h/week, with smaller marginal reductions in risk above this level to 17.5 mMET-h/week, beyond which additional reductions were small and uncertain. Associations were stronger for all-cause and cardiovascular disease mortality than for cancer mortality. If all insufficiently active individuals had met the recommended physical activity level, 15.7% (95%CI: 13.1 to 18.2%) of all premature deaths would have been averted.ConclusionsInverse non-linear dose-response associations suggest substantial protection against a range of chronic disease outcomes from small increases in non-occupational physical activity in inactive adults.Review registrationPROSPERO CRD42018095481.