Dose–response relationship between physical activity and mortality in adults with noncommunicable diseases: A systematic review and meta-analysis of cohort studies

Abstract

ABSTRACTObjectiveTo investigate the relationship between post-diagnosis physical activity and mortality in patients with selected noncommunicable diseases, including breast cancer, lung cancer, type 2 diabetes (T2D), ischemic heart disease (IHD), chronic obstructive pulmonary disease (COPD), stroke, osteoarthritis, low back pain and major depressive disorders.DesignSystematic review and dose–response meta-analysis.Data sourcesPubMed, Scopus and the Web of Science were searched systematically for English publications from the inception of the platforms until August 2018. Additionally, the search was updated in August 2019.Eligibility criteriaProspective observational studies examining the relationship between at least three physical activity categories and all-cause mortality or disease-specific mortality as the primary outcome.ResultsIn total, 28 studies were included: 12 for breast cancer, 6 for T2D, 8 for IHD and 2 for COPD. The linear meta-analysis revealed that each 10 metabolic equivalent tasks (MET) h increase of physical activity per week was associated with a 22% lower mortality rate in breast cancer patients (Hazard Ratio [HR], 0.78; 95% CI: 0.71, 0.86), 12% in IHD patients (HR, 0.88; 95% CI: 0.83, 0.93), 30% in COPD patients (HR, 0.70; 95% CI: 0.45, 1.09) and 4% in T2D patients (HR, 0.96; 95% CI: 0.93, 0.99). The non-linear meta-analysis showed a regressive association with no threshold for the beneficial effect of physical activity on mortality.ConclusionHigher levels of post-diagnosis physical activity are associated with lower mortality rates in breast cancer, T2D, IHD and COPD patients, with evidence of a no-threshold and non-linear dose–response pattern.SUMMARY BOXExisting findings- Higher levels of physical activity are associated with a clear reduction in all-cause mortality in the general population.- In the general population, the shape of the dose–response curve between levels of physical activity and reduced mortality rates is characterized by a regressive, non-linear effect.New findings- Higher levels of post-diagnosis physical activity are associated with a clear reduction in all-cause mortality in adults with breast cancer, T2D, IHD and COPD.- The shape of the indication-specific dose–response curves between post-diagnosis physical activity and mortality are characterized by a regressive, non-linear association with (1) no threshold for the beneficial effect, (2) pronounced reductions of mortality for lower levels of physical activity compared to those who are physically inactive and (3) no harmful effects at higher levels of physical activity.