title: Quantifying the Association Between Physical Activity and Cardiovascular Disease and Diabetes: A Systematic Review and Meta-Analysis.
abstract: The relationships between physical activity (PA) and both cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM) have predominantly been estimated using categorical measures of PA, masking the shape of the dose-response relationship. In this systematic review and meta-analysis, for the very first time we are able to derive a single continuous PA metric to compare the association between PA and CVD/T2DM, both before and after adjustment for a measure of body weight.
  
  
  
  The search was applied to MEDLINE and EMBASE electronic databases for all studies published from January 1981 to March 2014. A total of 36 studies (3 439 874 participants and 179 393 events, during an average follow-up period of 12.3 years) were included in the analysis (33 pertaining to CVD and 3 to T2DM). An increase from being inactive to achieving recommended PA levels (150 minutes of moderate-intensity aerobic activity per week) was associated with lower risk of CVD mortality by 23%, CVD incidence by 17%, and T2DM incidence by 26% (relative risk [RR], 0.77 [0.71-0.84]), (RR, 0.83 [0.77-0.89]), and (RR, 0.74 [0.72-0.77]), respectively, after adjustment for body weight.
  
  
  
  By using a single continuous metric for PA levels, we were able to make a comparison of the effect of PA on CVD incidence and mortality including myocardial infarct (MI), stroke, and heart failure, as well as T2DM. Effect sizes were generally similar for CVD and T2DM, and suggested that the greatest gain in health is associated with moving from inactivity to small amounts of PA.
authors.affiliation: John Radcliffe Hospital, Oxford & University of Oxford Clinical Academic Graduate School (OUCAGS), Oxford, United Kingdom.
authors.forename: Ahad
authors.initials: A
authors.lastname: Wahid
authors.affiliation: Watford General Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.
authors.forename: Nishma
authors.initials: N
authors.lastname: Manek
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom WHO Collaborating Center for Obesity Prevention, Deakin University, Geelong, Australia.
authors.forename: Melanie
authors.initials: M
authors.lastname: Nichols
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom Sport, Physical Education and Health Sciences Department (SPEHS), University of Edinburgh, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Kelly
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom.
authors.forename: Charlie
authors.initials: C
authors.lastname: Foster
authors.affiliation: Nuffield Department of Population Health, University of Oxford, United Kingdom.
authors.forename: Premila
authors.initials: P
authors.lastname: Webster
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom.
authors.forename: Asha
authors.initials: A
authors.lastname: Kaur
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom Department of Epidemiology and Public Health, Health Behaviour Research Centre, University College London, London, United Kingdom.
authors.forename: Claire
authors.initials: C
authors.lastname: Friedemann Smith
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Wilkins
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom.
authors.forename: Mike
authors.initials: M
authors.lastname: Rayner
authors.affiliation: Bodleian Health Care Libraries, Knowledge Center, University of Oxford, United Kingdom.
authors.forename: Nia
authors.initials: N
authors.lastname: Roberts
authors.affiliation: The British Heart Foundation Center on Population Approaches for Non-Communicable Disease Prevention, Nuffield Department of Population Health, University of Oxford, United Kingdom peter.scarborough@dph.ox.ac.uk.
authors.forename: Peter
authors.initials: P
authors.lastname: Scarborough
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000401:mortality / Q000517:prevention & control*; D003925:Diabetic Angiopathies / Q000401:mortality / Q000517:prevention & control*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D012307:Risk Factors
keywords: cardiovascular diseases; meta‐analysis; physical activity; systematic review