title: Physical inactivity, excess adiposity and premature mortality.
abstract: The purpose of this report is to review the evidence that physical inactivity and excess adiposity are related to an increased risk of all-cause mortality, and to better identify the independent contributions of each to all-cause mortality rates. A variance-based method of meta-analysis was used to summarize the relationships from available studies. The summary relative risk of all-cause mortality for physical activity from the 55 analyses (31 studies) that included an index of adiposity as a covariate was 0.80 [95% confidence interval (CI) 0.78-0.821, whereas it was 0.82 [95% CI 0.80-0.84] for the 44 analyses (26 studies) that did not include an index of adiposity. Thus, physically active individuals have a lower risk of mortality by comparison to physically inactive peers, independent of level of adiposity. The summary relative risk of all-cause mortality for an elevated body mass index (BMI) from the 25 analyses (13 studies) that included physical activity as a covariate was 1.23 [95% CI 1.18-1.29], and it was 1.24 [95% CI 1.21-1.28] for the 81 analyses (36 studies) that did not include physical activity as a covariate. Studies that used a measure of adiposity other than the BMI show similar relationships with mortality, and stratified analyses indicate that both physical inactivity and adiposity are important determinants of mortality risk.
authors.affiliation: School of Physical and Health Education, Queen's University, Kingston, ON, Canada. katzmarz@post.queensu.ca
authors.forename: P T
authors.initials: PT
authors.lastname: Katzmarzyk
authors.forename: I
authors.initials: I
authors.lastname: Janssen
authors.forename: C I
authors.initials: CI
authors.lastname: Ardern
mesh_terms: D000273:Adipose Tissue / Q000254:growth & development*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition / Q000502:physiology*; D001824:Body Constitution; D002423:Cause of Death; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D015201:Meta-Analysis as Topic; D008875:Middle Aged; D009765:Obesity / Q000401:mortality*; D010809:Physical Fitness / Q000502:physiology; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors