title: Increases in physical activity may affect quality of life differently in men and women: the PACE project.
abstract: OBJECTIVE
  Obesity is associated with impaired quality of life (QoL), but less is known about physical activity. We investigated how decreases in body mass index (BMI) and increases in activity affect obesity-specific QoL and potential gender differences in associations.
  
  
  METHODS
  In a large worksite randomized trial of a multilevel intervention on diet and physical activity behaviors, we conducted a cohort analysis at two years of follow-up. Self-reported activity and Obesity and Weight Loss Quality of Life (OWLQOL) were analyzed for individual-level associations using linear mixed models accounting for random worksite effects.
  
  
  RESULTS
  Gender modified the BMI-OWLQOL relationship, so analyses were conducted for males and females separately. Adjusting for demographic confounders, baseline OWLQOL, and several worksite-level variables including intervention arm, a 1.9 unit decrease in BMI (the interquartile range) was associated with an OWLQOL increase of 1.7 (95 % CI: 1.2, 2.2) in males and 3.6 (95 % CI: 3.2, 4.0) in females. Similarly, a 23 unit increase in physical activity score was associated with an OWLQOL increase of 0.9 (95 % CI: 0.5, 1.4) in males and 1.6 (95 % CI: 1.0, 2.3) in females. Physical activity associations were attenuated when adjusting for change in BMI, but remained significant for women (mean BMI 27.8 kg/m(2)).
  
  
  CONCLUSIONS
  This is the first study to demonstrate that increasing physical activity may improve obesity-specific QoL to a greater extent in women, particularly among overweight women, independent of BMI. Results may inform the design of interventions tailored to women targeting well-being through messages of increasing physical activity.
authors.affiliation: The Parkinson's Institute and Clinical Center, 675 Almanor Ave, Sunnyvale, CA, 94085, USA.
authors.forename: Stephanie Whisnant
authors.initials: SW
authors.lastname: Cash
authors.forename: Glen E
authors.initials: GE
authors.lastname: Duncan
authors.forename: Shirley A A
authors.initials: SA
authors.lastname: Beresford
authors.forename: Anne
authors.initials: A
authors.lastname: McTiernan
authors.forename: Donald L
authors.initials: DL
authors.lastname: Patrick
mesh_terms: D000328:Adult; D015992:Body Mass Index; D004032:Diet; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009765:Obesity / Q000503:physiopathology* / Q000523:psychology / Q000628:therapy; D050177:Overweight; D011788:Quality of Life; D057566:Self Report; D012737:Sex Factors; D015431:Weight Loss; D017132:Workplace