title: Fatness and fitness: how do they influence health-related quality of life in type 2 diabetes mellitus?
abstract: OBJECTIVE
  We examined whether adiposity and fitness explain the decrease in health-related quality of life (HRQOL) associated with type 2 diabetes mellitus.
  
  
  METHODS
  This was a cross-sectional study using baseline data from two exercise training interventions. One study enrolled people with and the other without type 2 diabetes. We assessed aerobic fitness ("fitness") as peak oxygen uptake during treadmill testing, adiposity ("fatness") as percentage of total body fat by dual-energy x-ray absorptiometry, and HRQOL by the Medical Outcomes Study SF-36. Bivariate and multivariate linear regression analyses were used examine determinants of HRQOL were used to examine determinants of HRQOL.
  
  
  RESULTS
  There were 98 participants with and 119 participants without type 2 diabetes. Participants with type 2 diabetes had a mean hemoglobin A1c of 6.6% and, compared with participants without diabetes had lower HRQOL on the physical component summary score (P = 0.004), role-physical (P = 0.035), vitality (P = 0.062) and general health (P < 0.001) scales after adjusting for age, sex and race. These associations of HRQOL with type 2 diabetes were attenuated by higher fitness, even more than reduced fatness. Only general health remained positively associated with type 2 diabetes after accounting for fatness or fitness (P = 0.003). There were no significant differences between participants with and without diabetes in the mental component score.
  
  
  CONCLUSIONS
  Improved fitness, even more than reduced fatness, attenuated the association of type 2 diabetes with HRQOL. The potential to improve HRQOL may motivate patients with type 2 diabetes to engage in physical activity aimed at increasing fitness. Findings from this cross-sectional analysis will be addressed in the ongoing trial of exercise training in this cohort of participants with type 2 diabetes.
  
  
  BACKGROUND
  NCT00212303.
authors.affiliation: Department of Medicine, Division of General Internal Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA. wbennet5@jhmi.edu
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Bennett
authors.forename: Pamela
authors.initials: P
authors.lastname: Ouyang
authors.forename: Albert W
authors.initials: AW
authors.lastname: Wu
authors.forename: Bethany B
authors.initials: BB
authors.lastname: Barone
authors.forename: Kerry J
authors.initials: KJ
authors.lastname: Stewart
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D048909:Diabetes Complications / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness / Q000502:physiology*; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014481:United States