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 P = 0.003). There were no significant differences between participants with and without diabetes in the mental component score. Conclusion 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. Trial registration NCT00212303