Purpose: Increasing obesity prevalence rates in the general population are reflected in patients with type 2 diabetes. Health-related quality of life (HRQoL) is negatively affected in patients who are overweight or have diabetes, but physical activity (PA) is proven to have positive side effects on the perceived quality of life. Little is known about the relationship of PA with obesity, diabetes, and HRQoL. Therefore, the objective of the present study was to examine the relationship between HRQoL and PA in type 2 diabetics in association with the severity of overweight.
Methods: This was a cross-sectional multicenter cohort study involving 370 outpatients with type 2 diabetes. Participants completed the SF-36 Health Survey (SF-36(®)) and the Freiburger Questionnaire for Physical Activity (FFkA). Endurance capacity was tested with a 2 km walking test. t-tests, analysis of variance, Pearson's correlation test, and multiple regression analyses were performed.
Results: HRQoL is negatively affected by body mass index (BMI). The results show that patients with type 2 diabetes and grade II obesity (BMI > 35) have a lower HRQoL than overweight patients (BMI 25-29.99) and patients with grade I obesity (BMI 30-35). HRQoL decreases with decreasing PA in all dimensions of the SF-36. PA remains a significant predictor of physical composite summary (B = 0.09; β = 0.11; P < 0.05), physical function (B = 0.10; β = 0.13; P < 0.01), mental composite summary (B = 0.13; β = 0.20; P < 0.001), vitality (B = 0.15; β = 0.24; P < 0.001), and psychological well-being (B = 0.11; β = 0.18; P < 0.01) when controlling for age, sex, and BMI.
Conclusion: Because of the strong association between being overweight/obese and several risk factors for morbidity and mortality, reversing the obesity epidemic is an urgent priority. Based upon the results of this study and the available evidence of the efficacy of PA for preventing and treating those who are overweight or obese, health care professionals should continue to stress the importance of PA as a treatment option.
Keywords: diabetes mellitus type 2; health-related quality of life; obesity; physical activity.