Estimation of the relationship between body mass index and EQ-5D health utilities in individuals with type 2 diabetes: evidence from the population-based KORA studies.
OBJECTIVE
Obesity is known to be an important risk factor for type 2 diabetes and its related comorbid conditions; however, its specific impact on generic health-related quality of life (HRQL) is less clear. The objective of this study was to estimate the association between body mass index (BMI) and HRQL in individuals with type 2 diabetes.


METHODS
The EQ-5D quality of life questionnaire was administered in a follow-up of 10,385 participants aged 33-94 of the population-based German MONICA/KORA surveys. 1033 participants with type 2 diabetes were identified by self-report combined with validated physician diagnoses. Semiparametric additive regression models were used to estimate the effect of BMI on EQ-5D health utilities adjusted for age, sex, education and comorbidities.


RESULTS
BMI was significantly associated with EQ-5D health utilities even after adjustment for macro- and microvascular complications. The functional relationship between BMI and utilities was nonlinear, reflecting optimal health around 26 kg/m² and significantly decreasing health utilities with increasing levels of overweight and obesity (-0.09 points between BMI values 26 and 40). Among the diabetic complications, the history of a stroke (-0.13) and neuropathy (-0.10) were the strongest predictors of reduced health utility scores.


CONCLUSIONS
BMI is strongly associated with health utilities in persons with type 2 diabetes. This suggests that lifestyle measures to reduce obesity can markedly improve patients' health-related quality of life and that the negative effect of potential weight gain should be taken into account when determining patient preferences for different type 2 diabetes treatment options.
Helmholtz Zentrum München - German Research Center for Environmental Health, Institute of Health Economics and Health Care Management, 85764 Neuherberg, Germany. matthias.hunger@helmholtz-muenchen.de
Matthias
M
Hunger
Michaela
M
Schunk
Christa
C
Meisinger
Annette
A
Peters
Rolf
R
Holle
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015897:Comorbidity; D017281:Cost of Illness; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D003929:Diabetic Neuropathies / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005858:Germany / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D050177:Overweight / Q000453:epidemiology*; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D020521:Stroke / Q000453:epidemiology