OBJECTIVE -The aim of this study was to determine whether overweight and obese individuals with type 2 diabetes have higher basal and 24-h energy expenditure compared with healthy control subjects before and after adjustment for body composition, spontaneous physical activity (SPA), sex, and age.RESEARCH DESIGN AND METHODS -Data from 31 subjects with type 2 diabetes and 61 nondiabetic control subjects were analyzed. The 24-h energy expenditure, basal metabolic rate (BMR), and sleeping energy expenditure (EE sleep ) between 1:00 A.M. and 6:00 A.M. were measured in whole-body respiratory chambers. Body composition was assessed by dual-energy X-ray absorptiometry (DXA).RESULTS -No significant differences in unadjusted EE sleep , BMR, and 24-h energy expenditure were observed between the type 2 diabetic group and the control group. After adjustment for fat-free mass (FFM), fat mass, SPA, sex, and age, EE sleep and BMR were, respectively, 7.7 and 6.9% higher in the type 2 diabetic group compared with the control group. This was equivalent to 144 Ϯ 40 kcal/day (P ϭ 0.001) and 139 Ϯ 61 kcal/day (P ϭ 0.026), respectively. Adjusted 24-h energy expenditure was 6.5% higher in the type 2 diabetic group compared with the nondiabetic control subjects (2,679 Ϯ 37 vs. 2,515 Ϯ 23 kcal/day, P ϭ 0.002). In multiple regression analyses, FFM, fat mass, SPA, and diabetes status were all significant determinants of EE sleep and 24-h energy expenditure, explaining 83 and 81% of the variation, respectively.CONCLUSIONS -This study confirms reports in Pima Indians that basal and 24-h energy expenditure adjusted for body composition, SPA, sex, and age are higher in individuals with type 2 diabetes compared with nondiabetic control subjects and may be even more pronounced in Caucasians.
Diabetes Care 27:2416 -2421, 2004T he development of type 2 diabetes depends on both genetic susceptibility and environmental factors (1). An inappropriately high-energy intake and a sedentary lifestyle are wellknown risk factors for obesity, and there is solid evidence that excessive fat mass is the major cause of type 2 diabetes (2,3). Furthermore, large intervention trials have demonstrated that even a moderate, sustained weight loss in high-risk individuals can reduce the incidence of type 2 diabetes (4,5). However, genetic and disease-related differences in energy expenditure may also be important etiological determinants.A low resting energy expenditure (EE rest ) is a risk factor for weight gain (6). Paradoxically, cross-sectional studies have indicated an ϳ5% increased EE rest in Pima Indians with type 2 diabetes compared with nondiabetic individuals after adjustment for age and body composition (7-9). Other studies found a decreased thermogenic response to meals (10) and insulin/glucose clamp infusions among type 2 diabetic subjects compared with nondiabetic individuals (11). Thus, the integrated effect on total 24-h energy expenditure has been reported to be similar or only slightly elevated in Pima Indians with type 2 diabetes compared with nondia...