Energy Expenditure and Body Composition of Type 2 Diabetics Participating in a Clinical Trial of Pharmacologic Induction of Weight Loss

Abstract

Forty-four overweight subjects with type 2 diabetes mellitus were enrolled in a randomized, placebo-controlled, double blind trial of pharmacologic induction of weight loss. All subjects received intensive nutrition counseling, an exercise prescription, instruction on behavioral management, and were randomly assigned to fenfluramine 20 mg three times daily and phentermine 37.5 mg daily (n=23) or dual placebos (n=21). Drug therapy continued until September 1997 when fenfluramine was withdrawn from the US market. Body fat composition was assessed by skinfold measurement. Resting energy expenditure was measured with a DeltaTrac metabolic monitor. Physical activity was assessed by questionnaire. Mean ± SEM baseline data for the placebo group and the active drug group, respectively, were: Weight (kg) 106 ± 4, 108 ± 4; BMI (kg/m 2) 37.7 ± 1.4, 38.5 ± 2.4; Body Fat (%) 39.1 ± 1.7,40.0 ± 2.3; REE (kcal) 2180 ± 73, 2087 ± 173; and weekly energy expenditure in physical activity (PA, kcal) 1410 ± 613, 1267 ± 367. The changes from baseline were as follows (placebo vs. active, **p< .05, *p=.05–1.0): Weight BMI Body Fat REE PA 2 Months (kg) (kg/m 2) (%) (kcal) (kcal) Placebo (n=18) −1.6±0.5 −0.5±0.2 −0.5±0.5 −13±43 344±274 Active (n=21) −7.9±1.2** −2.5±0.4** −3.0±0.7** −265±41** 938±289 6 Months Placebo (n=13) −2.7±1.4 −0.8±0.5 −0.7±0.7 −130±52 1349±503 Active (n=13) −9.6±1.5** −3.2±0.5** −2.5±1.0 −262±62 60±466* 12 Months Placebo (n=8) −2.5±2.5 −0.6±0.8 1.5±1.4 −51±49 1408±546 Active (n=8) −8.1±1.6* −2.6±0.7* −1.8±0.9* −139±27 650±319 The observed reduction in both body weight and BMI were both statistically significant at 2 and 6 months and approaching significance at 12 months in the active group. As expected, the reduction in body weight was accompanied by a reduction in REE and in percentage of body fat.