비만인에서 베타3-아드레날린성 수용체 유전자변이에 따른 체지방 분포양상과 체중감량의 효과

Abstract

Background: Recently, missense mutation of the β₃-adrenergic receptor gene has been shown to be associated with early onset of type 2 diabetes, abdominal obesity and an increased capacity to gain weight. This study was performed to investigate the effects of Trp64Arg mutation in the β3-adrenergic receptor gene on body fat distribution and weight loss in obese subjects. Methods: Determination of the β₃-adrenergic receptor gene mutation with restriction enzyme digestion method, anthropometry, various biochemical studies, including oral glucose tolerance test were performed in 99 obese and 35 control subjects. Body fat distributions were also evaluated by computerized tomography before and after weight-reduction program. Results: 1) There were no differences in the frequencies of Trp64Arg mutation in the β₃-adrenergic receptor gene between obese and control subjects (15.2 vs 12.9 %). 2) The obese subjects with Trp64Arg mutation had higher waist to hip circumference ratio(WHR) (0.93±0.05 vs 0.87±0.04, p<0.001), visceral fat area (115.0±25.9 vs 86.4±41.4 ㎠, p=0.01), but decreased plasma free fatty acid (618.0±163.1 vs 817.5±248.2 μEq/L, p=0.001), and triglyceride level (118.7±36.2 vs 158.4 ± 105.8 mg/dL, p=0.015) than those without mutation. 3) The obese subjects with Trp64Arg mutation had smaller decreases in weight (- 3.4 vs -5.1 kg, p<0.001), body fat content (-2.1 vs -3.8 %, p<0001), WHR (-0.01 vs -0.03, p=0.025), and abdominal fat masses (total, subcutaneous, and visceral fat) after weight-reduction program than those without mutation. Conclusion: Trp64Arg mutation in the β₃-adrenergic receptor gene might be one of genetic loci contributing to central obesity and a predictor of difficulty in losing weight in obese subjects.