WEIGHT LOSS--BONE & SKELETAL MUSCLE HOMEOSTASIS IN NIDDM

患有2型糖尿病的严重肥胖女性(BMI在35到40之间)骨量增加。它们的脱脂质量也增加了，可能包括增加的骨骼肌。这些女性不断地试图减肥，以改善她们对糖尿病的控制。过去，减肥的尝试通常是通过医学手段进行的，但严重肥胖的女性正在越来越频繁地接受减肥手术。通过减肥，无论是通过内科还是外科手术，脂肪量都会减少。此外，有一些证据表明，骨骼和骨骼肌块中的钙也会丢失。我们计划调查两组2型糖尿病女性在减肥过程中骨矿物质和骨骼肌的丢失，一组采用低热量饮食减肥，另一组采用胃旁路手术减肥。需要检验的假设是，随着体重的下降：1)两组人的骨骼肌都会失去；2)如果受试者补充适当的钙和维生素D，骨钙不会丢失；3)骨转换的生化指标会升高；4)手术组的胃肠道钙吸收会受到损害；5)生活质量会随着体重的减少而改善。我们将研究BMI在35到40之间，年龄在25到45岁之间的绝经前糖尿病妇女。使用核心A和B生化标记物测量身体成分和生活质量将在基线、6个月、一年和两年进行。将比较两组患者这些参数的变化以及血糖控制(HgbA1c)、血压和血脂的改善情况。核心C将用于数据存储、数据分析和结果统计评估。在美国，严重肥胖的糖尿病女性减肥尝试的发病率很高，随着减肥手术干预的增加，是否会对骨骼和肌肉产生不利影响，是估计此类尝试的风险-收益比的重要因素。目前还没有关于2型糖尿病患者胃旁路术后骨量丢失和肌肉质量的足够数据，因此这项建议是及时的，具有公共卫生意义。

Severely obese women (BMI 35 to 40) with type 2 diabetes mellitus have an increased skeletal mass. They also have an increased fat-free mass, presumably including increased skeletal muscle. These women are continually attempting to lose weight in order to improve their diabetes control. Attempts at weight loss have generally been carried out medically in the past, but severely obese women are undergoing bariatric surgery more and more frequently. With weight loss, by whatever means, medical or surgical, fat mass is lost. In addition, there is some evidence that calcium from bone and skeletal muscle mass is also lost. We plan to investigate the loss of bone mineral and skeletal muscle during weight loss in two groups of women with type 2 diabetes, one group losing weight on a hypocaloric diet and another group losing weight with gastric by-pass surgery. The hypotheses to be tested are that, with weight loss: 1) skeletal muscle will be lost in both groups; 2) bone calcium will not be lost if subjects are appropriately supplemented with calcium and vitamin D; 3) biochemical markers of bone turnover will be elevated; 4) gastrointestinal calcium absorption will be impaired in the surgical group; 5) quality of life will improve in proportion to amount of weight loss. We will study pre-menopausal diabetic women with a BMI range of 35 to 40, aged 25 to 45 years. Measures of body composition using Core A&B biochemical markers, and quality of life will be taken at baseline, 6 months, one year, and two years. The two groups will be compared for changes in these parameters and also for improvement in glucose control (HgbA1c), blood pressure, and blood lipids. Core C will be used for data storage, data analysis, and statistical evaluation of results. With the great incidence of weight loss attempts in this country by severely obese diabetic women, and with the increasing bariatric surgery interventions, whether adverse effects on bone and muscle occur is important in estimating the risk-benefit ratio of such attempts. There are no adequate data on bone loss and one on muscle mass in response to gastric by-pass in type 2 diabetic patients, so that the proposal is timely and has public health importance.