摘要目的 探讨生育期正常糖代谢肥胖女性体成分、胰岛β细胞功能变化及其对骨密度的影响.方法 根据体重指数(BMI)将95例生育期正常糖代谢女性分为4组:非肥胖组(BMI＜23,20例)、超重组(23≤BMI＜25,20例)、Ⅰ度肥胖组(25≤BMI＜30,28例)和Ⅱ度肥胖组(BMI≥30,27例).身体各部位骨密度和脂肪、瘦组织质量采用双能X线骨密度仪检测,并行静脉葡萄糖耐量试验(IVGTT);计算胰岛素曲线下面积(AUCins)、胰岛素急性分泌时相(AIR)评估早期胰岛素分泌功能,以稳态模型B细胞功能指数(HOMA2-%B)、胰岛素抵抗指数(HOMA2-IR)估测β细胞功能和胰岛素抵抗情况.结果 随BMI增加,上肢、下肢、躯干、全身脂肪质量、瘦组织质量和骨密度均递增(P＜0.05),以脂肪增加更为显著;IVGTT第0分钟胰岛素(IVGTTins0)、MR、AUCins、HOMA2-%B、HOMA2-IR亦呈增加趋势(P＜0.01).上肢、下肢、躯干、全身骨密度与BMI、空腹血糖、对应部位瘦组织质量和(或)脂肪质量呈正相关(P＜0.05);躯干、全身骨密度分别与IVGTTins0、AIR、AUCins和HOMA2-IR呈正相关(P＜0.05).多元同归分析显示HOMA2-%B、HOMA2-IR与骨密度具有线性关系;若引入体成分指标,HOMA2值则不能进人方程.偏相关分析显示,控制体成分因素后,β细胞功能指标与身体各部位骨密度均无相关.结论 以脂肪增加为主的肥胖人群所伴随的胰岛素抵抗或β细胞功能代偿对骨密度益处较小,其作用可能是体成分改变的间接反映.体成分尤其瘦组织是肥胖女性骨密度最主要的决定因素.

abstractsObjective To investigate effects of changes in body composition and pancreas islet β-cell function on bone mineral density(BMD)in obese women with normal glucose metabolism at child-bearing age.Methods Ninety-five obese women with normal blood glucose at child-bearing age were recruited for the study,20 in non-obese group with body mass index(BMI)less than 23,20 in overweightgroup with BMI equal to or more than 23 and less than 25.28 in obesity Ⅰ group with BMI equal to or more than 25 and less than 30.and 27 in obesity Ⅱ group with BMI equal to or more than 30.Their BMD,body fat and lean mass were measured with by dual energy X-ray absorptiometer(DEXA),and intravenous -glucose tolerance test(IVGTT)was performed.Area under the Curve of insulin(AUCins)and acute jnsulin response(AIR)phase were calculated to assess their early insulin secretion.Homeostasis model assessment β-cell function index(HOMA2-%B)and homeostasis model insulin resistance index(HOMA2-IR)were used to assess their β-cell function and insulin resistance.Results Fat and lean mass in the upper and lower extremities.trunk and whole body and BMD in those women increased with increasing of their BMI(P＜0.05),particularly in fat mass.as well as their otller parameters including plasma insulin level at zerominute of IVGTT(IVGTTins0),AUCins.HOMA2-%B and HOMA2.IR(all P＜0.01).BMD in the upper and lower extremities,trunk and whole body showed a positive correlation with BMI,FPG,lean mass and/or fat mass.respectively(P＜0.05).BMD of the trunk and whole body also had a positive correlation with TVGTTins0,AIR,AUCins and HOMA2-IR.respectively(P＜0.05).Results of multivariate linear regression analysis showed that HOMA2-%B and HOMA2-IR correlated with BMD in a linear pattern.As the vailable body composition was added to the regression model.HOMA2 parameters would be removed from the model.Results of partial correlation analysis showed that islet β-cell function did not correlate with BMD after controlling body composition factors.Conclusions Insulin resistance or islet β-cell function compensation accompanied in obese women with main increase in fat mass have little benefit for their BMD,which may reflect indirectly their change in body compositions.Body composition,especially lean nlass,is the most important determinants of BMD in obese women.