体成分对不同糖耐量水平男性骨密度的影响

Effect of body composition on bone mineral density in males with different glucose tolerance

目的:观察体成分对正常糖耐量(NGT)及2型糖尿病(T2DM)男性骨密度的影响及差异。方法:选择87例门诊及体检中心成年男性就诊者,其中57例为2型糖尿病(T2DM组),30例为糖耐量正常(NGT组),年龄35～64岁。采用双能X线骨密度仪测定腰椎前后位(AP)腰1至腰4、左侧股骨颈(FN)、左髋部总体(T-hip)及全身骨密度(T-BMD),同时测定体成分,计算出瘦体质量(LTM)、体脂量(FTM)、躯干体脂比(Tru-fat%)及总体脂比(Fat%)。分析体成分对2组研究对象骨密度的影响。结果:NGT组瘦体质量与股骨颈BMD正相关(r=0.411,P=0.024),T2DM组两者不相关;T2DM组体脂比与腰椎BMD负相关(r=-0.311,P=0.023),而NGT组两者无关。两组的体脂比均与全身BMD显著负相关。NGT组LTM是腰椎、股骨颈及髋部总体BMD的唯一独立影响因素(依次b=0.509,0.411,0.585,P<0.01或0.05,R2=0.169～0.342);T2DM组,LTM是腰椎(b=0.330,P<0.05,R2=0.109)和髋部BMD(b=0.462,P<0.01,R2=0.213)的唯一预测因素,而非股骨颈BMD的预测因素。结论:相对于正常糖耐量男性,2型糖尿病男性患者的瘦体质量对骨密度的保护作用减弱。无论糖耐量正常与否,成年男性体脂比例的增加不利于骨量的保护。

Objective To investigate the effect of body composition on bone mineral density（BMD） in males with different glucose tolerance.Methods A total of 87 male subjects aged 35～64 years were divided into 2 groups by glucose tolerance test,57 diagnosed T2DM and 30 with normal glucose tolerance（NGT）.BMDs of anteroposterior lumbar vertebrae（AP）,left femul neck（FN）,total hip（T-hip）,and total bone mineral density（TBMD）were measured by dual-energy-X-ray absorptiometry（DEXA）.Body composition was also measured by DEXA,while fat tissue mass（FTM）,lean tissue mass（LTM）,percentage of truncal fat（Tru-fat%） and total fat（Fat%） were computed.The effect of body composition on the BMD of the 2 groups was analyzed.Results LTM and FN-BMD had a positive correlation in the NGT group,but no correlation in the T2DM group.The percentage of fat showed a negative relationship with the BMD of AP in the T2DM group,but not in the NGT group.The percentage of fat and total BMD had a negative association in both the NGT and the T2DM groups.In the NGT group,LTM was the independent predictor of BMD of AP,FN and hip（b=0.509,0.411,and 0.585;P〈0.01 or 0.05;R^2=0.169～0.342）.In the T2DM group,LTM was the independent predictor of BMD of AP（b=0.330,P〈0.05,R^2=0.109） and hip（b=0.462,P〈0.01,R^2=0.213）,but not FN.Conclusion LTM has an attenuated effect on the BMD in male patients with T2DM compared with patients with NGT.An increased percent of fat percent is harmful to preserve bone mass in male adults,regardless of normal glucose tolerance or T2DM.