绝经后女性的体成分与年龄和绝经的关系及其对不同部位骨密度的影响

目的 调查绝经后女性的体成分与年龄、绝经年龄、绝经年限和腰椎、髋部BMD之间的关系.方法 用双能X线骨密度仪测量919例绝经后女性的体成分、正位腰椎和髋部BMD.结果 下身脂肪量、全身脂肪量和全身瘦组织量与年龄、绝经年龄和绝经年限都相关(P＜0.05～0.01),但只有绝经年限进入体成分的多元逐步回归方程,采用复合或三次回归模型拟合优度最佳.体成分随绝经年限的延长有下降趋势.绝经10年以上女性的下身脂肪量和全身瘦组织量显著减少,分别较绝经年限5年以内女性下降8.6%和3.1%.所有部位的体成分与所测区域的BMD 均呈正相关(P＜0.05～0.01),控制体重变量后,仅有全身脂肪量与腰椎BMD 呈正相关(P＜0.05),而全身瘦组织量与髋部BMD 呈正相关(P＜0.05).多元逐步回归分析发现体成分是影响腰椎和髋部BMD的一个重要因素,但对腰椎BMD影响最大的是全身脂肪量,而对髋部BMD影响最大的是全身瘦组织量.BMD 越低者,全身脂肪量和全身瘦组织量也越低,组间比较有显著性差异.结论 绝经后女性的体成分与年龄、绝经年龄、绝经年限和腰椎、髋部BMD相关,其中,绝经年限对体成分的影响最大,体成分组分对BMD的影响存在部位差异.

Relationships of body composition with age and menopause and its effects on bone mineral density at various skeletal regions in postmenopausal women

Objective To investigate the relationships of body composition with age, menopausal age, years since menopause (YSM) and areal bone mineral density (BMD) at posteroanterior spine and hip in postmenopausal women.Methods Body composition and BMD at posteroanterior spine and hip were measured by dual-energy X-ray absorptiometry (DXA) in 919 postmenopausal women.Results Lower body fat mass (LF), whole fat mass (WF) and whole lean mass (WL) were all correlated with age, menopausal age and YSM (P＜0.05～0.01), while only YSM entered multiple stepwise regression equation of body composition and the goodness of fit in complex or cubic regression model was best.Body composition had a downward trend with YSM.LF and WL reduced significantly in the women with YSM over 10 years, which were lower 8.6% and 3.1% compared to those of the women with YSM within 5 years respectively.All regional body composition was positively correlated with all regional BMD (P＜0.05～0.01).After controlling body weight, only WF was related to BMD at posteroanterior spine (P＜0.05), while WL was related to BMD at hip (P＜0.05).Multiple stepwise regression analysis revealed that body composition was an important variable that affected the BMDs at lumbar spine and hip and WF was the main determinant of BMD at lumbar spine while WL was the main determinant of BMD of hip.Lower BMD, lower WF and WL.The difference of WF and WL was significant among different BMD groups.Conclusions Body composition is related with age, menopausal age, YSM and BMD at posteroanterior spine and hip in postmenopausal women; YSM is the most important influencing factor to body composition; there is regional difference in the effects of body composition components on BMD.