12285例体检者局部脂肪含量与骨密度的相关性研究

Correlational study between regional fat content and the bone mineral density in 12285 healthy subjects

目的了解腰椎周围及髋部周围脂肪比例与骨密度的关系,探讨局部脂肪含量对骨密度检测值的影响。方法收集12285例正常体检人群双能X线骨密度(DEXA)检测的骨密度数据(腰椎和髋部),同时收集每人"骨密度局部模式"所检测的"腰椎周围"及"髋部周围"脂肪比例值数据,按照性别、体重指数(BMI)对本组检测人员分组,采用单因素方差分析和多元线性回归统计方法,回顾分析局部脂肪比例与骨密度之间的相关性。结果单因素方差分析:在髋部脂肪比例高的组中,各组骨密度的平均值均较低。男性髋部和腰椎骨密度在腰周脂肪比例高的组别中平均值较高,而女性腰椎骨密度在腰周脂肪比例高的组中平均值较低,髋部的骨密度则没有明显的改变。多元线性回归分析:女性组:骨密度与身高(r=0.276～0.497)和体重(r=0.216～0.526)正相关,与年龄负相关(r=-0.730～-0.454),与髋部周围脂肪比例负相关(r=-0.369～-0.352),与腰椎周围脂肪比例负相关(r=-0.400～-0.245)。在多元回归分析中,控制其他变量后,腰椎骨密度和腰椎周围脂肪比例无统计学上的相关性。腰椎骨密度和髋部周围脂肪比、髋部骨密度和两个部位的脂肪比均呈负相关,并且在BMI高的组中,负相关性较为显著,其中髋部脂肪比和腰椎骨密度负相关性最为显著(r=-0.220～-0.194)。男性组:骨密度与身高(r=0.139～0.388)和体重呈正相关,与年龄相关性差(r=-0.494～0.077),与髋部周围脂肪比例负相关(r=-0.400～-0.216),与腰椎周围脂肪比例负相关(r=-0.329～-0.223)。在多元回归分析中,控制其他变量后,腰椎骨密度和腰椎周围脂肪比例在BMI<20 kg/m2组中呈显著的正相关(r=0.294),在其它组中没有显著的相关性。腰椎骨密度和髋部周围脂肪比、髋部骨密度和两个部位的脂肪比例呈负相关,其中腰椎骨密度和髋部周围脂肪比的负相关性最为显著(r=-0.207～-0.108),并且在BMI低的组中,负相关程度较高。结论脂肪含量对骨密度有显著的影响,局部脂肪比例增加骨密度下降显著(成年女性BMI指数越高相关性越高);脂肪分布对骨密度影响明显,髋部脂肪比(皮下脂肪为主)与腰椎骨密度的负相关性最显著。

Objective To investigate the correlation between the fat percentage around the lumbar vertebrae and the hip and bone mineral density（ BMD）,and to discuss the effect of regional fat content on BMD. Methods A total of 12285 subjects of normal people receiving physical examination were collected. BMD of the lumbar vertebrae and the hip was detected using DEXA. The fat percentage of the trunk and the legs was also detected using local model of DEXA. All subjects were grouped by gender and BMI.One-way analysis of variance and multiple linear regression analysis were performed to analyze the correlation between regional fat percentage and BMD. Results The results of one-way analysis of variance revealed that in groups with higher hip fat percentage,the average BMD was lower. The average BMD of the lumbar vertebrae and the hip in groups with higher trunk fat percentage in males was higher. The average BMD of the lumbar vertebrae in groups with higher trunk fat percentage in females was lower,while no significant changes of the hip BMD were observed. The results of multiple linear regression analysis showed that,in female groups,BMD was positively correlated with height（ r = 0. 276- 0. 497） and weight（ r = 0. 216- 0. 526）,while negatively correlated with age（ r =- 0. 7300 to- 0. 454）,the trunk fat percentage（ r =- 0. 400to- 0. 245）,and the leg fat percentage（ r =- 0. 369 to- 0. 352）. After controling other variables,the lumbar BMD showed no statistical correlation with the trunk fat percentage. However,remarkable negative correlation existed between the lumbar BMD and the trunk fat percentage,as well as the hip BMD and regional fat percentage,which was even more remarkable as BMI rising. Therefore,the negative correlation between the lumbar BMD and the trunk fat percentage was most notable. In male groups,BMD was positively correlated with height（ r =0. 139- 0. 388） and weight（ r = 0. 139- 0. 388）,while negatively correlated with age（ r =- 0. 494- 0. 077）,trunk fat percentage（ r =- 0.329 to- 0.223）,and the leg fat percentage（ r =- 0.400 to- 0.216）. In multiple linear regression models,after controling other variables,the lumbar BMD presented notable positive correlation with the trunk fat percentage only when BMI 〈20kg /m2（ r =0.294）. And remarkable negative correlation also existed between the lumbar BMD and the trunk fat percentage,as well as the hip BMD and the regional fat percentage. The negative correlation between the lumbar BMD and the trunk fat percentage was most notable（- 0. 207 to- 0. 108）. The negative correlation was decreased along with the increase of BMI. Conclusion Fat content exerts notable influence in BMD. Along with the increase of local fat proportion,BMD decreases significantly. And the correlation is more notable in women with higher BMI index. Fat distribution also has obvious effect on BMD. The negative correlation between the hip fat proportion and the lumbar BMD is most remarkable.