社区老年人身体成分与骨折跌倒风险的相关性研究

The Correlation between body composition and the risk of fracture in the elderly in communities

目的评价老年人肌肉和脂肪含量指标与骨质疏松骨折风险(fracture risk)和跌倒风险(fall risk for older people-community)的关联性。方法选取上海市社区的215名老年人,测量身高、体重、腰围、臀围,并换算成体质指数(body mass index,BMI)和腰臀比(waist-to-hip ratio,WHR)。骨密度仪测量受试者的骨密度、肌肉含量和脂肪含量,计算得到肌肉质量指数(lean mass index,LMI)、四肢骨骼肌指数(appendicular skeletal muscle mass index,ASMI)、脂肪质量指数(fat mass index,FMI)及体脂率(fat percentage)等指标。应用ROC曲线及Logistic回归分析评价各指标与骨折、跌倒风险的关联强度。结果本研究中高骨折风险组老年人身体成分指标LMI、ASMI、FMI、体脂率较低,四肢脂肪/躯干脂肪比值较高,是骨折风险的独立因素,ROC曲线下面积(area under the curve,AUC)差异均有统计学意义(P<0.05)。调整了年龄、性别及BMI后,高体脂率、骨质疏松、低握力比正常者的骨折风险高1.030、6.035及2.044倍。高跌倒风险组老年人腰臀比、体脂率、四肢脂肪/躯干脂肪比值较高。腰臀比WHR是跌倒风险的独立相关因素。调整后骨质疏松和低步速比正常者的跌倒风险高4.357倍和3.167倍。结论LMI、ASMI、FMI、体脂率是骨折风险的相关因素,腰臀比、步速是跌倒风险的相关因素。

Objective To evaluate the correlation between muscle and fat content indexes and osteoporotic fracture risk and fall risk for older people in communities in the elderly.Methods A total of 215 elderly people in the Shanghai community were selected.Height,weight,waist circumference,and hip circumference were measured and converted into body mass index(body mass index,BMI kg/m^(2))and waist-to-hip ratio(WHR).Bone mineral density(BMD),muscle content,and fat content were measured with a bone densitometer.Muscle mass index(lean mass/m^(2),LMI),limb skeletal muscle index(appendicular skeletal muscle mass/m^(2),ASMI),fat mass index(fat mass/m^(2),FMI),and body fat percentage(fat percentage)were calculated.ROC curves and logistic regression analysis were applied to evaluate the strength of the association between the indexes and the risk of fracture and falls.Results In this study,body composition indexes LMI,ASMI,FMI,body fat rate,and the limb/body fat ratio in the high fracture risk group were lower,which were the independent factors of high fracture risk.The area under the ROC curve(area under the curve,AUC)was statistically significant(P<0.05).After adjusting for age,sex,and BMI,the fracture risk with high body fat rate,osteoporosis,and low grip strength were 1.030,6.045,and 2.044 times higher than normal.The WHR,body fat rate,and limb/trunk fat ratio were higher in the high fall risk group.The WHR was an independent related factor of fall risk.Osteoporosis and low walking speed were 4.357 times and 3.167 times higher than that of normal people.Conclusion LMI,ASMI,FMI,and body fat rate are related with fracture risk.WHR and walking speed are correlated with fall risk.