性别、年龄对成人BMI超重与肥胖诊断标准影响

目的探讨性别、年龄对体质指数(BMI)诊断标准的影响。方法采用78257名成人健康体检数据,以体脂率诊断结果为金标准,进行BMI诊断结果分析。结果BMI与体脂率呈中度相关(r=0.641,P<0.001),按性别分层后BMI与体脂率均呈高度相关(r=0.808,0.925,P<0.001);偏相关系数显示,性别对BMI与体脂率的相关系数影响较大而年龄因素影响较小;线性回归分析显示,≤30岁组BMI超重和肥胖切点男性分别为22和24.5,女性为19.5和22;>30岁组BMI超重和肥胖切点男性分别为24和27,女性为21和25;以体脂率诊断结果作为金标准,与BMI原诊断标准(简化的亚洲成人BMI标准)结果比较,Kappa值为0.379±0.003(P<0.001);与按性别、年龄划分的BMI诊断标准结果比较,Kappa值为0.588±0.002(P<0.001)。结论目前BMI在客观反映人体脂肪含量方面的缺陷很可能是由于其诊断切点未考虑性别和年龄等因素的影响所致。

Influences of gender and age on correlation of BMI and BF% in adult

ObjectiveTo explore the correlation between body mass index (BMI) and percentage of body fat(BF%) and the inpact of gender and age on the correlation. MetbodsData from 78, 257 participants in 2006 annual health screening were used for data mining, correlation analysis, linear regression and agreement analysis. Results There was a moderate correlation between BMI and BF% (r=0.641, P<0.001).However, close correlations in bothmale and female(r=0.808, r=0.925, P<0.001, respectively) were found.It suggested based on partial correlation coefficient that gender had much more inportant inpact on the correlation coefficient between BMI and BF% than age. The linear regression analysis suggested that the cut-off points of BMI for ovenv eight and obesity were 22 and 24.5 in male, 19.5 and 22 in female aged less than 30; 24 and 27 in male, 21 and 25 in female aged more than 30, respectively. The agreement rate was 59.2% when original diagnostic standard of BMI was used, with a Kappa coefficient of 0.379±0.003(P<0.001).The agreement rate was 73.6% when new diagnostic standard of BMI was used, with a Kappa coefficient of 0.588±0.002(P<0.001).Twice more ovenveightpopulation could be screened out by the new standard than the original one. ConclusionBMI would be a betterm easurement of body fatty ith new cut-off points established for different gender and age.