体重指数筛查中老年人糖尿病前期和糖尿病的适宜切点研究

Optimal cut-off points of BMI for screening of pre-diabetes and diabetes in middle-aged and elderly people

目的确定一个适用于筛查中老年人糖尿病前期(Pre-DM)和糖尿病(DM)的体重指数(BMI)切点。方法从长沙市某体检中心2014年体检人群中纳入研究对象2 621例,分别根据ADA(2010)和WHO(1999)标准诊断DM/Pre-DM。计算BMI诊断DM/Pre-DM的受试者工作特征曲线下面积(AUROC)及不同BMI切点(21~28)kg/m^2筛查DM或DM和Pre-DM的敏感性、特异性和约登指数。结果研究对象平均年龄(53.7±11.1)岁,平均BMI(24.2±2.9)kg/m^2,DM患病率6.9%,Pre-DM患病率8.1%(WHO)、24.3%(ADA)。BMI诊断Pre-DM/DM的准确性较低(AUROC<0.7),不同BMI切点下约登指数均较小(3.6%~29.2%),但敏感性波动较大(12.8%~95.0%);总人群BMI切点24 kg/m^2对应最大约登指数,但在该切点下女性超过一半Pre-DM/DM患者漏诊(54.6%);男女性BMI切点分别为23 kg/m^2和22 kg/m^2时,敏感性接近80%,与切点24kg/m^2比较,特异性减小,约登指数差异无统计学意义。结论 BMI单独用于诊断中老年人Pre-DM/DM的准确性较低,适宜的筛查切点应降低,男女性分别为23 kg/m^2和22 kg/m^2。

Objective To identify the BMI cut-off points most practical for screening pre-diabetes （Pre-DM） and diabetes （DM） in middle-aged and older adults. Methods Totally 2,621 subjects who attended regular health examination in a physical examination center of Changsha in 2014 were included, And the participants were diagnosed with Pre-DM or DM using ADA criteria （2010） and WHO criteria （1999）, respectively. The area under ROC curve （AUC） for BMI diagnosis of Pre-DM or DM was calculated; as well as the sensitivity, specificity and Youden index under different BMI cut-off points （ranging from 21 to 28 kg/m2）. Results The mean age was （53.7 ± 11.1） years, and the mean BMI was （24.2 ± 2.9） kg/m2. The prevalence of DM were 6.9% and that of Pre-DM was 8.1% （WHO） or 24.3% （ADA）, respectively. The accuracy of BMI diagnosis of Pre-DM or DM was low （AUC 〈 0.7）, the sensitivity varied widely （12.8%-95.0%）, although Youden index varied minimally across BMI cut-point （3.6%- 29.2%）. The BMI cut-point with the highest Youden index was 24 kg/m2, but limited screening at this cut-point would miss almost half of Pre-DM/DM diagnosis in women （54.6%）. At BMI ≥ 23 kg/m2 for men and BMI/〉 22 kg/m2 for women, the sensitivity of screening Pre-DM or DM would approximately equal to 80%; compared with the cut-off point of 24 kg/m2, the specificity decreased, there was no significant difference in the Youden index. Conclusions BMI alone is not an effective indicator for diagnosis of Pre-DM or DM in middle-aged and older adults, and the optimal BMI cut-off points for screening Pre-DM/DM should be lowered to 23 kg/m2 for men and 22 kg/m2 for women.