筛查2型糖尿病一级亲属的腹型肥胖测量指标适宜切点分析

Values of abdominal obesity indicators and their optimal cutoff points in screening type-2 diabetes mellitus in the first-degree adult relatives of diabetic patients

目的肥胖,尤其是腹型肥胖是心血管疾病和糖尿病的重要危险因素,但不同腹型肥胖指标(腰围、腰臀比、腰围身高比)预测糖尿病发病的作用仍有争议。文中旨在探讨应用腰围、腰臀比和腰围身高比预测中国人群2型糖尿病一级亲属中2型糖尿病发病的价值。方法选择2003年1月至2005年6月北京大学首钢医院内分泌科住院以及门诊确诊的2型糖尿病患者的一级亲属(非糖尿病)296人。采用1999年世界卫生组织(WHO)糖尿病专家委员会提出的糖尿病诊断标准,将受试者分为糖尿病组[n=59,空腹血糖≥7.0 mmol/L或者口服葡萄糖耐量试验(OGTT)2 h血糖或随机血糖≥11.1 mmol/L]、糖耐量减低(IGT)/空腹血糖受损(IFG)组[n=89,IFG:6.1 mmol/L≤空腹血糖≥7 mmol/L,OGTT 2 h血糖<7.8 mmol/L;IGT:空腹血糖<7.0 mmol/L,7.8 mmol/L≤OGTT 2 h血糖≥11.1 mmol/L]和正常糖耐量组(n=148,空腹血糖<6.1 mmol/L,OGTT 2 h血糖<7.8 mmol/L)。所有受试者均测量身高、体重、腰围、臀围、腰臀比、腰围身高比,并行75 g OGTT,测定空腹血糖及120 min血糖。利用受试者工作特征曲线比较不同腹型肥胖指标预测糖尿病发病的作用,并估计各腹型肥胖指标预测糖尿病发病的适宜切点值及其相应灵敏度和特异度。结果在男性中,IFG/IGT组、糖尿病组腰围[(96.75±8.94)、(93.73±8.48)cm]、臀围[(104.05±6.41)、(105.00±6.62)cm]、腰围/身高[(0.56±0.05)、(0.55±0.05)]较正常糖耐量组[(88.00±7.18)cm、(99.44±5.29)cm、(0.51±0.05)]显著增高,糖尿病组腰臀比较正常糖耐量组亦显著增高(P<0.05)。在女性中,糖尿病组腰臀比较正常糖耐量组明显增高[(1.06±1.36)vs(0.82±0.07),P<0.05]。男性腰围、腰臀比和腰围/身高预测糖尿病发病的ROC曲线下面积(95%CI)分别为0.706(0.575~0.837)、0.639(0.499~0.779)、0.709(0.579~0.839);女性分别为0.656(0.573~0.738)、0.611(0.527~0.696)、0.644(0.561~0.728);男性、女性腰围、腰臀比和腰围/身高预测糖尿病发病差异均无统计学意义(P>0.05)。男性腰围/身高预测糖尿病发病的最佳切点值、灵敏度和特异度分别为0.540,53.1%,82.8%;女性分别为0.505,68.4%,57.1%,在男性和女性中,腰围/身高最佳切点值为0.5。结论中国成人2型糖尿病一级亲属中,建议腰围/身高≥0.5切点值时进行糖尿病筛查。腰围/身高更适用于临床和公共卫生实践中用来指导腹型肥胖和糖尿病。

Objective Obesity, especially abdominal obesity, is a major risk factor of diabetes mellitus （DM） and cardiovascular diseases. However, the values of different indicators of abdominal obesity in predicting the risk of DM, such as waist circumference （WC） , hip circumference （HC） , waist-hip ratio （WHR） , and waist-height ratio （WHtR） , remain controversial. The aim of this study is to examine and compare the values of WC, WHR and WHtR in predicting type-2 DM in the first-degree adult relatives of DM patients in China. Methods This prospective cohort study included 296 first-degree relatives of the hospitalized type-2 DM patients in Shougang Hospital, 85 males and 211 females aged 30-78 years, and none with the history of glucose intolerance. According to the diagnostic criteria of DM published by the WHO Expert Committee on Diabetes Mellitus,we divided the patients into a DM group （n = 59,fasting blood glucose [FBG]≥7.0 mmol/L or glucose value after a 2-hour oral glucose tolerance test [ OGTT] or random blood glucose ≥11.1 mmol/L）,an impaired glucose tolerance （ IGT） / im-paired fasting glucose （IFG） group （n. = 89; IFG： 6.1 mmol/L≤FBG≥ 7 .0 mmol/L, 2 h OGTT glucose〈7.8 mmol/L; IGT： FBG〈 7.0 mmol/L,7.8 mmol/L≥2h OGTT glucose≥ 11.1 mmol /L） ,and a normal glucose tolerance （ NGT） group （n=148; FBG 〈 6 .1 mmol/L and 2h OGTT glucose〈7.8 mmol/L）. We obtained the height, weight, WC, HC, WHR and WHtR of the subjects, conducted a 75 g OGTT, and determined the levels of FBG and 120 min postprandial blood glucose. Using the ROC curve, we compared the roles of different abdominal obesity indexes in predicting the risk of DM as well as their appropriate cutoff values and corresponding sensitivity and specificity in prediction. Results Compared with the males of the NGT group,those of the IGT/IFG and DM groups showed significantly increased WC （ [ 88.00±7.18] vs [96.75±8.94] and [93.73±8.48] cm）, HC （ [ 99.44±5.29] vs [ 104.05±6.41 ] and [105.00±6.62] cm） , and WHtR （0.51±0.05 vs 0.56±0.05 and 0.55±0.05） （P〈0 .0 5 ） . The WHR was remarkably higher in both the males and females of the DM group than in those of the NGT group （0.93 ±0.05 and 1.06 ±1.36 m 0.89 ±0.07 and 0.82 ± 0 .0 7,P〈 0.05）. In the males, the AUC was 0.706 for WC （95% Cl： 0.575-0.837, P = 0.006） , 0.639 for WHR （95% CI： 0.499-0.779, P = 0.062） , and 0.709 for WHtR （95% CI： 0.5 7 9 -0 .8 3 9 , P = 0.005） , while in the females, the AUC was 0.656 for WC （95% CI： 0.573-0.738, P〈0.001）, 0.611 for WHR （95% CI： 0.527-0.696, P = 0 .0 1 2 ） , and 0.644 for WHtR （95% CI： 0.561-0.728, P = 0.001）. There were no statistically significant differences among the WC, WHR and WHtR of either the males or the females in predicting the risk of DM （P〉0.05）. The optimal cutoff value, sensitivity and specificity of WHtR were 0.54, 53.1% and 82.8% in the males and 0.505, 68.4% and 57.1% in the females. The optimal cutoff value of WHtR was 0.5 for both the males and females. Conclusion WHtR ≥0.5 is recommended as the appropriate cutoff value in screening type-2 diabetes among the first-degree adult relatives of DM patients in China. WHtR can be used in providing guidance for the control and prevention of abdominal obesity and DM in clinical and public health practice.