双能X线吸收法体脂分析在正常体重代谢性肥胖的应用

Application of dual-energy X-ray absorptiometry in determining body fat percentage reference in subjects with metabolic obesity in spite of body weight within normal range

目的 调查合肥地区汉族正常体重代谢性肥胖（MONW）的流行情况及影响因素，探讨双能X线吸收法（DXA）体脂分析对MONW的诊断切点。方法 入选体重指数（BMI）介于18.5～23.9 kg/m2的合肥地区成人660名，测定其血压、腰围、血糖、血脂、血清胰岛素及高敏C反应蛋白（hsCRP）；DXA检测体脂含量（%BF），以受试者工作曲线（ROC）评价%BF对MONW的诊断价值；MONW的诊断根据HOMA胰岛素抵抗指数（HOMA-IR）确定；疾病危险度分析用logistic回归（OR值）。结果 （1）BMI〈24 kg/m2的研究人群，男性MONW检出率为11.41%（46/403）, 女性MONW检出率为16.34%（42/257）（P〉0.05）。（2）Logistic回归分析显示，男性MONW的发生与腰围（OR=2.35, P〈0.01）、%BF（全身, OR=3.65，P〈0.01）、%BF（腹部, OR=26.07, P〈0.01）、hsCRP（OR=2.09, P=0.011）、甘油三酯（OR=5.92, P=0.001）、低密度脂蛋白胆固醇（OR=13.65, P=0.009）相关；女性MONW 的发生与腰围（OR=1.32, P=0.045）、%BF（全身, OR=1.73, P〈0.01）、%BF（腹部, OR=8.43, P〈0.01）、hsCRP（OR=2.15, P=0.039）、甘油三酯（OR=9.12, P〈0.01）、低密度脂蛋白胆固醇（OR=2.64, P=0.005）及高密度脂蛋白胆固醇（OR=0.020, P〈0.01）相关。（3）根据ROC曲线将%BF≥25%（男）和%BF≥35%（女）者作为MONW诊断切点。结论 成人汉族人群中MONW比较常见，MONW的发生与腰围、血脂、hsCRP及%BF相关，男性体脂含量≥25%和女性体脂含量≥35%可分别作为诊断MONW的参考切点，DXA法体脂分析对MONW具有一定诊断价值。

Objective To investigate the prevalence and risk factors of metabolic obesity with normal weight（MONW） in Han nationality adult population, and to identify the cut-off points of body fat percentage（%BF） by dual-energy X-ray absorptiometry（DXA） for defining MONW. Methods Six hundred and sixty subjects （403 men and 257 women） with body mass index（BMI） ranged from 18.5 to 23.9 kg/m2 were recruited into this study. Waist circumference（WC）, blood pressure（BP）, BMI, and %BF were measured. Serum concentrations of glucose, triglycerides（TG）, total cholesterol（TC）, high-density lipoprotein-cholesterol（HDL-C）, low-density lipoprotein-cholesterol（LDL-C）, serum insulin, and high-sensitivity C-reactive protein（hsCRP） were tested. Those within the highest quartile in the homeostasis model assessment of insulin resistance （HOMA-IR） with a normal BMI between 18.5 and 23.9 kg/m2 were classified as MONW. Results The prevalence of MONW was 11.34% for men and16.34% for women amongst normal-weight subjects, there was no significant different between men and women in the prevalence（P〉0.05）. Multivariable Logistic regression analysis showed that TG（OR=5.92, P=0.001）, LDL-C（OR=13.65, P=0.009）, hsCRP（OR=2.09, P=0.011）, WC（OR=2.35, P〈0.01）, %BF（total, OR=3.65, P〈0.01） and %BF（abdominal, OR=26.07, P〈0.01） were the risk factors of MONW amongst men. For women, TG（OR=9.12, P〈0.01）, LDL-C（OR=2.64, P=0.005）, HDL-C（OR=0.020, P〈0.01）, hsCRP（OR=2.15, P=0.039）, WC（OR=1.32, P=0.045）, %BF（total, OR=1.73, P〈0.01） and %BF（abdominal, OR=8.43, P〈0.01） were the risk factors of MONW. The cut-off points of %BF for diagnosing MONW by ROC were %BF≥25% for men, %BF≥35.0% for women. Conclusion MONW is quite common in Han nationality adult population;.%BF,WC, hsCRP and lipid profiles were independently associated with MONW %BF≥25% for men, %BF≥35.0% for women can be used as reference cut-off.point for diagnosing MONW.