双能X线吸收法和生物电阻抗法测量成年超重/肥胖人群体脂率一致性分析

Comparison of consistency in measurement of body fat percentage by dual-energy X-ray ;absorptiometry and multi-frequency bioelectrical impedance analysis in overweight and obese ;adults in China

目的：分析生物电阻抗（MF-BIA）法和双能X线吸收（DXA）法测量成年超重/肥胖人群体脂率的一致性，并建立MF-BIA法校正预测模型。方法招募志愿成年超重/肥胖者1323人，分别采用MF-BIA法和DXA法测定受试者的体脂率，分析两方法测量结果的一致性，并建立MF-BIA法校正预测模型。结果成年男女性超重/肥胖的MF-BIA法与DXA法测量体脂率差值分别为-6.5%、-4.3%和-2.5%、0.5%，差异均有统计学意义（均P＜0.01），其体脂率的组内相关系数分别为0.746、0.807和0.628、0.674，差异均有统计学意义（均P＜0.01）。MF-BIA法校正预测模型包括超重男性人群：体脂率（DXA法）＝13.425＋0.719×体脂率（MF-BIA法）；肥胖男性人群：体脂率（DXA法）＝12.572＋0.741×体脂率（MF-BIA法）；超重女性人群：体脂率（DXA法）＝9.785＋0.802×体脂率（MF-BIA法）；肥胖女性人群：体脂率（DXA法）＝20.348＋0.532×体脂率（MF-BIA法）。结论 MF-BIA法和DXA法测量我国成年超重/肥胖人群体脂率一致性较差，使用MF-BIA法测量体脂率需进行校正。

Objective To compare the consistency in the measurement of percentage of body fat（PBF） by multi-frequency bioelectrical impedance analysis （MF-BIA） and dual energy X-ray absorptiometry（DXA）in overweight and obese adults in China,and provide evidence for the accurate MF-BIA application in China. Methods A total of 1 323 overweight/obese adults aged 22-55 years were recruited in this study. All the subjects received PBF measurement by both MF-BIA and DXA. The consistency in PBF measurement by MF-BIA and DXA was evaluated by using interclass correlation coefficients（ICC）,then the correction prediction models was established. Results The differences in PBF measurement in male subjects and female subjects between MF-BIA and DXA were statistical significant （all P〈0.01）,the mean difference values were-6.5% for overweight males and -4.3% for obese males,-2.5% for overweight females and 0.5% for obese females, respectively. The difference in ICC of PBF between MF-BIA and DXA measurement were statistically significant in all subgroups （P〈0.01）. The ICC was 0.746 for overweight males,0.807 for obese males,0.628 for overweight females and 0.674 for obese females,respectively. The correction prediction models included：PBF（DXA）=13.425＋0.719 × PBF（MF-BIA）for overweight males;PBF（DXA）=12.572＋0.741×PBF（MF-BIA）for obese males;PBF（DXA）=9.785＋0.802× PBF （MF-BIA） for overweight females;PBF（DXA）=20.348＋0.532 × PBF（MF-BIA） for obese females. Conclusion The consistency in PBF measurement in overweight/obese adults by MF-BIA and DXA was poor in China. Correction should be conducted when MF-BIA is used in the measurement of PBF.