Gao Bo, Liu Yu, Ding Chao, Liu Shunli, Chen Xiaotian, Bian Xiaojie
Department of Clinical Nutrition, Nanjing University Medical School Affiliated Nanjing Drum Tower Hospital, Nanjing, Jiangsu, China.
Department of Gynecology and Obstetrics, The affiliated Obstetrics and Gynecology Hospital with Nanjing Medical University; Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu, China.
BMJ Open. 2020 Jul 23;10(7):e036335. doi: 10.1136/bmjopen-2019-036335.
Bioelectrical impedance analysis (BIA) is a simple and inexpensive method to estimate body composition. However, the accuracy of BIA is unknown. We aimed to assess the accuracy of BIA in estimating visceral fat area (VFA) in patients with gastric cancer.
This was a cross-sectional study comparing the accuracy of BIA in estimating VFA with the gold standard method measured by CT. VFA was measured in enrolled patients both by CT and BIA. VFA by CT at umbilical level ≥100 cm was considered as visceral obesity. Reliability between the two methods was assessed by intraclass correlation coefficient (ICC) and consistency was assessed by Bland-Altman method (95% limits of agreement). The area under the receiver operating characteristic curve (AUROC) was used to assess the performance of BIA in diagnosing visceral obesity.
The study was conducted in China.
From 1 January 2017 to 1 December 2018, a total of 157 patients diagnosed with gastric cancer were enrolled.
Overall, VFA by CT and BIA in patients was 84.39±46.43 cm and 71.94±22.44 cm, respectively. VFA estimated by BIA was positively correlated with VFA measured by CT using Pearson's test (r=0.650, p<0.001). Overall, ICC for the two methods was 0.675. The mean bias between the two measurements was 12.45±36.13 cm. The 95% limits of agreement ranged from -58.36 cm to 83.26 cm. The cut-off value for diagnosing visceral obesity by BIA was 81 cm (AUROC: 0.822, p<0.001, 95% CI 0.758 to 0.887).
VFA measured by BIA showed satisfactory reliability with that measured by CT. However, the absolute values of the two methods were not interchangeable. The cut-off value for VFA by BIA in diagnosing visceral obesity was 81 cm for patients with gastric cancer in the Chinese population.
生物电阻抗分析（BIA）是一种用于估计身体成分的简单且廉价的方法。然而，BIA的准确性尚不清楚。我们旨在评估BIA在估计胃癌患者内脏脂肪面积（VFA）方面的准确性。
这是一项横断面研究，比较BIA估计VFA的准确性与通过CT测量的金标准方法。对纳入研究的患者同时采用CT和BIA测量VFA。脐水平CT测量的VFA≥100 cm被视为内脏肥胖。两种方法之间的可靠性通过组内相关系数（ICC）进行评估，一致性通过Bland-Altman方法（95%一致性界限）进行评估。采用受试者工作特征曲线下面积（AUROC）评估BIA诊断内脏肥胖的性能。
该研究在中国进行。
2017年1月至2018年12月，共纳入157例诊断为胃癌的患者。
总体而言，患者CT测量的VFA和BIA测量的VFA分别为84.39±46.43 cm和71.94±22.44 cm。采用Pearson检验，BIA估计的VFA与CT测量的VFA呈正相关（r = 0.650，p<0.001）。总体而言，两种方法的ICC为0.675。两次测量之间的平均偏差为12.45±36.13 cm。95%一致性界限为-58.36 cm至83.26 cm。BIA诊断内脏肥胖的截断值为81 cm（AUROC：0.822，p<0.001，95%CI 0.758至0.887）。
BIA测量的VFA与CT测量的VFA显示出令人满意的可靠性。然而，两种方法的绝对值不可互换。在中国人群的胃癌患者中，BIA诊断内脏肥胖的VFA截断值为81 cm。
