Obesity Research Unit, Department of Medicine, Division of Endocrinology, Helsinki University Central Hospital, University of Helsinki, Biomedicum 1, Haartmaninkatu 8, PO Box 700, FIN-00029 HUCH, Finland.
Br J Nutr. 2013 May 28;109(10):1910-6. doi: 10.1017/S0007114512003698. Epub 2012 Aug 31.
The aim of the present study was to analyse the agreement of bioelectrical impedance analysis (BIA) compared with dual-energy X-ray absorptiometry (DXA) and MRI in estimating body fat, skeletal muscle and visceral fat during a 12-month weight loss intervention. A total of nineteen obese adults (twelve females, seven males) aged 20·2-48·6 years, mean BMI 34·6 (SE 0·6) kg/m², participated in the study. Body fat, skeletal muscle and visceral fat index were measured by BIA (Omron BF-500; Omron Medizintechnik) and compared with DXA (body fat and skeletal muscle) at baseline, 5 and 12 months, and with MRI (visceral fat) at baseline and 5 months. The subjects lost 8·9 (SE 1·8) kg (9·0 (SE 1·7) %) of body weight during the 12-month intervention. BIA, as compared to DXA, accurately assessed loss of fat (7·0 (SE 1·5) v. 7·0 (SE 1·4) kg, P= 0·94) and muscle (1·0 (SE 0·2) v. 1·4 (SE 0·3) kg, P= 0·18). While body fat was similar by the two methods, skeletal muscle was underestimated by 1-2 kg using BIA at each time point. Compared to MRI, BIA overestimated visceral fat, especially in males. BIA and DXA showed high correlations for kg fat, both cross-sectionally and longitudinally (r 0·91-0·99). BIA, compared with DXA and MRI, detected kg muscle and visceral fat more accurately cross-sectionally (r 0·77-0·87 and r 0·40-0·78, respectively) than their changes longitudinally (r 0·24-0·61 and r 0·46, respectively). BIA is at its best when assessing the amount or changes in fat mass. It is a useful method for measuring skeletal muscle, but limited in its ability to measure visceral fat.
本研究旨在分析生物电阻抗分析（BIA）与双能 X 射线吸收法（DXA）和磁共振成像（MRI）在估计 12 个月减肥干预期间体脂肪、骨骼肌和内脏脂肪的一致性。共有 19 名肥胖成年人（12 名女性，7 名男性）参与了这项研究，年龄 20.2-48.6 岁，平均 BMI 为 34.6（SE 0.6）kg/m²。基线、5 个月和 12 个月时，使用 BIA（欧姆龙 BF-500；欧姆龙医疗技术）测量体脂肪、骨骼肌和内脏脂肪指数，并与 DXA（体脂肪和骨骼肌）进行比较，基线和 5 个月时与 MRI（内脏脂肪）进行比较。在 12 个月的干预期间，受试者体重减轻了 8.9（SE 1.8）kg（9.0（SE 1.7）%）。与 DXA 相比，BIA 准确评估了脂肪（7.0（SE 1.5）v. 7.0（SE 1.4）kg，P=0.94）和肌肉（1.0（SE 0.2）v. 1.4（SE 0.3）kg，P=0.18）的减少。虽然两种方法测量的体脂肪相似，但 BIA 在每个时间点都低估了 1-2kg 的肌肉。与 MRI 相比，BIA 高估了内脏脂肪，尤其是男性。BIA 和 DXA 对 kg 脂肪的横断面和纵向相关性均较高（r 0.91-0.99）。与 DXA 和 MRI 相比，BIA 更准确地横向（r 0.77-0.87 和 r 0.40-0.78）而不是纵向（r 0.24-0.61 和 r 0.46）检测 kg 肌肉和内脏脂肪的变化。BIA 在评估脂肪量或变化方面效果最佳。它是一种测量骨骼肌的有用方法，但在测量内脏脂肪方面能力有限。
