Demura S, Sato S
Life-long Sports Core, Kanazawa Institute of Technology, Ishikawa, Japan.
J Sports Sci. 2007 May;25(7):823-33. doi: 10.1080/02640410600875010.
The aims of this study were to determine the validity of fat mass of the trunk as a predictor for visceral fat area at the umbilicus level and to develop equations to predict visceral fat mass at the umbilicus level using fat mass of the trunk measured by dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). The participants were 121 normal Japanese adults (69 males, 52 females). Another 60 volunteer adults (34 males, 26 females) were recruited for examination of cross-validity. Altogether, 41 adults (15 males, 26 females) in the original group and 19 adults (7 males, 12 females) in the cross-validity group received BIA measurement. We measured fat mass by DXA and the BIA system, which was a single-frequency BIA with 8-point contact electrodes, and visceral fat area by computed tomography. We observed significant correlations for visceral fat area in waist circumference (0.56) and fat mass of the trunk measured by DXA (0.64). There was no significant difference in fat mass of the trunk between the DXA and BIA systems, but the BIA system tended to provide an underestimate compared with DXA. With combined fat mass of the trunk measured by DXA and waist circumference as predictors, visceral fat area was estimated by equation (1) (R = 0.87, R(2) = 0.76, standard error of the estimate = 20.9 cm(2)). When substituting fat mass of the trunk measured by BIA into equation (1), there was no significant difference in visceral fat area between the reference and predicted values. An equation using fat mass of the trunk measured by BIA (equation 2) was obtained (R = 0.89, R(2) = 0.78, standard error of the estimate = 20.7 cm(2)), but a systematic error was found for the males. There was cross-validity in both equations. In conclusion, fat mass of the trunk is an effective predictor for the visceral fat area at the umbilicus level. Fat mass of the trunk measured by BIA might be a valid method to predict visceral fat, although further studies with larger samples taking into account the extent and type of obesity are required.
本研究的目的是确定躯干脂肪量作为脐水平内脏脂肪面积预测指标的有效性，并建立使用双能X线吸收法（DXA）和生物电阻抗分析（BIA）测量的躯干脂肪量来预测脐水平内脏脂肪量的方程。研究对象为121名正常日本成年人（69名男性，52名女性）。另外招募了60名志愿者成年人（34名男性，26名女性）进行交叉验证检查。原组中共有41名成年人（15名男性，26名女性）和交叉验证组中19名成年人（7名男性，12名女性）接受了BIA测量。我们通过DXA和BIA系统测量脂肪量，BIA系统是带有8点接触电极的单频BIA，通过计算机断层扫描测量内脏脂肪面积。我们观察到腰围与内脏脂肪面积之间存在显著相关性（0.56），DXA测量的躯干脂肪量与内脏脂肪面积之间也存在显著相关性（0.64）。DXA和BIA系统测量的躯干脂肪量没有显著差异，但与DXA相比，BIA系统往往低估了脂肪量。以DXA测量的躯干脂肪量和腰围作为预测指标，通过方程（1）估计内脏脂肪面积（R = 0.87，R² = 0.76，估计标准误差 = 20.9 cm²）。当将BIA测量的躯干脂肪量代入方程（1）时，参考值和预测值之间的内脏脂肪面积没有显著差异。得到了一个使用BIA测量的躯干脂肪量的方程（方程2）（R = 0.89，R² = 0.78，估计标准误差 = 20.7 cm²），但发现男性存在系统误差。两个方程都具有交叉验证性。总之，躯干脂肪量是脐水平内脏脂肪面积的有效预测指标。尽管需要进一步进行更大样本量的研究，同时考虑肥胖的程度和类型，但BIA测量的躯干脂肪量可能是预测内脏脂肪的有效方法。
