Nelson Tracy L, Bessesen Daniel H, Marshall Julie A
Department of Health and Exercise Science, Colorado State University, CO 80523, USA.
Diabetes Metab Res Rev. 2008 Jan-Feb;24(1):33-40. doi: 10.1002/dmrr.747.
To determine if dual-energy X-ray absorptiometry (DXA) measures of trunk fat, a user-defined abdominal region of interest (ROI) and waist circumference (WC) differ in their association with insulin sensitivity among Hispanics and non-Hispanic whites (NHW) or explain any ethnic differences in insulin sensitivity.
A cross-sectional study of data collected (1997-98) as part of the longitudinal San Luis Valley Diabetes Study was utilized. There were 664 non-diabetic participants including 349 women (220 NHW, 139 Hispanic) and 305 men (197 NHW, 108 Hispanic), average age 63 years. Measurements included body mass index, WC and DXA measures of total and abdominal fat. Fasting glucose and insulin were used to estimate insulin sensitivity using the QUICKI index. A 2-h oral glucose tolerance test was used to classify participants with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT).
Among women with NGT, Hispanics had lower insulin sensitivity, with DXA trunk fat explaining the most variance in QUICKI and 54% of the ethnic difference in QUICKI after adjusting for total body fat and lean mass. Among men with NGT, there were no differences between Hispanics and NHW in insulin sensitivity or any differences in the association of the abdominal fat measures with insulin sensitivity. Among men and women with IGT, the fat distribution variables explained little variance in QUICKI.
DXA measures of trunk fat provide additional information over WC and the DXA abdominal ROI measure about ethnic differences in insulin sensitivity between older Hispanic and NHW women with NGT.
为了确定双能X线吸收法（DXA）测量的躯干脂肪、用户定义的腹部感兴趣区域（ROI）和腰围（WC）与西班牙裔和非西班牙裔白人（NHW）胰岛素敏感性之间的关联是否存在差异，或者解释胰岛素敏感性方面的任何种族差异。
利用作为纵向圣路易斯谷糖尿病研究一部分收集的数据（1997 - 1998年）进行横断面研究。共有664名非糖尿病参与者，包括349名女性（220名NHW，139名西班牙裔）和305名男性（197名NHW，108名西班牙裔），平均年龄63岁。测量指标包括体重指数、WC以及DXA测量的全身和腹部脂肪。使用空腹血糖和胰岛素通过QUICKI指数估计胰岛素敏感性。采用2小时口服葡萄糖耐量试验对葡萄糖耐量正常（NGT）或葡萄糖耐量受损（IGT）的参与者进行分类。
在NGT女性中，西班牙裔胰岛素敏感性较低，DXA躯干脂肪在调整全身脂肪和瘦体重后解释了QUICKI中最大的变异以及QUICKI中54%的种族差异。在NGT男性中，西班牙裔和NHW在胰岛素敏感性方面没有差异，腹部脂肪测量指标与胰岛素敏感性的关联也没有差异。在IGT男性和女性中，脂肪分布变量在QUICKI中解释的变异很小。
对于年龄较大的NGT西班牙裔和NHW女性，DXA测量的躯干脂肪比WC和DXA腹部ROI测量提供了更多关于胰岛素敏感性种族差异的信息。
