Mayer-Davis E J, Monaco J H, Hoen H M, Carmichael S, Vitolins M Z, Rewers M J, Haffner S M, Ayad M F, Bergman R N, Karter A J
Department of Public Health Sciences, Bowman Gray School of Medicine, Wake Forest University, Winston-Salem, NC 27157-1063, USA.
Am J Clin Nutr. 1997 Jan;65(1):79-87. doi: 10.1093/ajcn/65.1.79.
From the Insulin Resistance Atherosclerosis Study (IRAS), 1173 men and women of African-American, non-Hispanic white, and Hispanic ethnicity with no history of diabetes were included in an evaluation of the cross-sectional relation of habitual dietary fat intake with insulin sensitivity (SI) as assessed by minimal-model analysis of a 12-sample, insulin-modified frequently sampled intravenous-glucose-tolerance test. Dietary intake was measured by a food-frequency interview modified to enhance sensitivity to food choices within the three ethnic groups. Percentage of energy from total fat was associated with rank of SI (SI(rank); r = -0.06, P = 0.03), with log fasting insulin (r = 0.10, P < 0.001), and with BMI (r = 0.10, P < 0.001). Multiple-linear-regression models included SI(rank) as the dependent variable, dietary fat (g/d) as the primary independent variable adjusted sequentially for total energy, other covariates, body mass index, and waist-hip circumference ratio (WHR). For all subjects combined, total fat intake was inversely related to SI(rank), but this association was not significant (P = 0.14) and was attenuated by adjustment for body mass index and WHR (P = 0.44). The association of total fat (g/d) with SI(rank) differed significantly (P < 0.01) for obese compared with nonobese individuals. Higher fat intake was associated with lower SI(rank) among obese (beta = -1.40, P = 0.03) but not among nonobese persons (beta = 0.16, P = 0.80). Among the obese (body mass index < or = 63), adjustment for body mass index largely accounted for the observed association of dietary fat with SI(rank). These findings were generally consistent for monounsaturated, polyunsaturated, and saturated fats. Among individuals already at increased risk for non-insulin-dependent diabetes mellitus because of obesity, high intake of dietary fat may worsen insulin sensitivity. This effect may be mediated by the relation of dietary fat to obesity.
胰岛素抵抗动脉粥样硬化研究（IRAS）纳入了1173名非裔美国人、非西班牙裔白人及西班牙裔的男性和女性，他们均无糖尿病史，研究通过对12次采样的胰岛素修饰频繁采样静脉葡萄糖耐量试验进行最小模型分析，评估习惯性膳食脂肪摄入量与胰岛素敏感性（SI）之间的横断面关系。膳食摄入量通过改良的食物频率访谈进行测量，以提高对三个种族群体内食物选择的敏感性。来自总脂肪的能量百分比与SI等级（SI(rank)）相关（r = -0.06，P = 0.03），与空腹胰岛素log值（r = 0.10，P < 0.001）相关，与体重指数（r = 0.10，P < 0.001）相关。多元线性回归模型以SI(rank)作为因变量，膳食脂肪（克/天）作为主要自变量，并依次对总能量、其他协变量、体重指数和腰臀围比（WHR）进行调整。对于所有受试者，总脂肪摄入量与SI(rank)呈负相关，但这种关联不显著（P = 0.14），且在调整体重指数和WHR后减弱（P = 0.44）。肥胖个体与非肥胖个体相比，总脂肪（克/天）与SI(rank)的关联差异显著（P < 0.01）。在肥胖者中，较高的脂肪摄入量与较低的SI(rank)相关（β = -1.40，P = 0.03），而在非肥胖者中则不然（β = 0.16，P = 0.80）。在肥胖者（体重指数≤63）中，对体重指数的调整在很大程度上解释了观察到的膳食脂肪与SI(rank)之间的关联。这些发现对于单不饱和脂肪、多不饱和脂肪和饱和脂肪总体上是一致的。在因肥胖而已经处于非胰岛素依赖型糖尿病风险增加的个体中，高膳食脂肪摄入量可能会使胰岛素敏感性恶化。这种效应可能由膳食脂肪与肥胖之间的关系介导。
