Table 2

Linear regression models for measures of insulin action using backward stepwise variable selection controlling for age, sex, and waist circumference

Parameter estimateSEMFP
SI model: R2SI = 0.63, P < 0.0001
    Factor 4: Large neutral amino acids and uric acid−0.1230.02721.41<0.0001
    Waist circumference (cm)−0.0140.00316.280.0001
    Factor 8: Glycine and serine0.0910.02513.570.0005
    Factor 7: Glutamate/Glutamine (ketones and glucose)−0.0930.02711.950.001
AIRg model: R2AIRg = 0.28, P < 0.0002
    Factor 2: Fatty acids and by-products of fatty acid oxidation−0.0880.0434.070.048
DI model: R2DI = 0.39, P < 0.0001
    Factor 4: Large neutral amino acids and uric acid−0.1450.04410.560.002
    Factor 2: Free fatty acids and by-products of fatty acid oxidation−0.1310.0468.060.006
    Age (years)−0.0140.0065.920.018
    Factor 5: Medium-chain acylcarnitines and glucose−0.0920.0424.830.032
  • Metabolite factors are those that remained significant in multivariable regression models. R2 values reflect values for models presented and include effects of age, sex, and waist circumference. Only significant predictors are presented and individual R2 values are discussed in text.