Table 1

Multiple linear regression analysis for associations of vitamin D with measures of insulin sensitivity/resistance and β-cell function

Outcome per unit increase in baseline 25(OH)DModel 1*Model 2Model 3
β (95% CI)PR2§β (95% CI)PR2§β (95% CI)PR2§
Insulin sensitivity/resistance measures
    IS-OGTT0.009 (0.007–0.011)<0.00010.100.008 (0.005–0.010)<0.00010.150.004 (0.002–0.007)0.00030.29
    HOMA-IR−0.010 (−0.012 to −0.007)<0.00010.11−0.008 (−0.010 to −0.005)<0.00010.15−0.003 (−0.006 to −0.001)0.0070.35
Beta-cell Function measures
    IGI/IR0.008 (0.005–0.011)<0.00010.120.007(0.004–0.011)0.00010.120.004 (0.0004–0.008)0.030.19
    ISSI-20.005 (0.003–0.006)<0.00010.150.004 (0.003–0.006)<0.00010.160.003 (0.001–0.005)0.0010.23
  • *Model 1: adjusted for age, sex, season, ethnicity.

  • †Model 2: adjusted as in model 1 plus supplements, total physical activity, parathyroid hormone.

  • ‡Model 3: adjusted as in model 2 plus BMI.

  • §R2 is the coefficient of determination for the model.

  • ‖Log transformations.