TABLE 2

Multiple linear regression analysis of associations of baseline 25(OH)D (nmol/L) with measures of insulin sensitivity/resistance and β-cell function and AUCglucose at the 3-year follow-up

Outcome per unit increase in baseline 25(OH)DModel 1Model 2Model 3
β (95% CI)PR2β (95% CI)PR2β (95% CI)PR2
IS-OGTT*0.002 (−0.0004 to 0.004)0.120.490.002 (−0.0006 to 0.004)0.160.500.001 (−0.001 to 0.003)0.340.62
HOMA-IR*−0.003 (−0.005 to −0.0006)0.0140.36−0.003 (−0.005 to −0.0003)0.0280.37−0.001 (−0.003 to 0.001)0.320.53
IGI/IR*0.007 (0.003–0.010)0.00030.180.007 (0.003–0.010)0.00060.180.005 (0.0009–0.008)0.0150.29
ISSI-2*0.002 (0.0004–0.003)0.0140.360.002 (0.0005–0.004)0.0090.360.002 (0.0003–0.003)0.0230.44
AUCglucose*−0.001 (−0.002 to −0.0005)0.00100.40−0.001 (−0.002 to −0.0004)0.00220.40−0.001 (−0.002 to −0.0003)0.0070.45
  • Model 1: adjusted for age, sex, ethnicity, season of 25(OH)D measurement, and baseline outcome variable. Model 2: adjusted as in model 1 plus baseline physical activity, change in physical activity, baseline vitamin D supplement use, and change in vitamin D supplement use. Model 3: adjusted as in model 2 plus baseline BMI and change in BMI.

  • *Log transformations.