Table 3.
Separate generalised linear models between 25-hydroxyvitamin D (25(OH)D) and each of the following dependent variables: fasting plasma glucose (FPG), HOMA-IR, fasting insulin, and C-peptide (regression coefficients and 95% confidence intervals). Associations according to vitamin D deficiency at inclusion (25(OH)D < 50 nmol/L) with vitamin D sufficiency (25(OH)D ≥ 50 nmol/L) as reference.
| Univariate analysis | Multiple analysis (model 1) | Multiple analysis (model 2) | Multiple analysis (model 3)a | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | B | (95% CI) | p | B | (95% CI) | p | B | (95% CI) | p | B | (95% CI) | p | |
| FPGa | 745 | 0.13 | (0.04, 0.21) | <0.01 | 0.13 | (0.04, 0.22) | <0.01 | 0.10 | (0.01, 0.20) | 0.04 | 0.017 | (−0.10, 0.13) | 0.77 |
| HOMA-IRb | 731 | 0.16 | (0.04, 0.28) | <0.01 | 0.19 | (0.07, 0.32) | <0.01 | 0.14 | (0.01, 0.27) | 0.03 | 0.045 | (−0.10, 0.20) | 0.54 |
| Insulinc (fasting) | 731 | 16 | (6.4, 25) | <0.01 | 15.2 | (5.6, 25) | <0.01 | 10 | (0.39, 20) | 0.04 | −0.13 | (−11, 11) | 0.98 |
| C-peptided (fasting) | 731 | 70 | (14, 125) | 0.01 | 84 | (26, 141) | <0.01 | 63 | (5.2, 122) | 0.03 | 21 | (−45, 87) | 0.54 |
Model 1: adjusted for age, parity, education, and season. Model 2: the same as model 1, with additional adjustment for the sum of skinfolds at visit 1 and change in skinfolds from visit 1 to visit 2. Model 3: the same as model 2, with additional adjustment for ethnicity/geographic origin. aFPG: n = 645, AIC (Akaike' information criterion) = 1182; bHOMA-IR: n = 635, AIC = 1482; cInsulin: n = 635, AIC = 6971; dC-peptide: n = 635, AIC = 9259.