Table 3. Comparison of mean HbA1c and fasting glucose according to 25(OH)D quartiles.
| 25(OH)D level | Model 1 | Model 2 | Model 3 | |
|---|---|---|---|---|
| Mean (95% CI) | Mean (95% CI) | Mean (95% CI) | ||
| Fasting glucose (mg/dL) | Quartile 1 | 145.1(140.2–150.0) | 144.4 (139.5–149.3) | 144.7 (139.7–149.7) |
| Quartile 2 | 144.4(139.7–149.2) | 144.8 (140.1–149.5) | 145.1 (140.4–149.8) | |
| Quartile 3 | 142.7(138.1–147.4) | 144.1 (139.5–148.7) | 143.9 (139.3–148.4) | |
| Quartile 4 | 142.7(137.8–147.7) | 143.6 (138.7–148.4) | 143.0 (138.1–147.9) | |
| p for trend | 0.468 | 0.787 | 0.608 | |
| p for between groups | 0.893 | 0.988 | 0.945 | |
| Hemoglobin A1c (%) | Quartile 1 | 7.48 (7.32–7.64)* | 7.45 (7.29–7.61) | 7.47 (7.30–7.63)* |
| Quartile 2 | 7.20 (7.04–7.36) | 7.24 (7.08–7.39) | 7.25 (7.09–7.40) | |
| Quartile 3 | 7.13 (6.98–7.29) | 7.18 (7.03–7.33) | 7.17 (7.02–7.32) | |
| Quartile 4 | 7.19 (7.03–7.36) | 7.20 (7.05–7.36) | 7.19 (7.02–7.35) | |
| p for trend | 0.018 | 0.043 | 0.021 | |
| p for between groups | 0.018 | 0.083 | 0.050 |
Model 1, Adjusted by month of blood collection, sex and age
Model 2, Adjusted by Model 1 plus BMI, smoking, physical activity, hypertension medications, diabetic duration, total cholesterol, triglyceride and HDL cholesterol
Model 3, Adjusted by Model 2 plus log-PTH
*p<0.005 compared with Quartile 3 with the Bonferroni adjustment for multiple comparison