Table 2

Association between exposures and T1D

OR (95% CI)aOR (95% CI)*P
DBP, per 1 μmol/L increase
 Predicted maternal DBP0.74 (0.39–1.22)0.49 (0.18–1.02)NS
 Midpregnancy1.03 (0.91–1.16)0.96 (0.79–1.16)0.65
 Cord blood0.98 (0.81–1.20)0.87 (0.67–1.14)0.32
 Postpartum0.86 (0.74–0.98)0.80 (0.67–0.95)0.01
25(OH)D-to-DBP ratio
 Midpregnancy1.00 (0.96–1.04)1.04 (0.98–1.09)0.17
 Cord blood0.99 (0.97–1.01)1.00 (0.97–1.04)0.81
 Postpartum1.01 (0.98–1.04)1.05 (1.00–1.10)0.049
25(OH)D, per 10 nmol/L increase, stratified by VDR rs11568820§
 Cord blood, AA/AG1.18 (1.00–1.40)1.17 (0.95–1.44)0.15
 Cord blood, GG0.87 (0.77–0.98)0.85 (0.72–1.00)0.047
  • P value shown for adjusted analysis. aOR, adjusted OR.

  • *Adjusted for child’s HLA genotype and sex and maternal ethnicity, age, prepregnancy BMI, cesarean section, and smoking.

  • †Using maternal (midpregnancy and postpartum) samples in a mixed model to predict maternal DBP values at gestational week 36. Owing to the reduction of the sampling variation in prediction of maternal DBP, the predicted values have a lower SD of 0.35 (while, e.g., DBP in the postpartum samples has an SD of 1.52). This results in a greater observed estimate, as an increase per unit is roughly equivalent to 3 SD in this analysis. We used bootstrapping (10,000 replications) to obtain unbiased CIs and present bias-corrected CIs.

  • ‡As these results arise from bootstrapping estimations, a P value is not provided.

  • §There was a statistically significant interaction (Pinteraction = 0.01) between rs11568820 and 25(OH)D (Supplementary Table 3).