Table 2

Multiple linear regression models showing adjusted estimates for vitamin D status at 3 months postpartum and PTH tertile at 3 months postpartum in predicting glucose/metabolic outcomes at 12 months postpartum adjusted for the indicated covariates in each model

Outcomes at 12 monthsVitamin D status at 3 monthsTertiles of PTH at 3 months
Deficient 
(25-OH-D <50 nmol/L)Insufficient
(50 nmol/L ≤ 25-OH-D <75 nmol/L)2nd
(2.6 pmol/L < PTH ≤ 3.8 pmol/L)3rd
(PTH >3.8 pmol/L)
EstimatePEstimatePEstimatePEstimateP
Matsuda index
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, Matsuda at 3 months−0.1050.06−0.0140.77−0.0270.59−0.1350.01
 Model 2: model 1 plus duration of breast-feeding−0.1070.06−0.0130.79−0.0320.52−0.1410.008
 Model 3: model 2 plus physical activity and season−0.0990.08−0.0130.79−0.0320.53−0.1430.008
ISSI-2
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, ISSI-2 at 3 months−0.0510.23−0.1160.004−0.0410.30−0.0770.07
 Model 2: model 1 plus duration of breast-feeding−0.0510.23−0.1160.004−0.0400.31−0.0760.07
 Model 3: model 2 plus physical activity and season−0.0620.16−0.1110.006−0.0420.30−0.0750.08
Fasting glucose
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, fasting glucose at 3 months0.0230.020.0110.200.0030.690.0090.34
 Model 2: model 1 and duration of breast-feeding0.0230.020.0110.200.0040.660.0090.33
 Model 3: model 2 plus physical activity and season0.0260.0080.0110.200.0040.670.0100.25
2-h glucose
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, 2-h glucose at 3 months0.0690.0090.0540.030.0320.180.0610.02
 Model 2: model 1 plus duration of breast-feeding0.0690.0090.0530.030.0340.160.0630.01
 Model 3: model 2 plus physical activity and season0.0700.010.0510.040.0420.090.0710.007
  • For the vitamin D groups, the reference group is vitamin D sufficiency at 3 months postpartum. For PTH tertiles, the reference group is the 1st tertile at 3 months postpartum. Boldface type indicates P < 0.05. Outcome variables are log transformed.