Table 3

Multiple linear regression models showing adjusted estimates for vitamin D/PTH groups 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/PTH groups
Vitamin D sufficientVitamin D deficient/insufficient
PTH 1st/2nd tertile (25-OH-D ≥75 nmol/L and PTH ≤3.8 pmol/L)PTH 3rd tertile 
(25-OH-D ≥75 nmol/L and PTH >3.8 pmol/L)PTH 1st/2nd tertile (25-OH-D <75 nmol/L and PTH ≤3.8 pmol/L)PTH 3rd tertile 
(25-OH-D <75 nmol/L and PTH >3.8 pmol/L)
EstimatePEstimatePEstimatePEstimateP
Matsuda index
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, Matsuda index at 3 monthsRef.−0.1050.29−0.02890.58−0.1510.01
 Model 2: model 1 plus duration of breast-feedingRef.−0.1040.30−0.02800.59−0.1540.01
 Model 3: model 2 plus physical activity and seasonRef.−0.0890.38−0.01880.72−0.1560.01
ISSI-2
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, ISSI-2 at 3 monthsRef.0.0030.96−0.0690.09−0.1260.008
 Model 2: model 1 plus duration of breast-feedingRef.0.0030.96−0.0700.09−0.1260.008
 Model 3: model 2 plus physical activity and seasonRef.0.0030.96−0.0730.08−0.1280.008
Fasting glucose
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, fasting glucose at 3 monthsRef.0.00300.860.0150.100.0200.05
 Model 2: model 1 plus duration of breast-feedingRef.0.00310.850.0150.100.0200.05
 Model 3: model 2 plus physical activity and seasonRef.0.00340.840.0150.090.0230.03
2-h glucose
 Model 1: age, ethnicity, family history of T2DM, previous GDM, BMI, 2-h glucose at 3 monthsRef.−0.0260.580.0380.120.0910.002
 Model 2: model 1 plus duration of breast-feedingRef.−0.0260.580.0380.130.0910.002
 Model 3: model 2 plus physical activity and seasonRef.−0.0270.580.0350.170.0940.002
  • The reference group is vitamin D sufficient with PTH in 1st/2nd tertile at 3 months postpartum. Boldface type indicates P < 0.05. Outcome variables are log transformed.