Associations of serum vitamin D concentrations with obstetric glucose metabolism in a subset of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study cohort
Diabetic Medicine, 08/02/2012
McLeod DSA et al. – An association between mid–gestational 25–hydroxy vitamin D and fasting glucose was confirmed in a largely normoglycaemic and vitamin D–replete pregnant population. The correlation between 25–hydroxy vitamin D and β–cell function suggests that vitamin D may influence glucose metabolism through this mechanism. Intervention studies are required to determine causality and the role of vitamin D replacement in deficient individuals.Methods
- Cross–sectional assessment of 25–hydroxy vitamin D concentrations in 399 Hyperglycemia and Adverse Pregnancy Outcome ancillary study participants, treated at an obstetric teaching hospital in Brisbane, Australia.
- All patients underwent a blinded 75–g oral glucose tolerance test at 24–32 (target 28) weeks' gestation.
- The mean (± standard deviation) fasting plasma glucose was 4.5 ± 0.4 mmol/l.
- Mean (± standard deviation) serum 25–hydroxy vitamin D was 132.5 ± 44.0 nmol/l.
- A difference of one standard deviation in maternal 25–hydroxy vitamin D was inversely related to fasting glucose (fasting glucose lower by 0.047 mmol/l, P = 0.012) when assessed with multiple linear regression after adjusting for confounders.
- Maternal 25–hydroxy vitamin D correlated with β–cell function as estimated by the log–transformed homeostasis model assessment–β–cell function equation (r = 0.131, P = 0.009), but not with the homeostasis model assessment of insulin resistance.