Maternal vitamin D status in Type 1 diabetic pregnancy: Impact on neonatal vitamin D status and association with maternal glycaemic control.

OBJECTIVE: 1. To examine relationships between 25-hydroxy vitamin D (25OHD) in women with type 1 diabetes (T1DM) during pregnancy, post-delivery and in cord blood. 2. To investigate interactions between maternal body mass index (BMI) and foetal vitamin D status. 3. To examine relationships between maternal 25OHD and glycosylated haemoglobin (HbA1c). METHODOLOGY: An observational study of 52 pregnant controls without diabetes and 65 pregnant women with T1DM in a university teaching hospital. 25OHD was measured by liquid chromatography tandem mass spectrometry. RESULTS: Vitamin D deficiency (25OHD <25nmol/L) was apparent in control and T1DM women in all 3 trimesters. All cord blood 25OHD were <50nmol/L. Maternal 25OHD correlated positively with cord 25OHD at all 3 trimesters in the T1DM group (p=0.02; p<0.001; p<0.001). Cord 25OHD was significantly lower for T1D women classified as obese vs. normal weight at booking [normal weight BMI <25kg/m(2) vs. obese BMI〉30kg/m(2) (nmol/L±SD); 19.93±11.15 vs. 13.73±4.74, p=0.026]. In the T1DM group, HbA1c at booking was significantly negatively correlated with maternal 25OHD at all 3 trimesters (p=0.004; p=0.001; p=0.05). CONCLUSION: In T1DM pregnancy, low vitamin D levels persist throughout gestation and post-delivery. Cord blood vitamin D levels correlate with those of the mother, and are significantly lower in obese vs normal weight women. Maternal vitamin D levels exhibit a significant negative relationship with HbA1c, supporting a potential role for this vitamin in maintaining glycaemic control.

3-Epi-25 hydroxyvitamin D in pregnancy.

OBJECTIVE: The physiological importance of the C3 epimers of vitamin D (3-epi-25OHD2/3) is uncertain and there have been limited studies determining the levels of these epimers in human populations. The aims of the current study were (1) to determine 3-epi-25OHD2/3 levels throughout non-diabetic and T1DM pregnancy, (2) to examine the relationships between 25OHD and 3-epi-25OHD, (3) to assess the impact of maternal BMI on 3-epi-25OHD and examine associations with markers of glycaemic control. METHODOLOGY: An observational study of 52 pregnant controls without diabetes and 65 pregnant women with T1DM in a university teaching hospital. 25OHD and 3-epi-25OHD were measured by liquid chromatography tandem mass spectrometry. RESULTS: 3-Epi-25OHD was found in 90.2% of control (median 0.9nmol/L; range 0.1-5.9nmol/L), and in 94.5% of T1DM, women (median 1.4nmol/L; range 0.1-10.5nmol/L). In both control and T1DM groups, maternal and cord 3-epi-25OHD correlated significantly with 25OHD. Seasonal variation in maternal 3-epi-25OHD levels was evident in both groups; Summer levels were significantly higher than all other seasons in the control group (p<0.001) and significantly higher than Spring (p=0.003) and Winter (p<0.001) in the T1DM group. In T1DM women HbA1c was significantly negatively correlated with 3-epi-25OHD at trimesters 1 and 2 (p=0.049; p=0.001) and with cord 3-epi-25OHD (p=0.012). Maternal BMI >30kg/m(2) had a significant negative impact on 3-epi-25OHD. CONCLUSION: Maternal 3-epi-25OHD exhibits seasonal variation and, in common with cord 3-epi-25OHD, correlates with 25OHD throughout both non-diabetic and T1D pregnancy. In T1DM women 3-epi-25OHD is associated with a key marker of glycaemic control.

Cardiovascular and metabolic abnormalities in the offspring of diabetic pregnancy.

AIMS/HYPOTHESIS: Maternal fuel metabolism is known to exert long range effects on the later development of children of diabetic mothers. Recently cardiovascular disease in adult life has been linked retrospectively with foetal malnutrition. The aim of this study was to identify whether markers for fuel-related cardiovascular programming exist for the offspring of diabetic pregnancy. METHODS: Sixty-one children aged 5 to 11 years, of mothers with Type I (insulin-dependent) diabetes mellitus were compared with 57 randomly selected control children of non-diabetic mothers similar in age, sex and social class. Fasting blood was taken for plasma glucose, insulin, lipids, IGF-1, plasminogen activating inhibitor 1 (PAI-1) and the adhesion molecules ICAM-1, VCAM-1 and E-Selectin. RESULTS: Fasting glucose and insulin were similar in the two groups. Differences existed between the offspring of diabetic and non-diabetic pregnancies (mean +/- SD) for total cholesterol (4.45+/-0.56 vs 4.18+/-0.66, p=0.03 ), LDL cholesterol (2.73+/-0.49 vs 2.39+/-0.54, p=0.001), Cholesterol-to-HDL ratio (3.41+/-0.76 vs 3.09+/-0.73, p=0.03), IGF-1 (22.5+/-7.3 vs 19.3+/-8, p=0.04), PAI-1 (20.1+/-6.2 vs 14.9+/-7.3, p=0.000), VCAM-1 (1852+/-444 vs 1509+/-385, p=0.000) and E-Selectin (geometric mean; 83.1 vs 63.9, p=0.001). CONCLUSION/INTERPRETATION: These results indicate that important differences in cardiovascular risk factors exist between glucose-tolerant children of Type I diabetic and non-diabetic mothers, even in childhood. These data suggest that offspring of diabetic mothers might be at an increased risk for the development of vascular disease in later life.