Abstract
Background:
Vitamin D deficiency is thought to impair insulin action and glucose metabolism; however previous studies have not examined ethnic differences or the influence of calcium and parathyroid hormone. We investigated this in a cohort of predominantly White European and South Asian women during pregnancy.
Methods:
In this cross-sectional study from an urban population in northern England (53.8°N) 1467 women were recruited when undergoing glucose tolerance testing (75g OGTT) at 26 weeks gestation.
Results:
Gestational diabetes (GDM) was diagnosed in 137 women (9.3%). Median 25(OH)D concentration for the study population was 9.3ng/mL (interquartile range (IQR) 5.2, 16.9) and was higher in European (15.2ng/mL (10.7, 23.5)) than in South Asian women (5.9 ng/mL (3.9, 9.4), p<0.001). After appropriate adjustment for confounders, 25(OH)D showed a weak inverse association with fasting plasma glucose (FPG; mean difference 1.0% per 1SD; ratio of geometric means (RGM) 0.99, 95% confidence interval (CI) 0.98, 1.00), and PTH was weakly associated with FPG (RGM 1.01, 95% CI 1.00, 1.02) but neither was associated with fasting insulin, post-challenge glucose or GDM. Serum calcium (albumin-adjusted) was strongly associated with fasting insulin (RGM 1.06; 95% CI 1.03, 1.08), post-challenge glucose (RGM 1.03, 95% CI 1.01, 1.04) and GDM (odds ratio 1.33, 95% CI 1.06, 1.66), but not with FPG. Associations were similar in European and South Asian women.
Conclusions:
These findings do not indicate any important association between vitamin D status and glucose tolerance in pregnancy. Relationships between circulating calcium and glucose metabolism warrant further investigation.
Vitamin D deficiency is thought to impair insulin action and glucose metabolism; however previous studies have not examined ethnic differences or the influence of calcium and parathyroid hormone. We investigated this in a cohort of predominantly White European and South Asian women during pregnancy.
Methods:
In this cross-sectional study from an urban population in northern England (53.8°N) 1467 women were recruited when undergoing glucose tolerance testing (75g OGTT) at 26 weeks gestation.
Results:
Gestational diabetes (GDM) was diagnosed in 137 women (9.3%). Median 25(OH)D concentration for the study population was 9.3ng/mL (interquartile range (IQR) 5.2, 16.9) and was higher in European (15.2ng/mL (10.7, 23.5)) than in South Asian women (5.9 ng/mL (3.9, 9.4), p<0.001). After appropriate adjustment for confounders, 25(OH)D showed a weak inverse association with fasting plasma glucose (FPG; mean difference 1.0% per 1SD; ratio of geometric means (RGM) 0.99, 95% confidence interval (CI) 0.98, 1.00), and PTH was weakly associated with FPG (RGM 1.01, 95% CI 1.00, 1.02) but neither was associated with fasting insulin, post-challenge glucose or GDM. Serum calcium (albumin-adjusted) was strongly associated with fasting insulin (RGM 1.06; 95% CI 1.03, 1.08), post-challenge glucose (RGM 1.03, 95% CI 1.01, 1.04) and GDM (odds ratio 1.33, 95% CI 1.06, 1.66), but not with FPG. Associations were similar in European and South Asian women.
Conclusions:
These findings do not indicate any important association between vitamin D status and glucose tolerance in pregnancy. Relationships between circulating calcium and glucose metabolism warrant further investigation.
| Original language | English |
|---|---|
| Pages (from-to) | 938-946 |
| Journal | The Journal of Clinical Endocrinology & Metabolism (JCEM) |
| Volume | 99 |
| Issue number | 3 |
| Early online date | 1 Jan 2014 |
| DOIs | |
| Publication status | Published - 2014 |