O’Brien et al. Nutrition & Metabolism (2017) 14:50 DOI 10.1186/s12986-017-0203-5
RESEARCH
Open Access
Season and vitamin D status are independently associated with glucose homeostasis in pregnancy Eileen C. O’Brien1, Elizabeth J. O’Sullivan1, Mark T. Kilbane2, Aisling A. Geraghty1, Malachi J. McKenna1,3,4 and Fionnuala M. McAuliffe1*
Abstract Background: Vitamin D status and season are intrinsically linked, and both have been proposed to be associated with glucose homeostasis in pregnancy, with conflicting results. We aimed to determine if exposure to winter and low maternal 25 hydroxyvitamin D (25OHD) in early pregnancy were associated with maternal glucose metabolism. Methods: This is a secondary data analysis of 334 pregnant women enrolled in the ROLO study, Dublin. Serum 25OHD, fasting glucose, insulin and insulin resistance (HOMA-IR) were measured in early (12 weeks’ gestation) and late pregnancy (28 weeks’ gestation). Season of first antenatal visit was categorised as extended winter (November– April) or extended summer (May–October). Multiple linear regression models, adjusted for confounders, were used for analysis. Results: Those who attended their first antenatal visit in extended winter had lower 25OHD compared to extended summer (32.9 nmol/L vs. 44.1 nmol/L, P < 0.001). Compared to those who attended their first antenatal visit during extended summer, extended winter was associated with increased HOMA-IR in early-pregnancy (46.7%) and late pregnancy (53.7%), independent of 25OHD
RESEARCH
Open Access
Season and vitamin D status are independently associated with glucose homeostasis in pregnancy Eileen C. O’Brien1, Elizabeth J. O’Sullivan1, Mark T. Kilbane2, Aisling A. Geraghty1, Malachi J. McKenna1,3,4 and Fionnuala M. McAuliffe1*
Abstract Background: Vitamin D status and season are intrinsically linked, and both have been proposed to be associated with glucose homeostasis in pregnancy, with conflicting results. We aimed to determine if exposure to winter and low maternal 25 hydroxyvitamin D (25OHD) in early pregnancy were associated with maternal glucose metabolism. Methods: This is a secondary data analysis of 334 pregnant women enrolled in the ROLO study, Dublin. Serum 25OHD, fasting glucose, insulin and insulin resistance (HOMA-IR) were measured in early (12 weeks’ gestation) and late pregnancy (28 weeks’ gestation). Season of first antenatal visit was categorised as extended winter (November– April) or extended summer (May–October). Multiple linear regression models, adjusted for confounders, were used for analysis. Results: Those who attended their first antenatal visit in extended winter had lower 25OHD compared to extended summer (32.9 nmol/L vs. 44.1 nmol/L, P < 0.001). Compared to those who attended their first antenatal visit during extended summer, extended winter was associated with increased HOMA-IR in early-pregnancy (46.7%) and late pregnancy (53.7%), independent of 25OHD
