ABSTRACT
Objective To explore the relationship between different statuses of vitamin D and parathyroid hormone (PTH) during pregnancy with glucose metabolism and the risk of gestational diabetes mellitus (GDM). Methods A total of 4138 pregnant women who had antenatal care in 3 hospitals of Hefei from March 2015 to December 2017 were recruited during 21-24 weeks. Baseline questionnaires were performed and serum 25-hydroxyvitamin D [25(OH) D] and PTH levels were measured in fasting venous blood. Glucose tolerance tests were performed during 24 to 28 weeks. Multivariate linear regression model and multivariate logistic regression model were applied to analyze the differences of glucose metabolism index and GDM risk among pregnant women at different statusesof25(OH)DandPTH.Results Theaveragelevelof25(OH)Dinthesecondtrimesterwas(39.8±16.6) nmol/L, with the median PTH 10.7 (6.9, 16.7) ng/L and the detection rate of GDM 20.4％. Covariance analysis showed no statistically significant association of vitamin D and PTH levels with glucose metabolism indexes. Pregnant women with high PTH and vitamin D deficiency had higher 1h postprandial plasma glucose ( 1hPG) , the area under the glucose curve ( AUCglu ) levels, and GDM risk compared with pregnant women with middle/lower PTH and vitamin D deficiency ( control group, all P<0.05) , and higher PTH accompanied with vitamin D non-deficiency ( Group 2, all P<0.05) . However, significant changes in glucose metabolism indicators and GDM risk were not observed in low-level PTH-pregnant women with vitamin D deficiency ( group 1) and group 2 pregnant women compared with control group. Conclusion There is an interaction between vitamin D/PTH levels and glucose metabolism during pregnancy. Vitamin D deficiency with elevated PTH level is associated with abnormal glucose metabolism.