Clinical significance of Vitamin-D and other bone turnover markers on bone mineral density in patients with gestational diabetes mellitus

Objectives: To perform a correlation analysis of serum 25-hydroxy Vitamin-D[25-OH-D], bone turnover markers (BTMs), and bone mineral density (BMD) in patients with gestational diabetes mellitus (GDM) during mid-and late pregnancy and state the significance of these factors for guiding clinical prevention and control of GDM. Methods: This study involved 100 pregnant women with singleton pregnancies who visited our obstetrics and gynecology department, Baoding First Central Hospital, during January 2019 and December 2020. All participants had received more than five prenatal checkups and were assigned to a GDM group and a normal group according to the presence of GDM during the mid-pregnancy period. Serum 25-OH-D, BMD, and bone turnover markers (BTMs) were measured to analyze the differences between the two groups and observe possible correlations among these factors. Results: According to the examination results, GDM occurred in 31 (31%) participants, and the rest 69 (69%) were free of GDM during mid-pregnancy. No significant differences were observed between the two groups in basic clinical data and the serum levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) (p>0.05), whereas the fasting blood glucose (FBG) level in the GDM group was significantly higher than in the normal group (p<0.05). The serum 25-OH-D and BMD levels in the GDM group were lower than in the normal group, whereas the bone alkaline phosphatase (BALP), osteocalcin (OC), procollagen type I propeptide (PINP), and beta-isomerized C-terminal telopeptide (beta-CTx) levels in the GDM group were significantly higher than in the normal group, with the differences showing statistical significance (p<0.05, respectively). The results of Pearson's correlation analysis revealed that serum 25-OH-D was positively correlated with BMD (r =0.183, P <0.05) and negatively correlated with such BTMs as BALP, OC, PINP, and beta-CTx (r =-0.255,-0.369,-0.204,-0.610; p<0.05). Conclusion: During mid and late pregnancy, GDM patients are prone to Vitamin-D deficiency, which has an adverse effect on bone turnover, BMD, and even the health of the mother and the development of the fetus. Therefore, routine screening for Vitamin-D deficiency is recommended throughout pregnancy.