Impact of first trimester fasting glycemic levels on expression of proteoglycans in pregnancy

Aim: The aim of this study was to assess the influence of glucose metabolism on the expression of glycosaminoglycans (GAGs) and proteoglycans (PGs) in pregnant women.

Material and methods: Seventy-six women in the first trimester of pregnancy (10-13 weeks) attending the Gynecologic and Obstetric Clinic, University of Sassari, were enrolled and gave early morning urine samples. Groups I, II and III included women with serum glucose values of 65-89 mg/dL, 90-99 mg/dL and 100-125 mg/dL, respectively. Urine GAGs/PGs distribution was determined by electrophoresis on cellulose acetate strips. Urinary N-Acetyl-β-glucosaminidase was estimated kinetically.

Results: Analysis of urinary GAGs/PGs electrophoretic profiles showed a significant increase in heparan sulfate (HS) excretion (P = 0.017) as well as a reduced chondroitin sulfate (CS) excretion (P = 0.048) in the group II pregnant women compared with the group I, and higher values of the HS/CS ratio in groups II and III compared to group I. Furthermore, we observed a positive correlation among fasting blood glucose levels and the relative content of HS, the HS/CS and urinary trypsin inhibitor/CS ratios, and the N-Acetyl-β-glucosaminidase levels.

Conclusions: The assessment of risk factors for gestational diabetes mellitus should also take into account fasting blood glucose values of 90-99 mg/dL, as the findings of our study indicated an alteration in the metabolism of GAGs during the early stages of pregnancy.