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.