Elevated plasma homocysteine levels in gestational diabetes mellitus.

OBJECTIVE: This prospective study investigated the occurrence of hyperhomocysteinemia in a population of patients with gestational diabetes. The aim was to determine whether elevated plasma homocysteine is associated with gestational diabetes in Turkish women.

STUDY DESIGN: This prospective controlled study was conducted in the Department of Obstetrics and Gynecology of the Baskent University Faculty of Medicine between April 2002 and June 2003, and involved 304 Turkish women with uncomplicated pregnancies who were at 24-28 weeks gestation. The women in the study were assigned to one of three groups according to the results of the 50-g glucose screening and the oral glucose tolerance test (OGTT): group 1 comprised women who had normal glucose levels (< or = 135 mg/dL) after the 50-g challenge; group 2 comprised women with abnormal screening test results (> 135 mg/dL) but normal OGTT results; and group 3 comprised patients with gestational diabetes mellitus (GDM) according to the OGTT. Levels of fasting glucose, homocysteine, vitamin B(12) and folic acid, total cholesterol, high density lipoprotein (HDL) cholesterol, and triglycerides, low density lipoprotein (LDL) cholesterol and very low density lipoprotein (VLDL) cholesterol levels were measured in the three groups. Levels of insulin sensitivity were calculated using the homeostasis model assessment (HOMA) formula.

RESULTS: The mean level of homocysteine in group 1 was significantly lower than the levels in groups 2 and 3 (p < 0.001) The mean triglyceride and VLDL levels in group 3 were significantly higher than the corresponding levels in group 1 (p < 0.05 for both). There were no significant differences among the groups with respect to levels of total cholesterol, vitamin B(12), folic acid, creatinine, fasting glucose or insulin. The mean HOMA value in group 3 was significantly higher than that in group 1 (p < 0.05). Only the blood glucose level after the 50-g glucose screening [p = 0.000, 95% confidence interval (CI) 0.009-0.027] had a significant correlation with homocysteine levels.

CONCLUSION: In this prospective study of Turkish women, we found that patients with gestational diabetes and women with abnormal screening test results (> 135 mg/dL) but normal OGTT results have higher homocysteine levels than normal pregnant women. This increased level seems to be related to an abnormal 50-g test but not to insulin resistance. Further investigations are needed to follow up for these patients in the postpartum period and later in their life.