Serum homocysteine and vitamin B12 levels in women with gestational diabetes mellitus

Objectives: Gestational diabetes mellitus (GDM) is described as a glucose intolerance of variable severity which begun or was firstly recognized during gravidity. Two major metabolic disorders, insulin resistance and β-cell dysfunction, currently play major role in pathogenesis of GDM. Our intention was to investigate total serum homocysteine and vitamin B12 levels in pregnant women with GDM and non-diabetic gravid women. Material and methods: Serum homocysteine and vitamin B12 levels were prospectively measured in a total of 79 pregnant women, 60 of whom were diagnosed with GDM, and 19 of whom were healthy controls. Serum homocysteine levels were analyzed by ELISA. Vitamin B12 concentrations were determined by chemiluminescent immunoassay, and lipids were determined enzymatically. Results: GDM and control groups did not differ in terms of the serum homocysteine levels (median 7.24 vs 7.97 umol/L, respectively, p = 0.15). Nor did we find any association between serum homocysteine levels and BMI (r = 0.06, p = 0.55, respectively). There was no correlation between serum homocysteine and fasting serum glucose (r = 0.3, p = 0.8, respectively). There was no relationship between serum homocysteine concentrations and glycosylated hemoglobin (HgbA1c) levels (r = 0.06, p = 0.67, respectively). Serum vitamin B12 concentrations did not differ between the GDM and control groups (median 286 vs 262 pg/mL, respectively, p = 0.17). We found that levels of Vitamin B12 correlated inversely with fasting serum glucose concentrations (r = -0.44, p = 0.0009). Vitamin B12 concentrations increased along with LDL (r = 0.27, p = 0.043) and HDL (r = 0.38, p = 0.004) levels, however were inversely correlated with serum triglycerides (r = -0.34, p = 0.009). Conclusions: GDM patients with low Vitamin B12 values tend to have higher fasting serum glucose and altered lipid profiles (high triglycerides, low HDL and LDL). In women with GDM, serum homocysteine levels are not associated with HbA1c level, fasting glycemia, or BMI.