The Relationship Between Vitamin D Deficiency and Insulin Resistance in Pregnant Women with Gestational Diabetes

Background: Diabetes Mellitus is one of the most common medical disorders in pregnancy. The possibility of vitamin D deficiency as a pathogenesis for impaired glucose tolerance tests show a probable role of vitamin D in insulin secretion and reduction of insulin resistance. This study was assigned to evaluate relation between serum vitamin D level and insulin resistance in Gestational Diabetes Mellitus (GDM). Methods: This cross sectional study was done throughout one year between 2015-2016 in GDM patients (age, 20-40 years). After history taking and physical examination, the laboratory tests including : Fasting Blood Sugar (FBS), Glucose Tolerance Test (GTT), calcium, phosphorous, parathormone, 25(OH) vitamin D, insulin, HbA1C, TG, LDL, HDL were performed for all patients. Insulin resistance was calculated according to HOMA-IR formula. Vitamin D level was compared between patients with and without insulin resistance. Results: This research was performed in 93 GDM patients with average age (30.3 ± 5.6). Thirty eight patients with insulin resistance and 55 patients without insulin resistance were detected. The prevalence of vitamin D deficiency was 91.4% in all patients. There was no significant difference in vitamin D levels between insulin resistant and non insulin resistant group (P-value=0.51). In all variable parameters, only FBS and triglyceride level in insulin resistant group were more than non insulin resistant group (P-value<0.05). Conclusion: Obtained results showed not significant relationship between vitamin D deficiency and insulin resistance in GDM patients.