ASSOCIATION OF VITAMIN D AND INSULIN RESISTANCE IN GESTATIONAL DIABETES
Objective: To determine the association of vitamin D deficiency with insulin resistance among women diagnosed with gestational diabetes.
Study Design: Cross sectional study.
Place and duration of study: This study was conducted from January 2021 to December 2021 at Combined Military Hospital (CMH) Lahore.
Methodology: Two hundred pregnant women in the age group 20-35 years with gestational diabetes diagnosed by using 75-gram oral glucose tolerance test were included. Fasting blood specimens for glucose, insulin and vitamin D were obtained and analyzed on Roche Cobas c501 and Cobas e411. Based on the vitamin D level, enrolled patients were classified as vitamin D sufficient and vitamin D deficient using vitamin D cut off 20 nmol/L. Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) was calculated for estimation of insulin resistance. Fasting glucose, fasting insulin and HOMA IR were compared between the two groups.
Results: In this study, 200 pregnant women were inducted. Median age was 28 years (IQR 24-31). Median fasting plasma glucose, Vitamin D levels and HOMA-IR of the study population were 5.3 mmol/L, 19.5 nmol/L and 2.7 respectively. Mann-Whitney U test showed a significant difference (p<0.001) of vitamin D levels among insulin resistant and non- resistant patients. A strong association (p<0.001) between insulin resistance and vitamin D deficiency was established by Chi-square test. Spearman correlation between insulin resistance and vitamin D levels showed negative correlation between insulin resistance and vitamin D levels (r = -0.89).
Conclusion: A strong association was found between vitamin D deficiency and gestational diabetes mellitus (GDM). The negative correlation (r=-0.89) indicated that severe the deficiency of vitamin D, more pronounced the insulin resistance among pregnant women having GDM.