Insulin Sensitivity and Insulin Secretion Estimated by Homeostatic Model Assessment (HOMA) in Gestational Diabetes Mellitus

Background: Progressive insulin resistance (IR) is an important pathophysiologic mechanism of gestational diabetes mellitus (GDM). Homeostatic model assessment (HOMA) is commonly used as a parameter of the severity of insulin resistance. Aims: To determine indices of insulin resistance (IR) and β-cell function in gestational diabetes mellitus (GDM). Methods: This cross sectional study was conducted from March 2017 to September 2018 at Department of Endocrinology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. The study was performed with 41 GDM and equal number of pregnant women with normal glucose tolerance (NGT) diagnosed on basis of WHO criterion-2013 during 24 - 40 weeks of gestation. Serum glucose was measured by glucose oxidase method and fasting serum insulin was measured by chemiluminescent immunoassay. Equations of homeostatic model assessment (HOMA) were used to calculate insulin indices like-insulin resistance (HOMA-IR), β-cell function (HOMA-B) and insulin sensitivity (HOMA-%S). Data were analyzed and compared by statistical tests. Results: A total of eighty-two (82) subjects [41 women with GDM (age: 28.29 ± 3.79 years, BMI: 27.16 ± 4.13 kg/m2) and 41 women with NGT (age: 26.22 ± 5.13 years, BMI: 25.27 ± 3.01 kg/m2)] were included in this study. It was observed that GDM women were significantly older (p = 0.041) and had significantly higher BMI (p = 0.020) than pregnant women with NGT. The GDM group had significantly higher IR as indicated by higher fasting insulin value [GDM vs. NGT;10.19 (7.71 - 13.34) vs. 6.88 (5.88 - 8.47) μIU/ml, median (IQR);p = 0.001] and HOMA-IR [GDM vs. NGT;2.31 (1.73 - 3.15) vs. 1.42 (1.15 - 1.76), median (IQR);p < 0.001], poor β-cell secretory capacity [GDM vs. NGT;HOMA-B: 112.63 (83.52 - 143.93) vs. 128.60 (108.77 - 157.58), median (IQR);p = 0.04] and low insulin sensitivity [GDM vs. NGT;HOMA-%S: 43.29 (31.77 - 57.98) vs. 70.42 (56.86 - 86.59), median (IQR);p < 0.001]. Conclusions: GDM is associated with both insulin resistance and inadequate insulin secretion.

Comparison of Serum Lipid Profile between Gestational Diabetes Mellitus and Pregnant Women with Normal Glucose Tolerance

Background: Aberrant lipid metabolism presumed to have important relationship with gestational diabetes mellitus (GDM), though previous studies revealed inconsistent results on this area. Objectives: To identify the difference of serum lipid profile between gestational diabetes mellitus (GDM) and pregnant woman with normal glucose tolerance (NGT). Methods: This cross sectional study was conducted from January 2017 to December 2017 at Department of Endocrinology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with 31 GDM and equal number of NGT pregnant women diagnosed on the basis of WHO criteria-2013, during 24 - 40 weeks of gestation. Glucose was measured by glucose oxidase method and fasting serum lipid profile [Total cholesterol (TC), High Density Lipoprotein-cholesterol (HDL-C) and Triglyceride (TG)] was measured by enzymatic-colorimetric method. Data were analyzed and compared by statistical tests. Results: Among total sixty-two (62) study subjects, 31 were GDM (age: 27.52 ± 4.8 years, body mass index (BMI): 27.17 ± 3.3 kg/m2) and 31 were pregnant women with NGT (age: 24.94 ± 4.2 years, BMI: 25.43 ± 6.5 kg/m2). Mean age of GDM group was significantly higher than that of NGT group (p = 0.028). Women with GDM showed relatively higher BMI than NGT women but that was not statistically significant (p = 0.194). Fasting lipid profiles between GDM and NGT (GDM vs. NGT;total cholesterol: 194.21 ± 42.18 vs. 208.52 ± 42.18 mg/dl, p = 0.187;HDL-C: 47.50 ± 16.17 vs. 47.18 ± 11.71 mg/dl, p = 0.928;LDL-C: 109.25 ± 28.80 vs. 119.30 ± 34.76 mg/dl, p = 0.220 and triglyceride 204.78 ± 58.50 vs. 202.34 ± 79.18 mg/dl, p = 0.891) were not significantly different. The variations in all lipid fraction values were not statistically significant among GDM women when analyzed between BMI groups holding BMI cut-off at 23 kg/m2. No significant differences of any values of lipid profile were found in GDM women according to various age categories (Age < 25 years vs. ≥25 years). Conclusions: Lipid profile does not differ between women with GDM and pregnant woman with NGT.