Endocrine Abstracts

Introduction: Gestational diabetes mellitus (GDM) is the most common metabolic disturbance during pregnancy. The prevalence of GDM is rising and correlates with the increase in maternal obesity over recent decades. The aim of our study was to assess the association between maternal insulin resistance with pregnacy outcomes and maternal characteristics among tunisians women with GDM.

Methods: A prospective longitudinal study carried out during the year 2020 at the research unit of GDM of Department C at the National Institute of nutrition of Tunis. The study was conducted among 135 women diagnosed with GDM with 75 g oral glucose tolerance test (OGTT 75) between 24–28 weeks. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR). Patients are followed during pregnancy and until post partum. Statistical analyses were performed using SPSS 20.

Results: The mean age was 32.3 ± 5.3 years. The mean pre-gestational BMI was 28.31 ± 4.9 kg/m^². Two thirds of the patients (72.4%) were overweight and 29.9% were obese. The means of fasting blood glucose and the number of abnormal glycemia values at time of OGTT 75 were respectively 0.96 ± 0.11 g/l and 1.45 ± 0.63. The means of fasting blood glucose, HbA1c and total cholesterol were 4.85 ± 0.69 mmol/l, 5.32 ±0.43% and 5.87 1.25 mmol/l. One third of patients (36.3%) were diagnosed before 24 gestational weeks. The mean HOMA-IR was 3.18 ± 1.7 and 55.3% of women had insulin resistance. Macrosomia and pregnancy induced-hypertension were noted in 15.8% and 3.8% of cases. The univariable analysis showed an association between the HOMA-IR and the pre-gestational BMI, fasting blood glucose and the number of abnormal glycemia values at the time of OGTT 75, levels of HbA1c, fasting glucose value, C-peptide and total cholesterol and also with an earlier diagnosis of GDM before 24 gestational weeks (respectively P < 0.01, P < 0.01, P = 0.004, P < 0.01, P < 0.01, P < 0.01, P = 0.049 and P = 0.019). however, there was no association between the HOMA-IR and pregnacy outcomes.

Conclusion: Our study showed that The HOMA-IR was associated with advanced maternal age, higher pre-gestational BMI, higher fasting blood glucose, HbA1c, and C-peptide levels. Women followed for GDM with higher HOMA-IR remain a high risk population and more researchs are necessary to improve outcomes in this group.