Endocrine Abstracts

Background and aim: Gestational Diabetes Mellitus (GDM) is the commonest medical pregnancy complication. Nutritional interventions come to the fore as one of the few levers for managing GDM, as many medications are either harmful to the growing fetus, or their toxicity is uncertain. The aim of this study was to assess the potential clinical features and nutritional risk factors of insulin treatment during GDM.

Methods: This was a prospective study including 150 patients with GDM. Patients who failed to achieve glycemic targets, defined according to the American Diabetes Association guidelines 2021, were treated with insulin. Clinical caracteristics and dietary intake were compared between the two groups. Dietary intake data were collected by trained nutritionists using a 24-hour recall method.

Results: Among the 150 patients with GDM, insulin use, along with lifestyle interventions, was necessary in 20.3% of patients. Univariate analysis showed that insulin use was significantly associated with a family history of type 2 diabetes in a first degree relative (P=0.016), history of GDM (P=0.02), pregestational Body Mass Index superior to 25 kg/m² (P=0.005) and presence of four risk factors of GDM (P=0.005). Insulin therapy group had higher protein intake than nutritional therapy group (100.86 ±38.8 g/d vs 80.28 ±36.97 g/d,P=0.025) and lower vitamin B12 levels (3.93 ±2.84 μg/d vs 2.59±1.78 μg/d,P=0.01). Energy consumption, carbohydrate intake, fat intake and fiber intake did not statistically differ between the two groups (P=0.7,P=0.09, P=0.89, P=0.6 respectively). The calcium, iron, zinc, magnesium, vitamin B1, B2, B3, B5, B6 and folic acid intakes did not statistically differ between the two groups. Multivariate analysis showed that vitamin B12 level was an independant factor for insulin requirement during GDM (OR 5.52, 95% CI 1.33-22.83, P=0.018). The cut-off value of vitamin B12 level, determined by ROC curves analysis, was 2.28 μg/d (sensitivity of 80% and specificity of 52%,P=0.01).

Conclsion: The association between vitamin B12 levels during pregnancy and the risk of GDM remains unclear with conflicting data. To our knowledge, this is the first study to elucidate the association between vitamin B12 levels and insulin requirement during GDM. More studies are needed to further strengthen this finding and to clarify possible pathogenetic mechanisms.