The Impact of Myo-Inositol on Glycemic Control and Oxidative Stress in Gestational Diabetes Mellitus

The Impact of Myo-Inositol Supplementation on Glycemic Control and Oxidative Stress in Women With Gestational Diabetes Mellitus: A Randomized, Open-Label Pilot Study

The purpose of this clinical study is to investigate the potential effects of myo-inositol supplementation on changes in glycemic control parameters, oxidative stress, inflammatory biomarkers, psychometric markers, and body composition in participants with gestational diabetes mellitus (GDM).

The study duration is 3 to 3.5 months, depending on the time of GDM diagnosis. Before the active phase begins, there is a 10-day observation period during which participants' blood glucose levels are monitored using a continuous glucose monitoring device. In the subsequent 12-14-week study phase, participants will receive a supplement based on random group assignment. They will be allocated either to an intervention group (myo-inositol + folic acid) or a control group (folic acid). Both supplements will be taken until delivery.

The intervention group supplement contains 4 g myo-inositol and 400 μg folic acid (BIOGENA GmbH, Salzburg) and is to be taken twice daily with water - three capsules per meal. The control group supplement contains only 400 μg folic acid (BIOGENA GmbH, Salzburg) and is also taken twice daily, one capsule per meal. As this is a pilot study, both participants and study personnel will be aware of group assignments.

Blood glucose measurements will be repeated mid-study (around the 33rd week of pregnancy) and at the end (37th week of pregnancy) using glucose sensors. To improve the evaluation of glucose measurements, participants will keep dietary logs during these periods.

Three study visits are planned, during which the following assessments will be conducted. To determine the primary outcome, "time in range (TIR)" (time spent within the target glucose range), three glucose sensor measurements will be performed. At each visit, blood samples will be taken to analyze glycemic control parameters (hemoglobin A1c (HbA1c), fasting glucose, fasting insulin, Homeostasis Model Assessment (HOMA-IR), insulin dosage), oxidative stress markers (total antioxidant capacity, malondialdehyde levels), and inflammatory markers (interleukin-6 (IL-6), C-reactive protein (CRP)). Anthropometric measurements (weight gain, blood pressure, pulse) and body composition (Bioelectrical Impedance Analysis) will also be performed.

Additionally, maternal and fetal birth outcomes will be recorded, including cesarean section rates, fetal gestational weight, preterm birth rates, and neonatal hypoglycemia occurrence. To assess participants' well-being and physical activity, questionnaires will be distributed at the beginning and end of the study.

Inclusion Criteria:

• GDM diagnosis
• at least one of the HAPO-Study criteria: 2h-oGTT → >153 mg/dl, 1h-oGGT → >180 mg/dl, fasting plasma glucose > 92 mg/dl
• age between 18-45
• single pregnancy

Exclusion Criteria:

• T2DM
• T1DM
• Maturity Onset Diabetes of the Young (MODY)
• Latent Autoimmune Diabetes in Adults (LADA)
• pre pregnancy BMI >35
• oral antidiabetic drugs
• pre-existing renal disease
• heart disease and other chronic medical disorders
• allergies to any ingredients contained in the dietary supplements