Effect of inositol stereoisomers at different dosages in gestational diabetes: an open-label, parallel, randomized controlled trial

Gestational diabetes mellitus (GDM) is the most common metabolic disorder of pregnancy. The aim of the study is to compare the effect of different dosages of inositol stereoisomers supplementation on insulin resistance levels and several maternal-fetal outcomes in GDM women. Participants were randomly allocated to receive daily: 400 mcg folic acid (control treatment), 4000 mg myo-inositol plus 400 mcg folic acid (MI treatment), 500 mg d-chiro-inositol plus 400 mcg folic acid (DCI treatment) or 1100/27.6 mg myo/d-chiro-inositol plus 400 mcg folic acid (MI plus DCI treatment). The homeostasis model assessment of insulin resistance (HOMA-IR) was measured at the diagnosis of GDM and after 8 weeks of treatment. Secondary outcomes, obstetric outcomes and any maternal or fetal complication at delivery were also collected. Eighty GDM women were assigned to one of the four arms of study (20 per arm). A significant delta decrease in HOMA-IR index was found in subjects of MI group without insulin therapy compared to control group (p < 0.001). A lower variation in average weight gain (at delivery vs pre-pregnancy and OGTT period) was detected in MI group vs control group (p = 0.001 and p = 0.019, respectively). Moreover, women exposed to MI and MI plus DCI required a significantly lower necessity of an intensified insulin treatment. Women of the control group had newborns with higher birth weight compared with women treated with inositol (p = 0.032). Our study provides interesting but preliminary results about the potential role of inositol stereoisomers supplementation in the treatment of GDM on insulin resistance levels and several maternal-fetal outcomes. Further studies are required to examine the optimal and effective dosages of different inositol supplements. NCT02097069, ClinicalTrial.gov.