The effect of myo-inositol supplementation on the prevention of gestational diabetes in overweight pregnant women: a randomized, double-blind, controlled trial.

BACKGROUND: This study strove to investigate the hypothesis that a low dosage of myo-inositol supplementation might decrease the likelihood of gestational diabetes in overweight, pregnant women. METHODS: A randomized, double-blind, controlled trial was performed on 60 eligible overweight, pregnant women, at 12-14 weeks of gestation, at two Iranian obstetric clinics. The participants were divided into two groups based on blocked randomization. The myo-inositol group received 2000 mg plus 400 µg folic acid daily and the control group received 400 µg of folic acid daily from 14-24 gestational weeks. The occurrence of gestational diabetes was determined based on 75-g 2-hour oral glucose tolerance test (OGTT) at 24-28 gestational weeks, which was the primary outcome of the study. The secondary outcomes were: the evaluation of insulin therapy, insulin resistance and lipid profile, gestational weight gain, and fetal and maternal outcomes. RESULTS: The incidence of gestational diabetes in myo-inositol group was noticeably minimized compared to that in the control group (RR=0.29, 95% CI: 0.09-0.94, P=0.037). There were no differences between the two groups in terms of fasting blood sugar, fasting insulin, homeostasis model assessment-estimated insulin resistance (HOMA-IR), insulin therapy, and triglyceride. There was no report of severe adverse drug reactions. CONCLUSIONS: The absolute risk reduction and the number-needed-to-treat for gestational diabetes were 26.8% (95% CI: 5.6-48) and 3.7 (95% CI: 2.1-18.0), respectively. Hence, it can be concluded that approximately one out of every four overweight pregnant women receiving myo-inositol benefitted from its daily intake.