Effects of myo-inositol on glucose variability in women with gestational diabetes.

OBJECTIVE: Myo-inositol supplementation prevents gestational diabetes (GDM) in women at risk and reduces insulin resistance in women with GDM. No data are available about its effect on glucose variability. The aim of this study was to evaluate the effects of a supplementation of myo-inositol on glucose variability in women with GDM. PATIENTS AND METHODS: Myo-inositol effect on glucose variability was studied in a pilot case-control study involving 12 consecutive pregnant women (median age 34 years, 25.0% insulin-treated) with GDM. Six women received myo-inositol 2 g plus 200 mg folic acid twice a day, the others received only folic acid. Information on side effects was collected. A continuous glucose monitoring system was wore before and at the beginning of the supplementation. Mean amplitude of glucose excursion (MAGE), standard deviation (SD) and variability coefficient were the indexes of glucose variability. RESULTS: Myo-inositol lowered glucose levels in the first days after the treatment was started. However, pre-post supplementation overall mean glucose difference was similar between groups (-4.8 vs. 5.0 mg/dL for controls and treated, respectively; p = 0.79). Pre-post differences in SD (13.7 vs. 6.0; p < 0.001), MAGE (3.5 vs.-1.5; p < 0.001) and variability coefficient (0.14 vs. 0.02; p < 0.001) were improved in myo-inositol group. No side effects were recorded. CONCLUSIONS: Myo-inositol is effective in reducing glucose variability in women with GDM. It could be a useful strategy for treating GDM.

The effect of myoinositol supplementation on insulin resistance in patients with gestational diabetes.

AIM: To test the hypothesis that myoinositol supplementation will improve insulin sensitivity as measured by markers of insulin resistance such as homeostasis model assessment of insulin resistance and adiponectin in women with gestational diabetes. METHODS: The trial was carried out in diet-treated patients with gestational diabetes diagnosed in our department between April 2008 and September 2009. Subjects were randomly assigned to receive either myoinositol supplementation (4 g daily) plus folic acid (400 µg daily)-the study group-or folic acid only (400 µg daily)-the control group. Both groups received the same diet prescription. Homeostasis model assessment of insulin resistance and adiponectin were assayed while fasting at the time of the diagnostic oral glucose tolerance test and after 8 weeks of treatment. RESULTS: There were 69 evaluable patients, 24 in the study group and 45 in the control group. Fasting glucose and insulin, and consequently homeostasis model assessment of insulin resistance, decreased in both groups (50% in the study group vs. 29% in the control group), but the decline in the study group was significantly greater than that in the control group (P = 0.0001). Adiponectin increased in the myoinositol group while it decreased in the control group (P = 0.009). CONCLUSION: Myoinositol improves insulin resistance in patients with gestational diabetes.