Inositol Stereoisomers to Treat Gestational Diabetes

The investigators aim to compare the effect of different inositol stereoisomers supplementation in lowering insulin resistance levels after 8 weeks of treatment in pregnant women with GDM and in preventing adverse obstetric outcomes.

The study population includes 80 women with GDM, randomly allocated to subgroup A (folic acid 400 mcg/day), subgroup B (myo-inositol 2000 mg twice a day), subgroup C (D-chiro-inositol 250 mg twice a day), and subgroup D (Myo-inositol plus D-chiro-inositol 550mg/13,8 mg twice a day).

Folic acid or inositol stereoisomers will be administered starting at the enrolling time (24-28 week gestation, after GDM diagnosis) till the delivery.

The homeostasis model assessment of insulin resistance (HOMA-IR) and the sensitivity index (QUICKI) will be checked at the moment of the diagnostic oral glucose tolerance test (24-28 weeks) and after 8 weeks of treatment. Obstetric outcomes, the rate of women needed insulin therapy and insulin dosage will be registered.

Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance that begins or is first recognized during pregnancy (1). It is characterized by an increase of physiological insulin resistance and it is associated with an increased risk of perinatal and maternal morbidity (2,3).

Inositol is a six-carbon polyol, normally present in a variety of foods, which has been classified as an insulin sensitizing agent. It exists as nine different isomers including myo-inositol (MI) and D-chiro-inositol (DCI) that are the most represented in human body. Myo-inositol and D-chiro-inositol glycans administration has been reported to exert beneficial effects at metabolic, hormonal and ovarian levels (4-5).

Recently has been demonstrated that Myo-inositol supplementation improves insulin resistance in patients with GDM (6), whereas there aren't data about the use of D-chiro-inositol or Myo-inositol plus D-chiro-inositol in women affected by GDM.

In this proposed study, the investigators aim to compare the effect of different inositol stereoisomers supplementation (Myo-inositol, D-chiro-inositol or Myo-inositol plus D-chiro-inositol ) in lowering insulin resistance levels after 8 weeks of treatment in pregnant women with GDM and in preventing adverse obstetric outcomes. All the available inositol formulations also contain folic acid (200 mcg).

The study population includes 80 women with GDM, randomly allocated to subgroup A (folic acid 400 mcg/day), subgroup B (myo-inositol 2000 mg twice a day), subgroup C (D-chiro-inositol 250 mg twice a day), and subgroup D (Myo-inositol plus D-chiro-inositol 550mg/13,8 mg twice a day).

Dietary control, folic acid or inositol stereoisomers will be administered starting at the enrolling time (24-28 week gestation, after GDM diagnosis) till the delivery.

The homeostasis model assessment of insulin resistance (HOMA-IR) and the sensitivity index (QUICKI) will be checked at the moment of the diagnostic oral glucose tolerance test (24-28 weeks) and after 8 weeks of treatment. Obstetric outcomes, the rate of women needed insulin therapy and insulin dosage will be registered.

Eligibility Criteria:
Inclusion Criteria:

* Gestational Diabetes diagnosed within 24-28 weeks gestation
* Caucasian pregnant women

Exclusion Criteria:

* Pre-pregnancy diabetes
* Non-singleton pregnancy