Over-the-counter nutritional supplement may help avert gestational diabetes

Myo-inositol, a nutritional supplement that is present in fruits and fibre-rich foods, shows promise in the prevention of gestational diabetes, as reported in a study.

The study randomly assigned 198 multiethnic pregnant women between 12 and 15 weeks of gestation to the intervention or the control arm. The intervention arm received myo-inositol 2 g supplement with 200 µg folic acid, to be taken twice a day in a powder form mixed in water, approximately 1 hour before or after a meal. The placebo arm was given an identical looking and tasting powder of xylitol filler with 200-µg folic acid.

Over one-third of the population were obese (37 percent in the intervention arm, 36 percent control), and around half were nulliparous (51 percent in the intervention arm, 40 percent in the control arm). More than half (60 percent) had a first-degree relative with type 2 diabetes, and one in 10 (8 percent intervention; 11 percent control) had a history of previous gestational diabetes.

The primary outcome measures were rates of recruitment, randomization, adherence, and follow-up. These were ascertained in 90 percent of the population (178 out of 198) by delivery.

Mean adherence to the interventions was 52 percent at 28 weeks’ and 34 percent at 36 weeks’ gestation. Compared with the placebo arm, the myo-inositol arm had lower homoeostatic model assessment-insulin resistance (HOMA-IR; mean difference, −0.6, 95 percent confidence interval [CI], −1.2 to 0.0) and serum insulin levels (mean difference, −2.69, 95 percent CI, −5.26 to −0.18).

Both the participants and healthcare professionals found the study procedures to be acceptable. Of note, women who perceived themselves at high risk of gestational diabetes were more inclined to participate and adhere to the intervention. Key barriers to adherence included the powder form of myo-inositol and placebo as well as nausea in pregnancy.

The findings suggest that a future trial on myo-inositol to prevent gestational diabetes is feasible, although the intervention will need to be delivered in a nonpowder form to improve adherence.