Pregnant women with a family history of diabetes who received combination myo-inositol and D-Chiro-inositol at an early gestational age showed no significant difference in rates of gestational diabetes mellitus (GDM) compared with a control group, according to recent research published in Diabetes Care.
“[W]e recommend that companies that manufacture antenatal supplements should not add inositol to their products, as there is not enough known regarding its efficacy,” researchers from the Coombe Women & Infants University Hospital in Dublin, Ireland wrote.
The researchers analyzed the rates of GDM in 240 women with a history of diabetes at a single center between January 2014 and January 2016. Patients were randomly assigned to receive daily combination myo-inositol (1100 mg) and D-Chiro inositol (27.6 g) with folic acid (400 mg), or 400 mg of daily folic acid alone in the control group.
There was a 23.3% incidence of GDM in the combination inositol group (n=28) compared with an 18.3% incidence of GDM in the control (n=22) group (P =.34), with both groups showing a mean fasting glucose tolerance of 81 mg/dL.
“We found that the incidence of neonatal hypoglycemia was greater in the intervention arm compared with the control,” the researchers wrote. “However, for this to be a clinically significant finding, all neonates in the study would require blood glucose sampling, which did not occur.”
There was no significant difference in rates of GDM by body mass index (BMI) category, with overweight and obese patients showing a GDM rate of 35% compared with a rate of 24% in the control group (P =.17). Patients in the normal BMI group had a 10% incidence of GDM compared with a 13% incidence rate in the control group (P =.66).
“Within the intervention arm, there was a greater number of women with GDM, making it more likely that their babies would be tested,” the researchers wrote. “Therefore, we cannot conclude that the intervention resulted in more cases of hypoglycemia, but in future studies, all babies should have their blood glucose recorded.”
No significant difference in mean birth weight between the combination inositol group (3467±562.2 g) and the control (3323±519.6 g) group (P =.52) was noted. There were also no significant differences between the inositol group and control groups regarding macosomia in babies born >4.5 kg (3% vs 2%; P =.65), babies born with a birth weight below the 10th centile (6% vs 3%; P =.19), and the rate of Caesarean delivery (32% vs 35%; P =.58).
“Similar to views held in previous reports, larger studies with varying doses of inositol are required to evaluate clinical effectiveness of inositol during pregnancy,” the researchers concluded.
Farren M, Daly N, McKeating A, et al. The prevention of gestational diabetes mellitus with antenatal oral inositol supplementation: a randomized controlled trial [published online March 21, 2017]. Diabetes Care. doi:10.2337/dc16-2449