The study hypothesis was that treatment with oral GABA, or a combination of GABA–GAD, would hinder the progression of new-onset type 1 diabetes. The double-blind trial was designed to run for 1 year (Contemp Clin Trials. 2019;82:93-100) and recruited 97 children with newly diagnosed type 1 diabetes, aged 4-18 years, who were randomized to the three study groups. They were evaluated at baseline and months 1, 5, 8, and 12.
The trial had several limitations, however, which might explain the findings. A key limitation was that the researchers used a low dose of GABA – 1 to 1.5 g/m2 a day, given as a twice-daily oral dose, as mandated by the Food and Drug Administration. “For the GABA dose and the response, we are at the threshold. I don’t believe we are overdosing these kids,” Dr. McCormick said, noting that this is the first study done with GABA in humans.
In fact, GABA has a short half-life of around 2.5-5 hours, so the dose may need to be much higher to show an effect and perhaps administered three times a day, he said.
Another limitation was compliance with the twice-daily medication, especially because 35% of the patients were teenagers, and that it was a young population, with about a third of the patients aged younger that 8 years.
GABA and GABA–GAD should still be studied further, Dr. McCormick concluded, but “additional studies with a higher dose of GABA [given] three times a day, and not twice, are warranted.” Such studies also need to have more participants in each group.
The University of Alabama at Birmingham sponsored the study. Collaborators included Diamyd, NOW Foods, Janssen, and the Juvenile Diabetes Research Foundation. Dr. McCormick did not have any disclosures.
SOURCE: McCormick KL et al. EASD 2019, Abstract S05.1.