In part 5 of this Exclusive Interview, Dr. Mary Loeken talks with Diabetes in Control Publisher Steve Freed during the ADA meeting in San Diego, CA about finding ways to study the effects of diabetes drugs on pregnant women.
Mary Loeken, PhD is an Associate Professor of Medicine at Harvard Medical School and an Investigator at Joslin Diabetes Center.
Transcript of this video segment:
Steve: We don’t do tests in pregnant women to see if all these other drugs are beneficial from what we know. Yet Sulfonylurea, glyburide, is approved for pregnancy and metformin. We don’t do a study with any drugs in a pregnant woman, yet these two are approved and we found them to be beneficial.
Dr. Loeken: There is a history of how one goes about testing drugs in pregnancy. In many cases there are preclinical studies that are performed with animal models and you try to do toxicity studies to see if there are any adverse effects. When I was setting out to do our experiments with metformin, I would say that the way that some of the other experiments were performed wouldn’t necessarily allow us to see endpoints for particular stimulation of the enzyme we were looking at and effects on the gene expression that we know can occur in diabetes. We felt that we needed to repeat those experiments, and at a dose that was close to a high end of a dose that would be given to women. Once there are safety concerns that have been overcome, the studies that have been performed have sometimes been done…well, I’ll give you an example. Some of the early studies that were done with glyburide in 1990’s or so were done with placentas after delivery where you can perfuse them. That is you can hook them up to a pump where there is glyburide going in and you look at what can come out through the fetal side. Where some of the older sulfonylureas could get through the placenta to fetal circulation, glyburide did not at meaningful levels. That then allowed studies where you would do in a random control insulin-treated women versus glyburide-treated women and look at the outcomes of pregnancy. Now I know of some studies, one of the other speakers at the same session that I’m at, Janet Rowan, has looked at comparisons of metformin and insulin in gestational diabetic pregnancies and she has been following the offspring of those mothers to see if there is long-term benefit. There have been beneficial effects of both insulin and metformin treatment, but there haven’t been enough of follow-up studies to determine the long-term effects on the offspring, which is one of the things we still think about.