Kaiser Permanente study suggests many pregnant patients could avoid insulin injections
By Jan Greene
A study of 11,321 patients treated for gestational diabetes with insulin or the medication glyburide did not find a difference in cesarean section rates or outcomes for the patients’ infants, suggesting many people with gestational diabetes could forego insulin injections in favor of taking a pill.
The study, published March 31 in JAMA Network Open, found no greater likelihood with glyburide of babies being born with hypoglycemia or being admitted to the neonatal intensive care unit (NICU), which had been a concern raised in previous studies.
“We emulated a randomized clinical trial with real-world data, and took into account many factors that previous research on glyburide versus insulin has not,” said lead author Monique Hedderson, PhD, a research scientist with the Kaiser Permanente Division of Research. “It appears that glyburide is safe, compared to insulin, in terms of neonatal outcomes and cesarean delivery.”
The study looked at 11,321 patients treated between 2007 and 2017. Of these, 10,249 used glyburide to control their gestational diabetes and 1,072 used insulin. Co-author Romain Neugebauer, PhD, a research scientist with the Division of Research, led the application of sophisticated causal inference and machine learning analytic techniques that aim to emulate a randomized trial using real-life, observational data.
The study found no statistically significant difference between users of glyburide or insulin in risk for low blood glucose in infants, large-for-gestational-age infants, or shoulder dystocia, an injury that can take place in childbirth of a large baby. There was also no difference in cesarean section rates. Patients using glyburide had a lower risk of a baby with neonatal respiratory distress and a lower risk of neonatal intensive care unit admission for their child, the study found.
Glyburide is a sulfonylurea medication used to treat type 2 diabetes. Its use in pregnancy has gone in and out of favor as research was published with varying outcomes for infant health. Research initially found the medication did not transfer to the fetus during pregnancy, and a later study suggested it did. Additional studies linking glyburide with higher rates of hypoglycemia and NICU admission than with use of insulin prompted many physicians to forego the drug’s use.
These studies had limitations, Hedderson said, such as dosages of glyburide in the clinical trials not reflecting real-world use. In contrast, the new study involved a sophisticated analysis that took many factors into account, she added, using medical records of actual patients receiving each type of therapy over a period of time.
Patient preference for glyburide
Most patients prefer to use a pill than an injection and the majority are able to control their blood sugar levels using glyburide, said study co-author Anne Regenstein, MD, a maternal-fetal medicine specialist with The Permanente Medical Group. “Based on our clinical experience, we feel very comfortable offering glyburide to control gestational diabetes,” she said. “Most of our patients are able to achieve good glucose control with a low dose of glyburide and the outcomes for their babies are good. I was happy to see the results of this study confirm what we experience in our practice.”
She noted that the study results apply to an integrated system, such as Kaiser Permanente, that provides ongoing nurse supervision to pregnant patients who need to manage their blood sugar by adjusting medication or lifestyle factors over time. “You would need someone watching the patients’ glucose closely,” Regenstein said. “We’re very strict with that.”
She noted that one of the outcomes of concern — large-for-gestational-age babies, which can result from high blood sugar being shared with the fetus during pregnancy — has been declining as enrollment has increased in the perinatal care program run by Kaiser Permanente Northern California, suggesting the effectiveness of close monitoring of gestational diabetes patients.
Regenstein and Hedderson said that while the results are encouraging, before recommending changes to clinical practice, the findings should be confirmed with a large prospective randomized trial that incorporates adjustments to dosage of glyburide and compares it to metformin, another oral medication being used to treat gestational diabetes. Hedderson said future research could look at long-term outcomes for mothers and babies comparing the various approaches to glycemic control.
The study was funded by The Permanente Medical Group’s Delivery Science and Applied Research program.
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About the Kaiser Permanente Division of Research
The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit divisionofresearch.kaiserpermanente.org or follow us @KPDOR.