GLP-1 Drugs Don't Cause Dangerous Blood Sugar Drops in Developing Rat Pups | Research

The takeaway

Incretin-based therapies (GLP-1 agonist and DPP-4 inhibitor) did not cause hypoglycemia in newborn rats, suggesting they could safely treat high blood sugar in premature babies.

63% incretin effect in newborn rats
The gut-hormone insulin-boosting system is already fully functional in developing rat pups, and GLP-1 drugs caused zero hypoglycemic episodes

What the researchers found

The incretin effect — where gut hormones boost insulin secretion after eating — is fully functional in developing 2-week-old rat pups, with an incretin effect of 63% (meaning 63% of the insulin response to oral glucose came from gut-stimulated incretin hormones rather than glucose alone).

Critically, when the researchers gave standard therapeutic doses of a DPP-4 inhibitor (linagliptin) or a GLP-1 receptor agonist (liraglutide) to the pups, neither drug caused dangerous drops in blood sugar. This is significant because hypoglycemia is the major concern when treating high blood sugar in preterm infants.

The findings suggest that incretin-based therapies could be a safer approach to treating hyperglycemia in extremely premature babies compared to insulin, which carries substantial hypoglycemia risk.

Why it matters

Extremely premature babies frequently develop dangerously high blood sugar, but treating them with insulin is risky because it can cause hypoglycemia — which can damage the developing brain. If incretin-based drugs (GLP-1 agonists or DPP-4 inhibitors) can lower blood sugar without causing hypoglycemia in developing organisms, they could offer a much safer treatment option for this vulnerable population.

The numbers in context

Incretin effect: 63% · 2-week-old Wistar rat pups · Linagliptin and liraglutide tested · 0 hypoglycemic events · OGTT vs IPGTT comparison

How the study worked

Researchers performed oral glucose tolerance tests (OGTT) and intraperitoneal glucose tolerance tests (IPGTT) in 2-week-old Wistar rat pups, comparing serum glucose, insulin, and incretin hormone levels between the two routes. They then administered standard therapeutic doses of linagliptin (DPP-4 inhibitor) and liraglutide (GLP-1 agonist) to developing pups and monitored for hypoglycemia.

Who was studied

2-week-old Wistar rat pups (developing neonatal animal model)

What this study cannot tell us

This is an animal study in rats — results may not directly translate to human preterm infants, whose metabolic systems differ from rodents. The 2-week-old rat pup is an imperfect model for human prematurity. No hyperglycemic model was tested — the drugs were given to normal pups, not to pups with the kind of hyperglycemia seen in preterm infants. Clinical trials in neonates would be needed before any treatment recommendation.

How to read the evidence

This is a preclinical animal study in developing rats. While the experimental design is sound and the findings are consistent, the results need to be validated in human neonates before clinical application, placing evidence at a low-to-moderate level.

When this study was published

Published in 2026, this is a very recent study exploring a novel potential application for incretin-based therapies in neonatal medicine — a field where these drugs have not previously been studied.

The bigger picture

Neonatal hyperglycemia management is a significant unmet need in neonatal intensive care. GLP-1-based therapies are already transforming adult diabetes and obesity treatment. If their safety profile extends to the developing neonatal system, it could open an entirely new clinical application for these peptide drugs — protecting the most vulnerable patients from both hyperglycemia and the risks of insulin treatment.

Questions still open

Will incretin-based therapies lower elevated blood sugar in a neonatal hyperglycemia model, not just avoid hypoglycemia in normal pups?
How does the developing human neonatal incretin system compare to the 2-week-old rat model?
Could incretin-based therapy reduce neurodevelopmental harm from neonatal hyperglycemia without the hypoglycemia risk of insulin?

Common questions

Why is high blood sugar dangerous for premature babies?

Extremely premature babies often develop hyperglycemia because their insulin-producing systems are immature. Persistent high blood sugar is associated with increased infection risk, brain damage, and higher mortality. But treating it with insulin is risky because insulin can cause blood sugar to drop too low (hypoglycemia), which can also damage the developing brain.

Could GLP-1 drugs like semaglutide be used for premature babies?

Not yet — this is the very first step in exploring that possibility. This study showed the concept is biologically plausible in rats, but extensive safety and efficacy testing in human neonates would be required before any such treatment could be considered. The drugs' safety profile in adults — where they lower blood sugar without causing hypoglycemia — is what makes this avenue worth exploring.

Read the original research

Incretin effect is sufficient for glucose control in developing rats.

The Journal of endocrinology, 268(1)

View on PubMed ↗Publisher’s paper ↗

Citation

Motokura, Kouji; Tomotaki, Seiichi; Tomobe, Yutaro; Takita, Junko; Kawai, Masahiko. (2026). Incretin effect is sufficient for glucose control in developing rats.. The Journal of endocrinology, 268(1). https://doi.org/10.1530/JOE-25-0146