• Posted February 5, 2026

Diabetes Drug May Slow Kidney Aging, Study in Fast-Aging Fish Finds

A group of medications often used to treat diabetes may also help protect aging kidneys, according to a new study.

Published recently in the journal Kidney International, the study tested drugs called SGLT2 inhibitors in African turquoise killifish, a small fish that lives only 4 to 6 months. 

Because the fish age so quickly, scientists were able to watch the equivalent of decades of organ aging happen in just weeks.

The results showed that fish given the drugs had healthier kidneys as they grew older.

"These drugs are already known to protect the heart and kidneys in patients with and without diabetes," said senior author Dr. Hermann Haller, president of MDI Biological Laboratory in Bar Harbor, Maine. "What has been less clear is how they do so."

As the killifish aged, their kidneys began to change in ways that looked very similar to aging human kidneys. Researchers saw:

• Loss of tiny blood vessels

• Damage to the kidney’s filtering system

• More inflammation

• Problems with how kidney cells make energy

These same changes are often seen in people with kidney disease.

But fish treated with SGLT2 inhibitors had fewer of these problems. Their kidneys maintained stronger blood flow, healthier filters and more normal energy production inside cells.

The drugs also lowered inflammation and helped kidney cells communicate with each other better.

"Together, these upstream effects provide a biological explanation for clinical observations that the benefits of SGLT2 inhibitors often exceed what would be expected from glucose control alone," Haller said in a news release. 

One of the biggest differences was in small blood vessels. Untreated fish slowly lost these vessels, called capillaries, as they aged. That made it harder for kidney cells to get oxygen, forcing them to rely on weaker backup energy systems.

Fish given SGLT2 inhibitors kept more of these vessels and showed gene activity more like that of younger animals. This was linked to better energy production and less inflammation.

"Seeing these effects emerge so clearly in a rapid-aging model like our killifish was striking," lead author Dr. Anastasia Paulmann of Hannover Medical School in Germany said in a news release.

"What impressed me most was how a seemingly simple drug influences so many interconnected systems within the kidney — from blood vessels and energy metabolism to inflammation and overall function," she added.

SGLT2 inhibitors are already used to treat diabetes and chronic kidney disease. This study helps explain why patients taking these drugs often see heart and kidney benefits.

The researchers say the fast-aging fish could also speed up future studies, allowing scientists to test new treatments much faster than in lab animals like mice.

Next, the team plans to study whether these drugs can help repair kidneys after damage has already started, and whether timing of treatment matters.

More information

The National Institutes of Health has more on aging kidneys.

SOURCE: MDI Biological Laboratory, news release, Jan. 30, 2026