A study has found that long-term usage of type 2 diabetes drug liraglutide can weaken insulin-producing cells and result in increased production of blood sugar.

Incretin hormone GLP-1 equivalents are used to suppress blood sugar levels in treatments for type 2 diabetes. These GLP-1 equivalents fuel the pancreatic beta cells' response to glucose in order to release more insulin.

Swedish researchers from the Karolinska Institutet and American researchers from the University of Miami in the U.S. have analyzed the effects of liraglutide in mice transplanted with insulin-producing cells. In the study, the mice were given liraglutide doses daily for more than 250 days to monitor the gradual blows to the pancreatic beta cells. The effect of liraglutide lowered the blood sugar levels but later causes a degenerative exhaustion among insulin-producing cells.

"Given the lack of clinical studies on the long-term effect of these drugs in diabetes patients, this is a very important discovery," said Diabetes Research Institute researcher Midhat Abdulreda from the University of Miami Miller School of Medicine.

Study author and Karolinska Institutet professor Per-Olof Berggren said it is vital to consider these findings prior to the prescription of drugs with GLP-1 equivalents, especially in long-term therapies for diabetes patients.

Berggren added that their research provides information on how to conduct studies that analyze long-standing consequences of treatments on insulin-producing cells, which should be valuable to the drug industry. The findings were published in the Cell Metabolism journal on Feb. 11.

Liraglutide is an FDA-approved drug marketed as Victoza. It is used for the treatment of type 2 diabetes as an addition to exercise and a diet regimen. It is important to note that liraglutide is not recommended as an initial treatment for type 2 diabetes patients with insufficient glycemic control through exercise and diet and should not be used to treat patients with diabetic ketoacidosis and type 1 diabetes since the drug will not be as effective.

The research was funded by the Diabetes Research Institute Foundation, Swedish Research Council, National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases, Family Erling-Persson Foundation, European Research Council, Knut and Alice Wallenberg Foundation, Stichting af Jochnick Foundation and the Novo Nordisk Foundation.

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