A studies of diabetes drugs known as DPP-4 reported mixed results in terms of medications’ impact on patients’ hearts.

Theses drugs, such as Onglyza, Nesina and Januvia, work by inhibiting dipeptidyl peptidase-4, to enhance the body’s ability to lower elevated levels of blood sugar. While DPP-4s are not the most powerful agents for lowering blood sugar levels, they are well tolerated and have proved an attractive option for doctors looking for new oral drugs.

However, according to detailed results of a Onglyza study of 16,492 patients and presented at the European Society of Cardiology annual congress in Amsterdam, researchers found that there was no overall increase in cardiovascular risks associated with the medication, however the pills might be linked to heart failure; where the heart fails to pump blood adequately. This is because the Onglyza research found a small increase in the level of hospitalizations for heart failure (it affected 3.5 percent of those taking the drug compared to 2.8 percent in the control group).

A smaller study of 5,380-patients taking another drug in the classification, Nesina, offered alongside the Onglyza at the ESC did not cause the same problem, most likely said Onglyza co-principal investigator because the second study was smaller.

Researchers were hoping that the DPP-4 drugs would be beneficial to the heart, because diabetes patients are tend to be at risk for heart problems.