Researchers are reporting at an international cardiology conference that a newer class of diabetes drugs won't raise risk for heart attacks, a worry that has previously been associated with diabetes medications.
However the two studies, presented Monday at the European Society of Cardiology 2013 Congress, also showed the drugs did not lower risk for heart problems as some experts had hoped.
"While it is reassuring that evidence does not suggest (cardiovascular concerns), it is disappointing that none of these therapies provide CV benefit," Dr. Sanjay Kaul, a cardiologist at Cedars-Sinai Medical Center in Los Angeles who co-wrote a commentary of the studies, said to the Wall Street Journal.
The heart safety associated with these drugs, so-called "dipeptidyl peptidase 4 inhibitors (DPP-4)," had been largely unclear, according to the researchers. While the drug's overall had safe profiles, one of the trials found an elevated risk of hospitalization for heart failure that may give some pause.
The two safety studies involved a new class of drugs aimed at treating a chronic disease that as many as 26 million Americans may have, Type 2 diabetes.
People with Type 2 diabetes either do not produce enough insulin to break down sugar (glucose) or the insulin that is present is ignored by cells. Over time, high glucose levels can cause wide-ranging health problems, affecting other areas like the eyes, kidneys, nerves and heart.
According to the authors of the first trial, there's been speculation that DPP-4 medications may benefit heart health.
The first study looked at alogliptin, which is marketed by Takeda Pharmaceutical and Sanofi SA as Nesina.Takeda also funded the study.
Researchers randomly assigned nearly 5,400 diabetics who had recently suffered a heart attack or had chest pains to receive either alogliptin or a placebo, dummy pill for 90 days in addition to their existing treatments.
They were looking for whether nonfatal heart events or strokes occurred during the study period. The research revealed 305 people taking the drug had a heart event, compared to 316 who were taking the placebo.
That means taking the drugs didn't make heart health worse -- but alogliptin didn't decrease risk for heart problems either.
Drug-takers did have "modestly better" blood sugar levels than those taking the placebo pills.
"The findings could guide clinicians to choose among the many anti-diabetic agents available when treating patients with Type 2 diabetes and very high cardiovascular risk, concluded the study's authors, led by Dr. William B. White, chief of the division of hypertension and clinical pharmacology at the University of Connecticut Health Center in Farmington, Ct.
But, the researchers added the results of the study, which tracked participants for about 18 months after drug treatment, do not rule out long-term heart benefits or risks in people taking on alogliptin.
The next trial looked at the DPP-4 inhibitor saxagliptin, marketed by AstraZeneca and Bristol-Myers Squibb as Onglyza. It involved more than 1,200 patients, divided into two groups to receive either the drug or a placebo. AstraZeneca and Bristol-Myers Squibb funded the study.
Similar to the other paper, the researchers were looking for heart events in pill-takers.
The researchers found people taking saxagliptin did not experience increased or decreased risks for heart problems including heart attack, stroke and chest pains. They found, however, an increased risk for hospitalization caused by heart failure that was not due to chance.
"I think what we have provided in this trial is a great deal of clarity with respect to heart-attack risk," Dr. Deepak Bhatt, a senior physician at the Brigham & Women's Hospital in Boston who presented the study at the conference, said to the Wall Street Journal. "But this heart-failure finding was unexpected. For that reason, it's important to be a little bit cautious in interpreting it."
Dr. Christopher Granger, director of the cardiac care unit at Duke University Medical Center in Durham, N.C., and was not involved in the study, said to Reuters that finding was a bit concerning. "I'm sure the FDA will want to know more about it," he said.
In addition to the medical conference, the studies were published Sept. 2 in the New England Journal of Medicine.
Heart health concerns from diabetes drugs have gained attention in recent years, notably when one of the top-selling diabetes medications in the world --
Adults with diabetes as is are two to four times more likely to have heart disease than those without, the American Diabetes Association points out.
Granger told MedPage Today, that despite the increased heart failure risk, both studies were "reassuring" and reflected the "the first wave in what the FDA is now requiring for all diabetes drugs -- cardiovascular safety studies."