(HealthDay is the new name for HealthScoutNews.)
TUESDAY, July 1, 2003 (HealthDayNews) -- Patients with diabetes and heart failure seem to be routinely receiving medications that may aggravate one condition even if they help the other.
Specifically, metformin (brand name Glucophage) and a class of medications called thiazolidinediones -- both of which help control glucose levels in diabetics -- may cause serious complications in patients with heart failure.
The findings are detailed in a study in the July 2 issue of the Journal of the American Medical Association.
"The number of patients with diabetes has increased dramatically in the country over the last 10 years and increasingly these medications are being used as part of their therapy," says Dr. Sid Smith, director of the Center for Cardiovascular Science and Medicine at the University of North Carolina.
"Because of the observations of fluid retention and weight gain [in the case of thiazolidinediones], it's very important that they not be used in patients with known heart failure or, if necessary, that possible problems be monitored very carefully," adds Smith, who is a past president of the American Heart Association.
Part of the problem is that so many patients, especially patients with diabetes, have other health conditions as well.
"The typical heart failure patients are patients who have many concurrent illnesses and complications and can end up on a lot of different medications," says study author Dr. Harlan M. Krumholz, a professor of medicine and epidemiology and public health at Yale University School of Medicine.
"As people end up going to a specialist, there's often not a lot of cross-talk. We need to pay a lot more attention to the integration of our approaches and taking into account a variety of conditions," Krumholz says.
But there's also the issue of whether physicians are paying attention to U.S. Food and Drug Administration (FDA) "black box" warnings on medications. Such warnings are the most serious category of health side effects.
"There's a discordance between what the FDA is saying and what's going on in practice," Krumholz says. "We're potentially undermining the entire system."
The black-box warning for metformin indicates the drug could lead to lactic acidosis -- or acid in the blood, a potentially life-threatening problem for people with heart failure. And thiazolidinediones may cause fluid retention, again a serious condition for heart failure patients.
"Good care of a chronic condition of heart failure entails getting people into the right balance. And if they're on medications that cause them to retain fluid, it may turn them in the wrong direction and tip them over and cause them to be hospitalized," Krumholz says.
For this study, Krumholz and his colleagues pored through the medical records of Medicare beneficiaries who had been hospitalized with heart failure and diabetes from April 1998 to March 1999 and July 2000 to June 2001.
The earlier sample consisted of 12,505 patients, 7.1 percent of whom were discharged with a prescription for metformin, 7.2 percent with a prescription for a thiazolidinedione, and 13.5 percent with a prescription for one or the other.
In the second sample, which consisted of 13,158 patients, 11.2 percent got metformin, 16.1 percent got a thiazolidinedione, and 24.4 percent one or the other.
The study authors did not look at how many people had adverse reactions, simply how many patients were prescribed the drugs.
It's not entirely clear why this disconnect is happening, the researchers say. Physicians may simply not be aware of the dangers or they may think the benefits outweigh the risks. Or they may have decided that the risks aren't as high as advertised.
"We have a problem when the FDA is saying one thing with respect to the safety of a medication and clinicians are so frequently doing something else," Krumholz says.
"We need to determine the best way to treat patients," he says. "It is a problem when the FDA's black-box warning is not being heeded. Either the FDA has overreacted or clinicians are exposing their patients to unnecessary risk, and we [have] to know which it is."
And it's not just an issue for heart failure patients with diabetes, although this is a group that warrants more attention.
"It raises the issue about the way that we deliver health care in this country," says Dr. Kenneth Hupart, chief of endocrinology, diabetes and metabolism at Nassau University Medical Center in East Meadow, N.Y.
"Are we either having doctors who are generalists taking care of these complicated illnesses too much, or are we balkanizing it too much and having super-specialists taking care of [patients] and sometimes lacking the broad picture? We have to reexamine the way we provide health care to people in this country. We can hypothesize but we can't really know from a study like this. It invites further studies."
More information
Both the American Diabetes Association and the American Heart Association have information on the connection between heart disease and diabetes.
