The virus, medications, or both might be the culprit, experts say
THURSDAY, June 19 (HealthDay News) -- Drugs that suppress HIV are keeping infected individuals alive and relatively healthy for years, even decades. But studies suggest that a new health risk is emerging for these long-term survivors: increased odds for heart attack and stroke.
It's not clear whether the cause is the virus itself or the drugs used to treat it, said Dr. Steven Grinspoon, professor of medicine at Harvard University.
The exact cause of heightened heart risk among HIV patients "may not be just one or the other," he said. "Both may act, in different ways. The drugs may be causing metabolic problems such as dyslipidemia in the traditional way, while the virus can cause inflammation, which is a known factor in atherosclerosis."
Dyslipidemia is an abnormal increase in levels of blood fats such as cholesterol. Having HIV is associated with low levels of "good" HDL cholesterol and high levels of the blood fats called triglycerides, experts have noted.
And studies have shown that HIV drug therapy can cause abnormal accumulations of fat around the organs deep in the abdomen. The U.S. Food and Drug Administration said in March that it was studying the possibility of label changes for two HIV drugs, Ziagen and Videx, because studies showed a higher rate of heart attacks among people taking them.
Whatever the cause, studies, including one led by Grinspoon, show that living with HIV increases the risk of cardiovascular disease by about 70 percent, he said.
"The relative risk is higher for women than for men," Grinspoon said. "It also increases with increasing age. A lot of HIV people are young, so the absolute rates are low, because they are young."
Grinspoon is co-chair of a meeting on HIV and cardiovascular risk, the conclusions of which are reported in both Circulation and the Journal of Acquired Immune Deficiency Syndrome.
"A lot of the studies so far have concentrated on medications," noted Dr. Priscilla Hsue, a cardiologist who is assistant professor of medicine at the University of California, San Francisco, and a member of the group preparing the report. "We've just begun to realize that the virus itself might be responsible. It affects the immune system and results in chronic inflammation, and both have effects on the cardiovascular system."
In terms of prevention, there should be an emphasis on well-known risk factors such as high blood pressure, obesity and smoking, Grinspoon and Hsue said. "We concentrate on smoking, because a lot of [patients with HIV] smoke cigarettes," she said. "But we must work on all the primary risk factors -- weight loss for obesity, family history, diabetes."
One important priority is to develop a cardiovascular risk factor profile that is specific for people infected with HIV, according to Grinspoon.
In terms of primary prevention of heart trouble, Hsue is a strong advocate for the use of daily aspirin. "It is really cheap and very effective at reducing heart attack and stroke," she said.
Close attention to risk factors is one part of "a two-prong approach," the other prong being development of more effective anti-HIV drugs, Grinspoon added. "The drug companies should develop medications with less side effects," he said.
But it is important for HIV-infected individuals to keep taking their HIV-suppressing drugs, he said. At least one study has shown a higher risk for people who went off and then back on HIV therapy, Grinspoon noted.
"It is definitely better to take your HIV medication," he said. "It is very positive. It saves lives."
Find out more on treating HIV infection at the U.S. Department of Health and Human Services.
SOURCES: Steven Grinspoon, M.D., professor, medicine, Harvard Medical School, Boston; Priscilla Hsue, M.D., assistant professor, medicine, University of California, San Francisco; June, 2008, Circulation, Journal of Acquired Immune Deficiency Syndrome
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