TUESDAY, April 24, 2007 (HealthDay News) -- People infected with HIV face nearly twice the risk of heart attack that non-infected individuals do, a new study suggests.
That risk remained elevated even after researchers accounted for age, high blood pressure, high cholesterol and other cardiovascular risk factors, suggesting that the virus itself or therapies used to treat it might somehow be harming the heart.
"We don't mean to scare people off their meds -- they need to take the meds to survive. But doctors should also be aware of this increased risk," said senior researcher Dr. Steven Grinspoon, an associate professor of medicine at Harvard Medical School.
His team reported the findings Tuesday in the online edition of the Journal of Clinical Endocrinology and Metabolism.
The link between HIV, the virus that causes AIDS, and heart disease isn't new, noted Rowena Johnston, vice president of research at the Foundation for AIDS Research (amfAR), based in New York City.
"We have certainly suspected that for a long time," she said. In fact, one major European study, the Data Collection on Adverse Events of Anti-HIV Drugs (DAD), reported back in 2005 that HIV-positive patients had nearly twice the risk of heart attack compared to uninfected individuals of similar age.
But the new study involved even more powerful statistics. In its work, Grinspoon's team analyzed demographic and diagnostic data for more than 1.7 million patients treated at Massachusetts General Hospital (MGH) and Brigham and Women's Hospital, both in Boston, since 1993.
They compared eight years of outcomes data for almost 4,000 HIV-infected patients, aged 18 to 84, with information on more than 1 million uninfected patients.
Overall, HIV-positive patients had nearly twice the risk of suffering a heart attack compared to age-matched controls, the researchers found. Those risks were especially high for women, whose odds of heart attack nearly tripled once they became infected, even after the researchers adjusted for age and heart disease risk factors such as high blood pressure, high blood cholesterol and diabetes.
In contrast, infected men had a 40 percent increase in their odds for heart attack after compensating for those risk factors.
"We don't why that is -- whether women have more serious metabolic changes or not," said Grinspoon, who also directs Massachusetts General Hospital's Program in Nutritional Metabolism. "Traditional risk factors may be accounting for more of the (heart attack) rates in women than in men, and there may be other things related to body composition that we couldn't factor in."
HIV-infected black patients also had higher heart attack risk than their white peers, the study found. That finding echoes trends among non-HIV-infected heart patients.
Could HIV infection, on its own, raise heart risks? The experts aren't sure.
"HIV is a virus, so (infection) is an inflammatory state," Grinspoon said. Chronic inflammation has recently been linked to cardiovascular disease, so "one hypothesis would be that these patients have a pro-inflammatory condition," he said.
Of course, most of the patients in the study were also taking the powerful cocktail of HIV-suppressing drugs collectively known as "highly active antiretroviral therapy" (HAART).
On the one hand, "HAART suppresses inflammation, which can improve cardiovascular parameters," Grinspoon noted. "But, on the other hand, treatment with HAART also leads to worsening changes in body composition and has even more adverse effects on (blood) glucose, lipids, etcetera. So, it's a mixed bag."
Other factors may also boost heart risk for people with HIV, Johnston added.
She noted that study participants who were infected with HIV tended to smoke more, which isn't surprising given the stresses of living with the virus. Smoking remains a major risk factor for heart disease.
Johnston emphasized that the findings should not make patients wary of taking their medications.
"There's no doubt that antiretroviral therapy is saving lives, regardless of whether there's an increase in (heart attack)," she said. "The benefits of antiretroviral therapy certainly outweigh those risks."
But Johnston said that doctors who care for people living with HIV need to be "vigilant" in tracking their cardiovascular health.
"Doctors need to be aware of this increased risk, and that it occurs even among young HIV patients," he said. "Sometimes with (young) patients who might have chest pain, you might not ordinarily be concerned, but we are suggesting that doctors pay serious attention to that, because there is this increased risk of cardiovascular disease."
Find out more about the fight against HIV/AIDS at amfAR.