Untreated HIV Associated With Less-"Elastic" Arteries, Raising Heart Disease Risk, Study Finds

We know all too well that HIV causes bad things to happen in your body. But lately, we've seen increasing evidence that it particularly affects your heart. A new study published in the September 2009 issue of the Journal of Acquired Immune Deficiency Syndromes adds to this evidence by showing that, compared to HIV-negative people, HIV-positive people who are not taking HIV medications are more likely to have less "elastic" arteries, which increases the chances they will develop heart disease.

A healthy artery should be like a balloon and stretch easily (i.e., be elastic). Low elasticity is associated with a hardening of the arteries. This is known as atherosclerosis, which is a marker of heart disease risk.

For the study, Minneapolis researchers used a unique, relatively new, non-invasive research tool called "pulse waveform analysis" to assess the elasticity of people's arteries. Jason Baker, M.D., the study's lead investigator, says it is a promising, "new technique to study heart disease risk in persons with HIV before they develop symptoms of clinically apparent disease."

The researchers recruited two groups: The first group consisted of 32 HIV-positive people not on HIV treatment, while the second group of 30 were HIV-negative people (the "controls"). Using pulse waveforms, the researchers compared the differences in the volunteers' elasticity scores. To make sure that their results weren't skewed, they took into consideration all sorts of known heart disease risk factors, such as smoking, hepatitis C infection, race/ethnicity, drug use, cholesterol levels, age and sex.

The researchers found that there was significantly less arterial elasticity in the HIV-positive participants than the HIV-negative participants. "This suggests that untreated HIV infection is causing damage to the arterial wall, rendering it less elastic (more stiff), which is a process linked to an increased risk for heart disease," explains Keith Henry, M.D., the director of HIV Research at Hennepin County Medical Center and one of the authors of the study. Neither CD4 count nor viral load level appeared to have any impact on the amount of lost elasticity in the arteries among the HIV-positive participants.

This finding is not an unexpected one, since research has shown repeatedly that HIV is bad for the heart in people with HIV who are not on treatment. However, what makes this study unique is that it looks more deeply into some of the badness that we already knew about -- and it may also provide valuable insight into how HIV harms the heart. "This observation may help understand the mechanism by which HIV is causing damage to the circulatory system and serve as a non-invasive marker for the damage," noted Dr. Henry, although he added that more studies are needed to confirm the findings.