March 3, 2009

Study: Reyataz Negatively Affects Blood Vessel Function

The protease inhibitor Reyataz (atazanavir) negatively affects the normal functioning of blood vessels, as has been seen with other protease inhibitors, according to a study published in the May 2009 issue of Heart. The authors suggest that Reyataz reduces the ability of arteries to widen (dilate), a sign of cardiovascular disease (CVD) tied to plaque buildup in the blood vessels.

Reyataz has gained favor among many physicians because it is the protease inhibitor least likely to cause unhealthy changes in cholesterol and triglycerides, which in turn can lead to heart disease. More recently, however, factors other than cholesterol have been fingered as possible CVD culprits in people living with HIV, including impaired blood vessel functioning.

Andreas Flammer, MD, from the University Hospital Zurich in Switzerland and his colleagues focused on one measure of blood vessel health, called flow-mediated dilation (FMD), in people taking Reyataz and other protease inhibitors. When blood vessels are functioning properly, they widen, or dilate,  when blood flows more heavily through them. Among other things, this helps keep blood pressure roughly equal in all parts of the body and ensures a regular supply of oxygen to the brain and the limbs. Researchers in the past decade found that people whose blood vessels have a reduced ability to dilate are more likely to have heart problems.

Flammer and his colleagues randomized 39 HIV-positive people taking a protease inhibitor other than Reyataz to either continue with their regimen unaltered or to switch to Reyataz. Of note, those taking Reyataz did not use low-dose Norvir—a protease inhibitor that has been tied to a higher CVD risk in HIV-positive people.

Flammer’s team measured the impact of the switch on FMD. They found that FMD negatively decreased in both groups to an almost identical degree, despite the fact that people who switched to Reyataz had improvements in cholesterol and triglycerides.

The authors concluded that reductions in FMD might have a negative impact on blood vessels and ultimately the heart. Further research is needed to confirm this finding and determine what, if any, effect Reyataz may have on blood vessel function and heart disease risk.

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Previous Comments:

John, Orlando, 2009-03-06 01:36:29
Following on the question above, I'd be curious to find out if drugs such as Viagra would not be advised.

Rebecca, anywhere, usa, 2009-03-05 11:46:20
I am glad that there are real DOCTORS left out there, CVD must be on the rise because I have read tons of info in the last 6 mos. Funny how my USA doctor swears I don't know what I am talking about and I should just shut up and be happy my numbers are good. Well if I wasn't a 20+ PWA survivor about to turn 50, tommorrow in fact, I would be if I felt like the "numbers". My doc makes me feel that is all that matters to them. Oh, they want to know if I ACTIVE!, wish I could go live in Sweden.

Gary Barton, West Hollywood, 2009-03-04 12:02:04
For a few years, on a daily basis, I get flair ups of inflammation where the palms of my hands, the very top of my chest (to the neck) and sometimes other parts of the body, get bright red for no apparent reason. I am also having some SaO2 at higher altitudes (e.g in airplanes). Could either of these things be caused by Reyataz w/ low dose Norvir?

Tim Horn, New York, NY, 2009-03-04 09:18:22
Solouno, Your question is a good one. Studies reported in 1999/2000 did show that a significant percentage of PLWHIV using PIs began experiencing erectile dysfunction. However, nobody has ever shown that PIs actually cause this problem, for which there are many possible culprits. While this study -- and others looking at links between PIs and blood vessel dilation -- suggest a possible mechanism, they are by no means conclusive. Let's hope for more research going forward.

solouno, Detroit, 2009-03-03 21:11:48
This new information can lead one to believe that Reyataz can also cause Erectile Dysfunction. Does anyone know if this is true?