It is difficult to ignore data from prospective studies that involve over 1,000 patients. Some of the data might already be known, but having such a large sample size makes any conclusion almost definitive.

CPCRA is one of the large National Institutes of Health (NIH)-sponsored networks conducting clinical studies related to HIV and its treatment. The main study this network is currently running is called the SMART study. They even have a Web site, www.smart-trial.org, if you are interested in learning more about it. The SMART trial will compare two strategies for the long-term management of antiretroviral therapy:

• the drug conservation (DC) strategy, which is a strategy aimed at conserving drugs through the episodic use of antiretroviral treatment for the minimum amount of time required to maintain a CD4+ cell count of 250 cells/mm³,

  versus

• the viral suppression (VS) strategy, which is a strategy aimed at suppressing viral load as much as possible immediately following randomization and throughout follow up, irrespective of a patient's CD4+ cell count.

The study has enrolled more than 1,300 patients so far.

In the study Drummond et al. presented today, they examined some of the baseline lipid data, as well as the predictors for a low HDL level, which is a known cardiovascular risk factor. They performed a multivariate analysis to try and identify factors that would be associated with a low HDL level, both in the patients not on therapy and in the patients receiving antiretroviral therapy.

In general, being on therapy was associated with having a higher HDL cholesterol level. (It is well known that patients with advanced HIV infection have low HDL levels, as well as high triglyceride levels.) Among patients on treatment, those receiving NNRTIs were more likely to have higher HDL levels. Higher HIV RNA viral load numbers and high triglyceride levels were also associated with low HDL levels in treatment-naive patients. In patients on treatment, high triglyceride levels and diabetes were associated with low HDL levels.

The results are not earth shattering, but confirm the prevailing wisdom in the field. The bottom line is that it is quite common for patients with HIV infection to have multiple risk factors for cardiovascular disease. Data recently published in the New England Journal of Medicine¹ suggest that HIV-positive patients on treatment have a higher incidence of cardiovascular events.

Clearly, it is important both for patients and physicians to be aware of this fact. Clinicians should review each patient's individual risk factors in order to intervene if necessary. Cardiovascular risk is an important variable to take into consideration when selecting antiretroviral therapy, since currently available treatments for HAART-associated hyperlipidemia have limited efficacy. Several studies presented at this meeting looked at possible treatments: ACTG 5087 looked at the efficacy of pravastatin, fenofibrate or both (Poster 723), and another study from the University of North Carolina examined the use of fish oil (Poster 724). However, they had only partial effectiveness.

Footnote

1. The Data Collection on Adverse Events of Anti-HIV Drugs (DAD) Study Group, Combination Antiretroviral Therapy and the Risk of Myocardial Infarction, NEJM 2003; 349:1993-2003.

Reference

Abstract: Predictors of Low HDL in HIV-Positive Patients: Effect of Class of Antiretroviral Therapy and Traditional Risk Factors (CPCRA 065) (Poster 712)
Authored by: F. Drummond, C. Mullin, M. Poehlman, SMART Protocol Team, The Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA 065)
Affiliations: Univ. of New South Wales, Sydney, Australia; Univ. of Minnesota, Minneapolis, MN