D:A:D results: Higher CD4 cell counts linked to lower mortality among patients with HIV

MONTREAL — Maintaining high CD4 cell counts may have the “broadest effect” in reducing the risk of mortality among patients with HIV, according to results of the D:A:D study, presented at the 16th Annual Conference on Retroviruses and Opportunistic Infections, held here.

Results of the D:A:D study, designed to examine multiple mortality risk factors among patients with HIV, also indicated that several potentially modifiable risk factors were also significantly associated with mortality risk among patients with HIV.

The D:A:D study included data for 33,347 patients with HIV comprising a total of 158,959 person-years. The study also examined various modifiable risk factors for mortality, including hepatitis, body mass index, smoking, hypertension, diabetes, ART use, CD4 counts and HIV RNA. The data were adjusted for other potential confounders, including age, sex, race and prior cardiovascular disease.

A total of 2,192 deaths were reported. According to the results, underlying causes of death were AIDS (32%), liver related (14%), non-AIDS cancers (12%), CVD (11%) and other (31%).

The results demonstrated that mortality risk was affected by other various modifiable factors, including smoking, low body mass index, hypertension, diabetes, hepatitis coinfection, low CD4 cell count and higher HIV RNA.

The strength of these modifiable risk factors on mortality varied significantly by cause-specific death, according to the researchers. Smoking was associated with cardiovascular disease and non-AIDS cancers, hepatitis coinfection with liver-related deaths, diabetes with all causes but non-AIDS cancers, higher HIV RNA with AIDS and liver-related deaths. Lower CD4 counts were associated with a higher risk of death from all causes of death. – by Jay Lewis

This study's results underscore the importance of addressing modifiable risk factors in patients with HIV to reduce mortality in this population. They also add to an increasing body of evidence that control of HIV replication and higher CD4+ T-cell counts related to ART may reduce the risk of non-HIV-related morbidity and mortality. Nevertheless, these data must be interpreted cautiously as they are observational and therefore subject to confounding. Prospective randomized trials would be necessary to definitively determine whether earlier initiation of antiviral therapy is optimal.

– Elizabeth Connick, MD

Infectious Disease News Editorial Board member

For more information:

Smith C. #145. Presented at: the 16th Annual Conference on Retroviruses and Opportunistic Infections; Feb. 8-11, 2009; Montreal.