BOSTON, Aug. 21 -- Heavy alcohol use appears to speed HIV progression, researchers here said.
But the effect is modest and is only seen in HIV-infected people not getting anti-retroviral therapy (ART), according to Jeffrey Samet, M.D., of Boston University, and colleagues.
Nevertheless, the finding suggests that people with HIV should avoid heavy alcohol consumption, they reported online in the Journal of Acquired Immune Deficiency Syndromes.
"HIV-infected persons who drink alcohol heavily and are not on ART might decrease their risk of disease progression if they abstain from alcohol use," the researchers said.
The finding emerged from two prospective observational cohort studies, which ran consecutively from 1997 through 2001 and 2001 through 2006, to investigate links between alcohol use and HIV progression.
Some of the participants in the first study were also recruited for the second, and the combined cohort included 595 people. Participants had HIV and either past or current alcohol problems at enrollment.
The researchers defined heavy drinking as:
- More than 14 drinks a week or at least five drinks on a single occasion for men younger than 66.
- More than seven drinks a week or at least four drinks on a single occasion for men 66 or older.
- More than seven drinks a week or at least four drinks on a single occasion for all women.
Moderate alcohol use was defined as any drinking less than heavy amounts.
The participants were assessed at study enrollment and then every six months for CD4 cell counts and HIV RNA levels and for alcohol use within the previous 30 days.
Overall, the researchers said, 30% of participants were heavy consumers, 10% were moderate, and 59% were abstinent. Among those who reported drinking in the 30 days before an assessment, the average daily alcohol consumption was 5.4 drinks.
When the researchers looked at those not on ART, they found that the adjusted mean CD4-positive T-cells averaged 48.6 cells per microliter lower for those with heavy alcohol use than for those who were abstinent. The difference was statistically significant at P=0.03.
On the other hand, there was no difference in viral load, Dr. Samet and colleagues found. Also, there was no association between moderate drinking and disease progression.
Heavy alcohol use is known to lessen adherence to therapy, which in turn increases the risk of HIV progression, the researchers noted.
But among study participants on ART -- when the researchers controlled for adherence to therapy -- there was no association between drinking and either disease progression marker.
One explanation for that might be that the large beneficial effect of the therapy outweighs the small negative effect of the alcohol, Dr. Samet and colleagues said.
The study is unable to say much about moderate drinking, the researchers said, because only 10% of participants reported that level of alcohol consumption.
That's not surprising, given that the study included people with alcohol problems: "Individuals with current or past alcohol dependence are likely to abstain or drink heavily," the researchers said.