Lower Blood Alcohol Concentration Among HIV-Positive Versus HIV-Negative Individuals Following Controlled Alcohol Administration

Background: Although it has been purported that HIV-positive individuals may experience a greater degree of intoxication than HIV-negative individuals following acute alcohol consumption, no research to date has empirically tested this supposition. The present investigation entailed a randomized controlled experiment to identify whether the administration of a weight-specified dose of alcohol would lead to differential blood alcohol concentrations (BACs) among HIV-positive versus HIV-negative men. Methods: In a specialized barroom laboratory, 143 men (n = 76 HIV-positive and n = 67 HIV-negative; mean age = 42.9) consumed beverages based on a formulation of 0.7 g alcohol/kg body weight over a 15-minute time frame. BAC was assessed via breathalyzer at 2 set time points (10 and 13 minutes postconsumption) and then periodically until detoxification (BAC < 0.040%). Primary outcomes included (i) area under the curve (AUC), calculated based on all of one's BAC readings, (ii) "BAC-EXP," defined as one's BAC reading 13 minutes postconsumption, and (iii) BAC-PEAK, defined as one's highest recorded BAC reading. Results: Contrary to predictions, AUC (t(141) = 2.23, p = 0.027), BAC-EXP (t(141) = 2.68, p = 0.008), and BAC-PEAK (t(141) = 2.29, p = 0.023) were significantly lower among HIV-positive versus HIV-negative participants. These effects were sustained in multivariable models controlling for age, race, and AUDIT-based hazardous drinking classification. Among the HIV-positive sample, outcomes did not significantly differ based on HIV viral load detectability, antiretroviral therapy (ART) status, or ART adherence. Conclusions: The administration of a controlled, weight-specified dose of alcohol led to lower BACs among HIV-positive versus HIV-negative participants. These differences might derive from decreased body fat percentage and delayed gastric emptying associated with HIV seropositivity; however, additional research is necessary to verify these mechanisms. Unique alcohol dosing formulas based on HIV serostatus may be required in future alcohol administration experiments involving HIV-positive samples.