Protocol for a Controlled Experiment to Identify the Causal Role of Acute Alcohol Consumption in Condomless Sex among HIV-Positive MSM: Study Procedures, Ethical Considerations, and Implications for HIV Prevention

The Role of Alcohol-Related Behavioral Research in the Design of HIV Secondary Prevention Interventions in the Era of Antiretroviral Therapy: Targeted Research Priorities Moving Forward

HIV secondary prevention focuses on averting onward HIV transmission, which can be realized when people living with HIV enact requisite HIV care continuum-related behaviors to achieve viral suppression, and engage in condom-protected sex when virally unsuppressed. Alcohol has been detrimentally linked to all aspects of HIV secondary prevention, and although a growing number of behavioral interventions account for and address alcohol use within this realm, further efforts are needed to fully realize the potential of such initiatives. The present article proposes a series of targeted priorities to inform the future design, implementation, and evaluation of alcohol-related behavioral intervention research within the scope of HIV secondary prevention. These priorities and corresponding approaches account for the challenges of resource-constrained clinic environments; capitalize on technology; and address key comorbidities. This framework provides the foundation for a range of alcohol-related behavioral interventions that could potentially enhance global HIV secondary prevention efforts in the years ahead.

Alcohol Use and the Risk of Communicable Diseases

The body of knowledge on alcohol use and communicable diseases has been growing in recent years. Using a narrative review approach, this paper discusses alcohol's role in the acquisition of and treatment outcomes from four different communicable diseases: these include three conditions included in comparative risk assessments to date-Human Immunodeficiency Virus (HIV)/AIDS, tuberculosis (TB), and lower respiratory infections/pneumonia-as well as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) because of its recent and rapid ascension as a global health concern. Alcohol-attributable TB, HIV, and pneumonia combined were responsible for approximately 360,000 deaths and 13 million disability-adjusted life years lost (DALYs) in 2016, with alcohol-attributable TB deaths and DALYs predominating. There is strong evidence that alcohol is associated with increased incidence of and poorer treatment outcomes from HIV, TB, and pneumonia, via both behavioral and biological mechanisms. Preliminary studies suggest that heavy drinkers and those with alcohol use disorders are at increased risk of COVID-19 infection and severe illness. Aside from HIV research, limited research exists that can guide interventions for addressing alcohol-attributable TB and pneumonia or COVID-19. Implementation of effective individual-level interventions and alcohol control policies as a means of reducing the burden of communicable diseases is recommended.

Alcohol and Sexual Health Behavior: "What We Know and How We Know It"

Alcohol, despite salutary associations with sexuality, has been implicated in sexual health problems. This review examines the relationship between alcohol and outcomes related to sexual health. Methodological considerations limiting causal assertions permissible with nonexperimental data are discussed, as are advantages of experimental methods. Findings from laboratory experiments are reviewed evaluating causal effects of acute alcohol intoxication on a variety of outcomes, including sexual arousal, sexual desire, orgasm, and sexual risk behaviors related to sexually transmitted infections (STIs) and human immunodeficiency virus (HIV). Several variables exerting mediating and moderating influences are identified. It is concluded that acute alcohol intoxication is capable of exerting a causal impact on multiple constituent components of sexual responding related to sexual health. Both alcohol expectancy and alcohol myopia theories have been supported as explanations for these causal effects. Furthermore, for sexual risk behavior, noteworthy recent developments include research highlighting the importance of women's sexual victimization history and men's condom use resistance. Limitations and implications associated with this body of research are also discussed.

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.

Meta-Analysis of Alcohol and Serodiscordant Condomless Sex Among People Living with HIV

While observational studies have found that alcohol consumption is associated with serodiscordant condomless sex among people living with HIV (PLHIV), no meta-analysis has yet examined this trend. We conducted a meta-analysis to synthesize empirical evidence on the association between alcohol and condomless sex with partners at risk of HIV acquisition. To meet inclusion criteria, studies: (1) specifically targeted PLHIV or provided stratified data for HIV-infected participants; (2) provided a quantitative measure of alcohol use; (3) provided a quantitative measure of condomless sex with serodiscordant partners; and (4) reported the results of statistical tests examining the relationship between alcohol use and serodiscordant condomless sex. Using random-effects models, weighted effect sizes were calculated. Three separate analyses were conducted to examine serodiscordant condomless sex in association with any alcohol consumption, binge/problematic drinking, and alcohol in a sexual context. A total of 36 independent effect sizes from 27 studies (including 25,065 HIV-infected participants) were pooled in the meta-analysis. Any alcohol consumption, binge/problematic drinking, and alcohol use in a sexual context were each associated with condomless sex with serodiscordant partners [OR 1.64 (95% CI 1.46-1.85); OR 1.65 (95% CI 1.14-2.39); OR 2.88 (95% CI 2.01-4.12), respectively]. Meta-analytic findings demonstrate a consistent positive relationship between alcohol use and serodiscordant condomless sex among PLHIV. Future public health programming for HIV-infected individuals needs to address the role of alcohol consumption in sexual risk-taking behavior.

Acute Alcohol Consumption Directly Increases HIV Transmission Risk: A Randomized Controlled Experiment

BACKGROUND

Alcohol consumption has frequently been purported as a driver of condomless sex and HIV transmission, but to date, experimental evidence for the causal risk-taking impact of alcohol among HIV-positive populations is lacking. The present experiment sought to determine whether acute alcohol consumption has a direct causal impact on condomless sex intentions among HIV-positive men-who-have-sex-with-men (MSM), and to assess whether alcohol's impact differs between MSM who are HIV-positive versus HIV-negative.

METHODS

In a randomized controlled alcohol administration experiment, HIV-positive and HIV-negative MSM were brought into a specialized barroom laboratory and randomly assigned to beverage consumption condition: alcohol (target blood alcohol concentration = 0.080%), placebo alcohol (target blood alcohol concentration = 0.000%), or water (control). Participants then underwent a video-based sexual arousal manipulation (sexually aroused/nonaroused) and indicated their intentions to engage in condom-protected and condomless sexual acts in a standardized paradigm. The primary outcome entailed intentions to engage in condomless receptive and condomless insertive anal sex.

RESULTS

A total of 282 MSM (141 HIV-positive; 141 HIV-negative) completed experimental procedures. MSM who received alcohol reported significantly stronger intentions to engage in condomless sex than those who received placebo alcohol or water (F(1,274) = 9.43, P = 0.002). The impact of alcohol did not differ between HIV-positive and HIV-negative MSM (F(1,274) = 1.86, P = 0.174).

CONCLUSIONS

The present investigation entailed the first risk-focused alcohol administration experiment to involve an HIV-positive sample, and results demonstrated that consuming alcohol had an independent, causal impact on intentions to engage in sexual behaviors that can result in HIV transmission. Findings strongly suggest that alcohol-focused initiatives should be incorporated into HIV prevention efforts.

The relationship between different dimensions of alcohol use and the burden of disease-an update

BACKGROUND AND AIMS

Alcohol use is a major contributor to injuries, mortality and the burden of disease. This review updates knowledge on risk relations between dimensions of alcohol use and health outcomes to be used in global and national Comparative Risk Assessments (CRAs).

METHODS

Systematic review of reviews and meta-analyses on alcohol consumption and health outcomes attributable to alcohol use. For dimensions of exposure: volume of alcohol use, blood alcohol concentration and patterns of drinking, in particular heavy drinking occasions were studied. For liver cirrhosis, quality of alcohol was additionally considered. For all outcomes (mortality and/or morbidity): cause of death and disease/injury categories based on International Classification of Diseases (ICD) codes used in global CRAs; harm to others.

RESULTS

In total, 255 reviews and meta-analyses were identified. Alcohol use was found to be linked causally to many disease and injury categories, with more than 40 ICD-10 three-digit categories being fully attributable to alcohol. Most partially attributable disease categories showed monotonic relationships with volume of alcohol use: the more alcohol consumed, the higher the risk of disease or death. Exceptions were ischaemic diseases and diabetes, with curvilinear relationships, and with beneficial effects of light to moderate drinking in people without heavy irregular drinking occasions. Biological pathways suggest an impact of heavy drinking occasions on additional diseases; however, the lack of medical epidemiological studies measuring this dimension of alcohol use precluded an in-depth analysis. For injuries, except suicide, blood alcohol concentration was the most important dimension of alcohol use. Alcohol use caused marked harm to others, which has not yet been researched sufficiently.

CONCLUSIONS

Research since 2010 confirms the importance of alcohol use as a risk factor for disease and injuries; for some health outcomes, more than one dimension of use needs to be considered. Epidemiological studies should include measurement of heavy drinking occasions in line with biological knowledge.

The relationship between different dimensions of alcohol use and the burden of disease-an update

BACKGROUND AND AIMS

Alcohol use is a major contributor to injuries, mortality and the burden of disease. This review updates knowledge on risk relations between dimensions of alcohol use and health outcomes to be used in global and national Comparative Risk Assessments (CRAs).

METHODS

Systematic review of reviews and meta-analyses on alcohol consumption and health outcomes attributable to alcohol use. For dimensions of exposure: volume of alcohol use, blood alcohol concentration and patterns of drinking, in particular heavy drinking occasions were studied. For liver cirrhosis, quality of alcohol was additionally considered. For all outcomes (mortality and/or morbidity): cause of death and disease/injury categories based on International Classification of Diseases (ICD) codes used in global CRAs; harm to others.

RESULTS

In total, 255 reviews and meta-analyses were identified. Alcohol use was found to be linked causally to many disease and injury categories, with more than 40 ICD-10 three-digit categories being fully attributable to alcohol. Most partially attributable disease categories showed monotonic relationships with volume of alcohol use: the more alcohol consumed, the higher the risk of disease or death. Exceptions were ischaemic diseases and diabetes, with curvilinear relationships, and with beneficial effects of light to moderate drinking in people without heavy irregular drinking occasions. Biological pathways suggest an impact of heavy drinking occasions on additional diseases; however, the lack of medical epidemiological studies measuring this dimension of alcohol use precluded an in-depth analysis. For injuries, except suicide, blood alcohol concentration was the most important dimension of alcohol use. Alcohol use caused marked harm to others, which has not yet been researched sufficiently.

CONCLUSIONS

Research since 2010 confirms the importance of alcohol use as a risk factor for disease and injuries; for some health outcomes, more than one dimension of use needs to be considered. Epidemiological studies should include measurement of heavy drinking occasions in line with biological knowledge.

Does alcohol use have a causal effect on HIV incidence and disease progression? A review of the literature and a modeling strategy for quantifying the effect

In the first part of this review, the nature of the associations between alcohol use and HIV/AIDS is discussed. Alcohol use has been found to be strongly associated with incidence and progression of HIV/AIDS, but the extent to which this association is causal has traditionally remained in question. Experiments where alcohol use has been manipulated as the independent variable have since helped establish a causal effect of alcohol use on the intention to engage in condomless sex. As the intention to engage in condomless sex is a surrogate measure of actual condom use behavior, which itself is linked to HIV incidence and re-infection, the causal chain has been corroborated. Moreover, there are biological pathways between alcohol use and the course of HIV/AIDS, only in part being mediated by adherence to antiretroviral medication. In the second part of the contribution, we provide suggestions on the quantification of the link between alcohol use and HIV incidence, using risk relations derived from experimental data. The biological links between alcohol use and course of HIV/AIDS are difficult to quantify given the current state of knowledge, except for an operationalization for the link via adherence to medication based on meta-analyses. The suggested quantifications are exemplified for South Africa.