This study evaluates the impact of evening alcohol consumption on sympathetic activity and baroreflex function in binge drinkers. Our central hypothesis is that evening binge alcohol consumption will lead to sympathetic overactivity and blunted baroreflex function.

This study will recruit male and female binge drinkers who will participate in a randomized, cross-over, double-blind, placebo-based study to examine the impact of an evening of alcohol vs. placebo/fluid-control on autonomic and cardiovascular control at night and the subsequent morning. The study will utilize established techniques for assessing sleep (polysomnography) and autonomic/cardiovascular control (microneurography, beat-to-beat finger plethysmography, electrocardiogram, etc.). All subjects will undergo a familiarization night in the sleep laboratory prior to their first randomized test session with either alcohol or placebo/fluid-control. Both men and women will be tested to address a secondary aim of determining the impact of sex (male vs. female) and ovarian cycle (early follicular vs. midluteal phase) on sympathetic neural responsiveness to evening alcohol in binge drinkers. Finally, as a tertiary/exploratory aim, participants that have a respiratory disturbance index of ≥5 episodes per hour during the alcohol treatment will be asked to consider one additional overnight session where they will be randomly assigned to either continuous positive airway pressure (CPAP) or sham-CPAP for one additional night of evening alcohol consumption.

Inclusion Criteria:

• Men and women age 21 - 40 years
• Binge drinkers as defined by a pattern of consuming ≥4 drinks if female (≥5 drinks if males) in ≤ 2 hours on more than one occasion within the past 6 months, and at least once in the past 30 days. The National Institute of Alcohol Abuse and Alcoholism (NIAAA) definition of a "drink" will be used.
• Women must be eumenorrheic and premenopausal with regular and consistent menstrual cycles (i.e., ~25-30 days ovarian/uterine cycles that include 2-7 days of menstruation)
• Willingness to abstain from exercise and caffeine at least 12 hours prior to any autonomic and cardiovascular testing, and abstain from alcohol 24 hours prior to any autonomic and cardiovascular testing (unless experimentally administered).

Exclusion Criteria:

• Body mass index ≥ 35 kg/m2
• Smokers
• A physician diagnosis of diabetes
• Pregnancy
• Taking any cardiovascular medications
• Severe obstructive sleep apnea as determined by an apnea-hypopnea index of ≥ 30 episodes per hour
• Moderate-to-severe Alcohol Use Disorder (AUD) as determined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-V)
• Individuals suspected to have mutant alcohol dehydrogenase 2 (ALDH2) isoenzyme as determined using a validated flushing questionnaire
• Women using hormonal contraceptives (i.e., oral, intrauterine, etc.) in the prior 6 months

The scientific field of neural cardiovascular control in humans does not, at present, have a common data repository that would be applicable to this project. However, all data will be stored on secure University server in a de-identified manner, and investigators will make raw data available to individuals, groups, and organizations upon request and when appropriate.

On average 1 to 2 months following initial laboratory testing session

Participants were monitored for minor and serious adverse events throughout the protocol. Participants were not at risk for all-cause mortality and were not monitored for all-cause mortality. All participants were young healthy (male/female) adults and were screened for serious disorders that may predispose them towards unanticipated adverse events.