0091 Influence of Evening Alcohol Intake on Nocturnal Heart Rate

Abstract Introduction Binge alcohol consumption has detrimental effects on cardiovascular health and sleep. The simultaneous influence on sleep and cardiovascular measures may lead to an adverse nocturnal cardiac profile. The aim of the present study was to examine the impact of evening alcohol consumption on nocturnal heart rate (HR) patterns. We hypothesized that alcohol intake would result in a sustained increase in HR throughout the night and reduced HR dipping relative to pre-sleep wakefulness. Methods In a randomized crossover design, ten participants (5 male, 5 female; 26±2 yrs; 28±1 kg/m2) underwent a night of binge alcohol consumption and a fluid control separated by one month. Sleep and nocturnal HR were measured using continuous overnight polysomnography and electrocardiogram. HR was averaged across 15-minute intervals over the 8-hour sleep period. Results Consistent with our initial hypothesis, a condition effect was observed whereby average raw HR was increased following alcohol consumption (Fluid Control: 60±3 vs. Alcohol: 66±3 beats/min, p=0.003). This condition effect was absent when examining average change in HR relative to a 15-minute wakefulness period (Fluid Control: ∆-2.3±0.6 vs. Alcohol: ∆-2.7±1.1 beats/min change, p=0.75). A condition x time effect was present in both average raw HR (p=0.003) and relative HR change from wakefulness (p=0.01). Contrary to our hypothesis, post hoc analyses revealed that the alcohol condition demonstrated augmented relative HR dipping 15 (Fluid Control: ∆-3.2±0.6 vs. Alcohol: ∆-4.8±0.8 beats/min) and 30 minutes (Fluid Control: ∆-3.1±1.1 vs. Alcohol: ∆-6.0±1.0 beats/min) after lights out. However, a substantial increase in relative HR was observed in the alcohol condition when compared to the control 210 (Fluid Control: ∆-3.1±0.8 vs. Alcohol: ∆1.1±1.0 beats/min) and 225 minutes (Fluid Control: ∆-3.6±0.6 vs. Alcohol: ∆1.6±1.5 beats/min) after lights out. Conclusion Evening binge alcohol consumption increased HR throughout the sleep period. The overnight profile demonstrated that alcohol elicited a steeper decline in nocturnal HR immediately after lights out, but a significant augmentation of HR during the later portion of the night. The observed elevation in overall HR and further relative increase in the second half of the night may contribute to cardiovascular risk following alcohol intake. Support (if any) NIH (AA-024892; U54GM115371; P20GM103474).