Circadian regulation of breath alcohol concentration

Disruption of circadian rhythms promotes alcohol use: a systematic review

This systematic review investigates the bidirectional relationship between alcohol consumption and disrupted circadian rhythms. The goal of this study was to identify (i) the types of circadian rhythm disruptors (i.e. social jet lag, extreme chronotypes, and night shift work) associated with altered alcohol use and (ii) whether sex differences in the consequences of circadian disruption exist. We conducted a search of PubMed, Embase, and PsycINFO exclusively on human research. We identified 177 articles that met the inclusion criteria. Our analyses revealed that social jet lag and the extreme chronotype referred to as eveningness were consistently associated with increased alcohol consumption. Relationships between night shift work and alcohol consumption were variable; half of articles reported no effect of night shift work on alcohol consumption. Both sexes were included as participants in the majority of the chronotype and social jet lag papers, with no sex difference apparent in alcohol consumption. The night shift research, however, contained fewer studies that included both sexes. Not all forms of circadian disruption are associated with comparable patterns of alcohol use. The most at-risk individuals for increased alcohol consumption are those with social jet lag or those of an eveningness chronotype. Direct testing of the associations in this review should be conducted to evaluate the relationships among circadian disruption, alcohol intake, and sex differences to provide insight into temporal risk factors associated with development of alcohol use disorder.

Sleep and circadian influences on blood alcohol concentration

STUDY OBJECTIVES

Anecdotally, adults reach higher levels of subjective intoxication on days they are fatigued or sleep-deprived, but sleep is not typically discussed as a predictor of blood alcohol concentration (BAC) in clinical settings. To inform clinical work and future research, this perspective reviews data examining the impact of sleep (process S) and circadian (process C) factors on indicators of BAC in humans and animal models.

METHODS

Literature searches of medical and psychological databases were conducted to identify articles that manipulated sleep/circadian factors and reported effects on indicators of alcohol pharmacology (e.g. BAC, alcohol metabolism).

RESULTS

Of the 86 full-text articles reviewed, 21 met inclusion criteria. Studies included manipulations of time of day, circadian phase (evidence for process C), and time in bed (evidence for process S). Evidence for time-of-day effects on alcohol pharmacology was most compelling. Studies also provided evidence for circadian phase effects, but failed to find support for time-in-bed effects. Although results were not uniform across studies, most evidence from human and animal models indicates that peak BACs occur toward the beginning of the biological day, with some studies indicating slower alcohol elimination rates at this time.

CONCLUSIONS

Circadian factors likely influence alcohol pharmacokinetics, perhaps due to altered elimination of alcohol from the body. This means that individuals may reach higher BACs if they drink during the morning (when, for most people, circadian alerting is low) versus other times of the day. Alcohol prevention and intervention efforts should highlight sleep/circadian health as a potential contributor to alcohol-related harm.

Breath Alcohol Test Results in Equine Veterinarians after Performing an Abdominal Ultrasound with Ethanol

Transcutaneous abdominal ultrasonography using alcohol saturation is used in the diagnostic workup of a variety of conditions in horses. The duration of the examination and the amount of alcohol used in each case may vary depending on several factors. The aim of this study is to describe the breath alcohol test results obtained by veterinarians performing abdominal ultrasound on horses. Six volunteers were enrolled, after written consent, and a Standardbred mare was used for the whole study protocol. Each operator performed a total of 6 ultrasounds by pouring the ethanol solution from a jar or by spray application, for a duration of 10, 30, and 60 min. An infrared breath alcohol analyzer was used immediately after completing the ultrasonography and at 5-min intervals until a negative result was obtained. Positive results were obtained for 0–60 min after the procedure. A statistically significant difference was found between the groups that used more than 1000 mL, 300–1000 mL, and less than 300 mL of ethanol. No significant differences were observed between the type of ethanol administration and the time of exposure. Based on this study, equine vets who perform ultrasound on horses can test positive at the breath alcohol test for up to 60 min following ethanol exposure.