Acute ingestion of alcohol and cardiac autonomic modulation in healthy volunteers

Mapping acute alcohol effects on bodily sensations: A cross-dimensional interoceptive approach

BACKGROUND

Interoceptive processes may underlie maladaptive patterns of alcohol use. Bodily sensations experienced during alcohol intoxication could therefore reveal distinct mechanistic components relevant for addiction theory and research. Here, we apply novel tools to examine how intoxication impacts somatic awareness using bodily maps and a cardiac interoception task.

METHODS

In a double-blind, within-subjects, placebo-controlled study, social drinkers (n = 37, 17 female) were administered 0.4 g/kg of alcohol. We measured changes in self-reported bodily sensations during the ascending and descending limbs of the blood-alcohol curves using the emBODY tool. Additionally, we recorded biphasic measures of subjective alcohol effects (sedation and stimulation), changes in heart rate, and assessed psychophysical measures of cardiac beliefs using the heart rate discrimination task.

RESULTS

Acute alcohol administration altered bodily sensations, reflected by strong sensations in the chest, limbs, and head, with lesser effects in the placebo condition. Linear-mixed models examined correlates of bodily sensations across conditions. Extent of bodily sensations correlated with heart rate changes and breath alcohol content. In the ascending limb, bodily sensations negatively correlated with subjective stimulation and positively with sedation. Finally, extent of bodily sensations correlated with the metacognitive sensitivity of cardiac beliefs, suggesting a cross-dimensional integration between sensations and interoceptive awareness.

DISCUSSION

These findings highlight the value of bodily mapping in psychopharmacology, as interoceptive components of alcohol intoxication may provide a somatic basis for addiction. We interpret our results through low-sensitivity models, suggesting individuals with reduced bodily sensations during intoxication may face elevated risk for alcohol use disorder, a hypothesis that will be examined in future research.

Gastrointestinal cell injury and perceived symptoms after running the Boston Marathon

Gastrointestinal (GI) disturbances are a prevalent cause of marathon related complaints, and in extreme cases can promote life-threatening conditions such as exertional heat stroke. Our aim was to study intestinal cell injury [via intestinal fatty acid binding protein (I-FABP)] and perceived GI distress symptoms among marathon runners. We also examined potential risk factors (e.g., inadequate sleep) that could exacerbate GI disturbances in healthy, trained endurance runners. This was a parallel mixed-methods study design. 2019 Boston Marathon participants were recruited via email and subjects completed surveys before the race describing demographics and training history. Participants completed a GI questionnaire to assess presence and severity of symptoms, a survey regarding risk factors (e.g., recent illness, medications) that could promote GI disturbances, and provided a urine sample at three time points (immediately pre-race, post-race, and 24-h post-race). Due to weather, blood samples were only collected immediately and 24-h post-race. A total of 40 runners (males: n = 19, age = 44.9 ± 10.8 years; females: n = 21, age = 44.8 ± 10.6 years) completed this study. I-FABP significantly decreased from post-race (3367.5 ± 2633.5 pg/mL) to 24-h post-race (1657.3 ± 950.7 pg/mL, t (39) = -4.228, p < .001, d = -.669). There was a significant difference in overall GI symptom scores across the three time points (F (2, 39) = 41.37, p < .001). The highest average score occurred post-race (.84 ± .68), compared to pre-race (.09 ± .12) and 24-h post-race (.44 ± .28). Post-race I-FABP (r = .31, p = .048) and post-race urine specific gravity (r = .33, p = .041) were significantly correlated with post-race GI symptom scores. Our study provides further support to the individualized nature of GI disturbances, with participants experiencing a wide range of risk factors that can influence the extent of GI damage and perceived symptoms during and after exercise.

Alcohol Intake and Arterial Hypertension: Retelling of a Multifaceted Story

Alcoholic beverages are common components of diets worldwide and understanding their effects on humans' health is crucial. Because hypertension is the leading risk factor for cardiovascular diseases and all-cause mortality, the relationship of alcohol consumption with blood pressure (BP) has been the subject of extensive investigation. For the purpose of this review, we searched the terms "alcohol", "ethanol", and "arterial hypertension" on Pubmed MeSH and selected the most relevant studies. Short-term studies showed a biphasic BP response after ingestion of high doses of alcohol, and sustained alcohol consumption above 30 g/day, significantly, and dose-dependently, increased the risk for hypertension. These untoward effects of alcoholic beverages on BP can be mediated by a multiplicity of neurohormonal mechanisms. In addition to the effects on BP, excess alcohol intake might contribute to cardiac and renal hypertensive organ damage, although some studies suggest possible benefits of moderate alcohol consumption on additional cardiovascular risk factors, such as diabetes and lipoprotein(a). Some intervention studies and cumulative analyses support the evidence of a benefit of the reduction/withdrawal of alcohol consumption on BP and cardiovascular outcomes. This is why guidelines of scientific societies recommend avoidance or limitation of alcohol intake below one unit/day for women and two units/day for men. This narrative article overviews all these topics, providing an update of the current knowledge on the relationship between alcohol and BP.

The Effect of Alcohol on Blood Pressure and Hypertension

PURPOSE

To examine the acute and chronic effects of alcohol on blood pressure (BP) and the incidence of hypertension. We discuss the most current understanding of the mechanisms underlining these effects and their associations with the putative cardioprotective effects of consumption of low-to-moderate amounts of alcoholic beverages.

RECENT FINDINGS

A recent meta-analysis confirmed findings of experimental studies, demonstrating an acute biphasic effect of ethanol on BP, decreasing up to 12 h of ingestion and increasing after that. This effect is mediated by vagal inhibition and sympathetic activation. A meta-analysis found that chronic consumption of alcoholic beverages was associated with a high incidence of hypertension in men and women; it also found that, in women, the risk begins at moderate alcohol consumption. The risks of alcohol consumption are higher in Blacks than in Asians or Caucasians. The mechanism underlying the chronic effects of alcohol on BP, and particularly the differential effect on Blacks, is still unknown. Short-term trials showed that alcohol withdrawal promotes BP reduction; however, the long-term effectiveness of interventions that aim to lower BP through the restriction of alcohol consumption has not been demonstrated. The harmful effects of alcohol on BP do not support the putative cardioprotective effect of low-to-moderate consumption of alcoholic beverages. The absence of a tangible mechanism of protection, and the possibility that this beneficial effect is biased by socioeconomic and other characteristics of drinkers and abstainers, calls into question the hypothesis that consuming low amounts of alcoholic beverages improves cardiovascular health. The evidence from investigations with various designs converge regarding the acute biphasic effect of ethanol on BP and the risk of chronic consumption on the incidence of hypertension, particularly for Blacks. These effects do not support the putative cardioprotective effect of consumption of low-to-moderate amounts of alcoholic beverages. Mechanisms of chronic BP increase and the demonstration of long-term benefits of reducing alcohol intake as a means to treat hypertension remain open questions.

Evening Binge Alcohol Disrupts Cardiovagal Tone and Baroreflex Function During Polysomnographic Sleep

STUDY OBJECTIVES

Binge alcohol consumption is associated with increased cardiovascular risk. The effects of evening binge alcohol consumption (i.e., 4-5 beverages within two hours) on the vagal components of HRV and cardiovagal baroreflex sensitivity (cvBRS) during sleep remain largely equivocal. The present study examined the effects of evening binge alcohol consumption on nocturnal cardiac vagal tone and baroreflex sensitivity during stage N2, slow wave (SWS), and rapid eye movement (REM) sleep. We hypothesized that evening binge drinking would reduce HRV and cvBRS in each sleep stage.

METHODS

Following a familiarization night within the laboratory, twenty-three participants were examined following a night of binge alcohol consumption and a fluid control (randomized, crossover design). A quality nocturnal beat-to-beat blood pressure signal was obtained in both conditions in 16 participants (7 men, 9 women; 25±1 years).

RESULTS

Binge drinking reduced both the high frequency (HF) and time-domain components (i.e., pNN50 and RMSSD) of HRV in stage N2 sleep, SWS, and REM. In addition, cvBRS up-up (vagal activation) was reduced following binge alcohol consumption in stage N2 (21±3 vs. 15±3 ms/mmHg, P=0.035) and REM (15[11-28] vs. 11[9-18] ms/mmHg, P=0.009). Binge alcohol consumption reduced cvBRS down-down (vagal withdrawal) in stage N2 (23±2 vs. 14±2 ms/mmHg, P<0.001), SWS (20[14-30] vs. 14[9-17] ms/mmHg, P=0.022), and REM (14[11-24] vs. 10[7-15] ms/mmHg, P=0.006).

CONCLUSIONS

Evening binge alcohol consumption disrupts cardiac vagal tone and baroreflex function during nearly all sleep stages. These findings provide mechanistic insight into the potential role of binge drinking and alcohol abuse on cardiovascular risk.

Regression I. Experimental approaches to regression

The concept of regression is considered with an emphasis on the differences between the positions of Freud and Jung regarding its significance. The paper discusses the results of experimental analyses of individual experience dynamics (from gene expression changes and impulse neuronal activity in animals to prosocial behaviour in healthy humans at different ages, and humans in chronic pain) in those situations where regression occurs: stress, disease, learning, highly emotional states and alcohol intoxication. Common mechanisms of regression in all these situations are proposed. The mechanisms of regression can be described as reversible dedifferentiation, which is understood as a relative increase of the representation of low-differentiated (older) systems in the actualized experience. In all of the cases of dedifferentiation mentioned above, the complexity of the systemic organization of behaviour significantly decreases.

Impact of evening alcohol consumption on nocturnal autonomic and cardiovascular function in adult men and women: a dose-response laboratory investigation

STUDY OBJECTIVES

To investigate the dose-dependent impact of moderate alcohol intake on sleep-related cardiovascular (CV) function, in adult men and women.

METHODS

A total of 26 healthy adults (30-60 years; 11 women) underwent 3 nights of laboratory polysomnographic (PSG) recordings in which different doses of alcohol (low: 1 standard drink for women and 2 drinks for men; high: 3 standard drinks for women and 4 drinks for men; placebo: no alcohol) were administered in counterbalanced order before bedtime. These led to bedtime average breath alcohol levels of up to 0.02% for the low doses and around 0.05% for the high doses. Autonomic and CV function were evaluated using electrocardiography, impedance cardiography, and beat-to-beat blood pressure monitoring.

RESULTS

Presleep alcohol ingestion resulted in an overall increase in nocturnal heart rate (HR), suppressed total and high-frequency (vagal) HR variability, reduced baroreflex sensitivity, and increased sympathetic activity, with effects pronounced after high-dose alcohol ingestion (p's < 0.05); these changes followed different dose- and measure-dependent nocturnal patterns in men and women. Systolic blood pressure showed greater increases during the morning hours of the high-alcohol dose night compared to the low-alcohol dose night and placebo, in women only (p's < 0.05).

CONCLUSIONS

Acute evening alcohol consumption, even at moderate doses, has marked dose- and time-dependent effects on sleep CV regulation in adult men and women. Further studies are needed to evaluate the potential CV risk of repeated alcohol-related alterations in nighttime CV restoration in healthy individuals and in those at high risk for CV diseases, considering sex and alcohol dose and time effects.

Female drinkers are more sensitive than male drinkers to alcohol-induced heart rate increase

The present study examined the acute effect of alcohol and its cues on autonomic and cardiovascular physiology, as indexed by changes in heart rate (HR), in a relatively large sample of healthy young adult men and women. Participants (27-31 years old, final N = 145) were administered an alcoholic beverage (n = 88; 52 women) or a placebo beverage (n = 57; 35 women) in a simulated bar. Target breath alcohol concentration (BrAC) was .08 g%. HR was recorded while participants were seated alone during an initial baseline assessment in a lab room; seated with others during preparation and administration of 2 beverages in a simulated bar; and seated alone in the lab room at ascending, peak, and descending BrAC. HR increased over time for participants in both beverage groups during beverage preparation. During beverage consumption, HR decreased over time in those who drank placebo whereas HR increased over time in those who drank alcohol, increasing at a faster rate in women compared to men. HR remained elevated at the ascending, peak, and descending limb assessments only in participants who drank alcohol with HR increasing over time at ascending BrAC in the women but not men. Sex differences in HR under alcohol were not explained by sex differences in body mass index, BrAC, recent alcohol use, or subjective stimulation. Our findings suggest that women may be more sensitive to alcohol-induced increases in HR, especially in environments where alcohol cues are abundant. This may have implications for cardiovascular risks associated with alcohol. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Effect of alcohol on blood pressure

BACKGROUND

Alcohol is consumed by over 2 billion people worldwide. It is a common substance of abuse and its use can lead to more than 200 disorders including hypertension. Alcohol has both acute and chronic effects on blood pressure. This review aimed to quantify the acute effects of different doses of alcohol over time on blood pressure and heart rate in an adult population.

OBJECTIVES

Primary objective To determine short-term dose-related effects of alcohol versus placebo on systolic blood pressure and diastolic blood pressure in healthy and hypertensive adults over 18 years of age. Secondary objective To determine short-term dose-related effects of alcohol versus placebo on heart rate in healthy and hypertensive adults over 18 years of age.

SEARCH METHODS

The Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to March 2019: the Cochrane Hypertension Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 2), in the Cochrane Library; MEDLINE (from 1946); Embase (from 1974); the World Health Organization International Clinical Trials Registry Platform; and ClinicalTrials.gov. We also contacted authors of relevant articles regarding further published and unpublished work. These searches had no language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing effects of a single dose of alcohol versus placebo on blood pressure (BP) or heart rate (HR) in adults (≥ 18 years of age).

DATA COLLECTION AND ANALYSIS

Two review authors (ST and CT) independently extracted data and assessed the quality of included studies. We also contacted trial authors for missing or unclear information. Mean difference (MD) from placebo with 95% confidence interval (CI) was the outcome measure, and a fixed-effect model was used to combine effect sizes across studies.  MAIN RESULTS: We included 32 RCTs involving 767 participants. Most of the study participants were male (N = 642) and were healthy. The mean age of participants was 33 years, and mean body weight was 78 kilograms. Low-dose alcohol (< 14 g) within six hours (2 RCTs, N = 28) did not affect BP but did increase HR by 5.1 bpm (95% CI 1.9 to 8.2) (moderate-certainty evidence). Medium-dose alcohol (14 to 28 g) within six hours (10 RCTs, N = 149) decreased systolic blood pressure (SBP) by 5.6 mmHg (95% CI -8.3 to -3.0) and diastolic blood pressure (DBP) by 4.0 mmHg (95% CI -6.0 to -2.0) and increased HR by 4.6 bpm (95% CI 3.1 to 6.1) (moderate-certainty evidence for all).  Medium-dose alcohol within 7 to 12 hours (4 RCTs, N = 54) did not affect BP or HR. Medium-dose alcohol > 13 hours after consumption (4 RCTs, N = 66) did not affect BP or HR. High-dose alcohol (> 30 g) within six hours (16 RCTs, N = 418) decreased SBP by 3.5 mmHg (95% CI -6.0 to -1.0), decreased DBP by 1.9 mmHg (95% CI-3.9 to 0.04), and increased HR by 5.8 bpm (95% CI 4.0 to 7.5). The certainty of evidence was moderate for SBP and HR, and was low for DBP. High-dose alcohol within 7 to 12 hours of consumption (3 RCTs, N = 54) decreased SBP by 3.7 mmHg (95% CI -7.0 to -0.5) and DBP by 1.7 mmHg (95% CI -4.6 to 1.8) and increased HR by 6.2 bpm (95% CI 3.0 to 9.3). The certainty of evidence was moderate for SBP and HR, and low for DBP. High-dose alcohol ≥ 13 hours after consumption (4 RCTs, N = 154) increased SBP by 3.7 mmHg (95% CI 2.3 to 5.1), DBP by 2.4 mmHg (95% CI 0.2 to 4.5), and HR by 2.7 bpm (95% CI 0.8 to 4.6) (moderate-certainty evidence for all).  AUTHORS' CONCLUSIONS: High-dose alcohol has a biphasic effect on BP; it decreases BP up to 12 hours after consumption and increases BP > 13 hours after consumption. High-dose alcohol increases HR at all times up to 24 hours. Findings of this review are relevant mainly to healthy males, as only small numbers of women were included in the included trials.

Resting Heart Rate Variability: Exploring Associations With Symptom Severity in Adults With Substance Use Disorders and Posttraumatic Stress

Objective: Substance use disorders and posttraumatic stress symptoms are commonly comorbid. Previous studies have established that those with substance use disorders or posttraumatic stress disorder (PTSD) have lower high frequency-heart rate variability (HF-HRV) compared to controls, suggesting that low HF-HRV may be a biomarker of a common physiological mechanism underlying both disorders. We evaluated HF-HRV as a potential biomarker of a common underlying process by testing whether lower HF-HRV related to greater severity of substance use and PTSD symptoms in individuals with both substance use disorders and at least four symptoms of PTSD. Methods: HF-HRV was measured in 49 adults with substance use disorders and at least four symptoms of PTSD. We performed a series of regressions controlling for age to test whether low HF-HRV was associated with greater substance use disorder and PTSD symptom severity. Substance use disorder symptoms were measured by the Addiction Severity Index and PTSD symptoms were measured by the Clinician-Administered PTSD Scale and the PTSD Checklist. Results: After controlling for age, low resting HF-HRV was significantly associated with drug and alcohol symptom severity but not PTSD symptom severity. Conclusions: HF-HRV may be more sensitive to the severity of drug and alcohol use rather than PTSD. Findings may suggest that in PTSD populations, HF-HRV may primarily index comorbid substance use disorder symptoms. HF-HRV could serve as an objective measure of substance use severity and should be further investigated as a predictor of outcomes in treatment for substance use disorders.

Arterial compliance may be reduced by ingestion of red wine

The aim of this study was to assess the effect of alcohol on blood pressure and arterial compliance over 24 h in a group of volunteers, comparing the same group of subjects on two consecutive but separate days, one with alcohol intake (alcohol day) and one free of alcohol (control day). We studied 18 healthy subjects (mean age 34.2 years, range 25-53). The subjects received the two days in random order. On the alcohol day, the subjects were asked to drink two glasses of red wine (12% ethanol) between 1830 hours and 0430 hours. Measurements of heart rate, blood pressure and QKD interval (Q wave to Korotkoff (K) sound, diastolic phase (D) using Diasys Integra (Novacor, France)) were recorded (usually 1500 hours to 1500 hours). Three 'ingestion' periods were defined, from 1500 hours to 1830 hours ('before'), 1900 hours to 0430 hours ('during') and from 0430 hours to the following afternoon ('after') on both the alcohol day and on the control day. Red wine increased heart rate during alcohol ingestion and reduced arterial compliance after ingestion. The significant effect of interaction between day and ingestion period on heart rate, diastolic blood pressure and QKD were found, suggesting that the differences in response among the ingestion periods depended on whether alcohol has been consumed that day. For the first time our study indicates the effect of alcohol on 24 h arterial stiffness in a healthy group of volunteers.

Developmental differences in the effects of alcohol and stress on heart rate variability

Adolescent rats differ in their responses to stress and ethanol from their adult counterparts, although not much is known about the contribution of the autonomic nervous system (ANS) to these differences. This study assessed the impact of stress, ethanol, and their combination on parameters of heart rate variability (HRV) in adolescent and adult male Sprague-Dawley rats. Animals were habituated to the testing box and neck sensors (MouseOX, STARR Life Sciences Corp.) used for recording heart rate (HR). After 8-10min of baseline recording, animals were restrained for 90min or returned home, followed by intraperitoneal injection of 0, 0.5, 1.0, or 1.5g/kg ethanol. The 8-10min test recording occurred 30min post-injection. Ethanol-related decreases in LF (an index of sympathetic activity) were evident under non-stressed conditions in adolescents but only after stress in adults, perhaps in part due to apparent ethanol-induced sympathetic deactivation in adolescents. Parasympathetic tone, indexed by HF, was unaffected by both ethanol and stress in adolescents, while again both the 1.0 and 1.5g/kg ethanol doses decreased HF in adults following stress. Ethanol also decreased low frequency/high frequency tone (LF/HF), an index of sympathovagal balance, only in adolescents, with no decrease evident in adults. Further, stressed adults, and not adolescents, had significantly lower CORT and PROG values than their non-stressed counterparts. Taken together, these results demonstrate notable age differences in the ANS response to ethanol under stressful vs. non-stressful circumstances, reflected by ethanol-mediated autonomic effects that were more pronounced following stressor exposure in adults but under non-stressed conditions in adolescents.

Cardiac reactivity during the ascending phase of acute intravenous alcohol exposure and association with subjective perceptions of intoxication in social drinkers

BACKGROUND

The aim of this study was to characterize cardiac reactivity measures, heart rate (HR), and heart rate variability (HRV), following acute intravenous (IV) alcohol administration and their association with subjective responses in social drinkers.

METHODS

Twenty-four subjects (11 females) received IV alcohol infusions to attain and clamp the breath alcohol concentration (BrAC) at 50 mg% or placebo in separate sessions. Serial 5-minute cardiac recordings at baseline and during the infusion were analyzed to obtain frequency and time domain cardiac measures. Self-reported subjective perceptions were also obtained at the same time points.

RESULTS

HR showed significant decreases from baseline, while the HRV measure pNN50 showed steady increases during the ascending phase of alcohol infusion. HR was inversely correlated with pNN50 across time and treatment. There was a significant association of HR with subjective feelings of high, intoxication, feeling drug effects, and liking drug effects across time during the ascending phase.

CONCLUSIONS

Acute IV alcohol resulted in decreases in HR and increases in HRV consistent with autonomic parasympathetic activation. The association of these changes with subjective responses suggests that cardiac reactivity may serve as a physiological marker of subjective alcohol effects. This study broadens the understanding of acute cardiovascular effects of alcohol and clinically significant cardiac conditions such as arrhythmia and cardiomyopathy associated with chronic alcohol drinking.

Cardiac autonomic modulation during methadone therapy among heroin users: a pilot study

BACKGROUND

Methadone therapy benefits heroin users in both the medical and psychosocial dimensions. However, both heroin and methadone have cardiac toxicity. Only limited information is available describing the changes in cardiac autonomic function of heroin users and effects of methadone therapy. We conduct the current study to explore the cardiac vagal function in heroin users as well as the impact of lapse and methadone therapy.

METHODS

80 heroin users from a methadone therapy clinic were distributed into 31 compliant and 49 incompliant patients according to whether they lapsed into heroin use within 10 days. 40 healthy control subjects were recruited from the community. Participants underwent electrocardiographic recordings and the heroin users were further investigated before and after methadone therapy. Spectral analysis of heart rate variability (HRV) was computed for cardiac parasympathetic modulation (high-frequency power, HF) and cardiac sympathetic modulation (normalized low-frequency power, LF%).

RESULTS

The baseline HRV parameters found lower HF values for heroin users and lower RR interval values for patients with a recent lapse compared with the healthy control subjects. After 1h of methadone administration, heroin users who had lapsed showed a significant increase in HF but the heroin users who had not lapsed did not.

CONCLUSION

Our findings suggest that heroin users show decreased cardiac vagal activity and that methadone therapy immediately facilitates vagal regulation in patients with a recent lapse. The differential patterns of autonomic alteration under methadone between those with and without lapse might offer an objective measure of lapse.

Third-degree atrioventricular block in an adolescent following acute alcohol intoxication

Alcohol abuse is a major problem among adolescents, and has both acute, potentially lethal, and long-term harmful effects. The authors describe an adolescent who was in a subcomatose condition after binge drinking. His serum alcohol concentration was 3.7 g/l. The next morning, before transfer to the paediatric ward, he developed a third-degree atrioventricular (AV) block without cardiac output while his infusion needle was removed. This recovered spontaneously after a precordial thump. Retrospectively, electrocardiography showed an increasing PR prolongation (200-300 ms) before the removal of the infusion needle. ECG recordings several hours later showed a first-degree AV block, which was no longer seen during follow-up, 1 month later. The authors conclude that acute alcohol poisoning has the potential to prolong the PR interval in young, healthy adolescents without pre-existing first-degree AV block and provoke a third-degree AV block after vagal stimulation. It is yet another potential danger of acute alcohol intoxication in this age group.