First pass metabolism of ethanol is strikingly influenced by the speed of gastric emptying

Alcohol associated liver disease and bariatric surgery: Current perspectives and future directions

Bariatric surgery is a routinely performed procedure and is associated with a reduction in all-cause mortality in patients with obesity. However, bariatric surgery has also been linked to increased alcohol use with up to 30% of these patients developing alcohol use disorder (AUD). The mechanism of AUD after bariatric surgery is multifactorial and includes anatomic, metabolic, and neurohumoral changes associated with post-surgical anatomy. These patients are at increased risk of alcohol associated liver disease and, in some cases, require liver transplantation. In this article, we provide a scoping review of epidemiology, pathophysiology, and clinical outcomes of alcohol-related health conditions after bariatric surgery.

Pharmacokinetic Analysis of Ethanol in a Human Study: New Modification of Mathematic Model

In the pharmacokinetic analysis of ethanol after oral administration, only single- or two-compartment models are used, but their precision in estimating pharmacokinetic parameters might be insufficient. In a recent study, pharmacokinetic analysis using a modified Norberg three-compartment model was performed after oral administration of differently sweetened alcoholic solutions and compared to pharmacokinetic analysis using the classic Widmark model. On three occasions, eight male volunteers consumed differently sweetened alcoholic solutions: non-sweetened, sweetened with sucrose, and sweetened with steviol glycoside. Blood ethanol concentration was determined from samples obtained at t = 15, 30, 60, 90, 120, 180 min after consumption. Pharmacokinetic analysis was performed model independently, using the classic Widmarks model and using the modified Norberg model. Results showed that estimated pharmacokinetic parameters depend on the type of model used. The classic Widmark model in particular overestimated the fraction of absorbed ethanol from the gastrointestinal system to systemic circulation. Furthermore, the type of sweetener also affected pharmacokinetic parameters, although the difference was not statistically significant. In conclusion, the novel pharmacokinetic model, while being more physiological, fits experimental data better and hence is more suitable for modelling real-life alcohol consumption. In addition, the effect of natural non-caloric sweetener steviol glycoside on ethanol pharmacokinetics, analysed for the first time in the current research, might be different when compared to the common-used sweetener sucrose.

The Self-Rated Effects of Alcohol Are Related to Presystemic Metabolism of Alcohol

AIMS

A high number of alcohol units required to feel a subjective effect of alcohol predicts future alcohol use disorders (AUDs). The subjective response to alcohol can be measured using the validated retrospective self-rated effects of alcohol (SRE) questionnaire. Few studies have investigated the specific relationship between SRE and blood alcohol concentration (BAC) in an experimental setting.

METHODS

Twenty healthy young adult male volunteers who had experience with binge drinking, but did not have AUD, filled out the SRE-questionnaire and were served with a fixed amount of alcohol per body weight. BACs were measured throughout a 12-hour period, reaching a maximum BAC of ~0.13%. Median split of SRE-scores was utilized to compare BACs among participants with relatively high effects (low SRE) and relatively low effects (high SRE) of alcohol.

RESULTS

Participants reporting a relatively low SRE-score had a statistically significant higher measured BAC at all time points until alcohol was eliminated. This was especially pronounced during the first 2 hours after alcohol (P = 0.015) without a significant difference in the alcohol elimination rate being detected.

CONCLUSION

The study indicates that a self-ated SRE-score is related to BACs after the ingestion of a standardized amount of alcohol per body weight. Reporting a higher number of alcohol units before feeling an effect was related to a lower BAC. As the differences in BAC between relatively high and low self-rated effects appeared rapidly after intake, this could be interpreted as an effect of presystemic metabolism of alcohol.

Slow Drinking of Beer Attenuates Subjective Sedative Feeling in Healthy Volunteers: A Randomized Crossover Pilot Study

The change in physiological parameters and subjective feelings according to the speed of drinking alcohol has not been reported to date. The aim of this randomized crossover pilot study was to investigate the objective and subjective effects of different speeds of alcohol ingestion in healthy volunteers. Accordingly, 11 male and 7 female healthy Japanese adults were asked to consume 480 mL of beer at three different drinking speeds (80, 40, and 20 mL/5 min). According to the objective measurement, the transient increase in blood alcohol and serum uric acid concentrations was most inhibited at a drinking speed of 20 mL/5 min. Acetate, lactate, pyruvate, and lactate/pyruvate ratios did not differ between the three drinking speeds. Stimulant feelings measured by the subjective scores of the Brief Biphasic Alcohol Effects Scale did not differ between the three speeds. However, the sedative feeling score obtained at a drinking speed of 20 mL/5 min (the slowest speed of alcohol consumption) was significantly weakened in comparison with those obtained at drinking speeds of 40 and 80 mL/5 min. Therefore, a slower consumption of alcohol mitigated the subjective sedative feeling. The effects of slower alcohol consumption may be caused by the slower slope of the increasing trend of blood alcohol concentration.

Lower Strength Alcohol Products-A Realist Review-Based Road Map for European Policy Making

This paper reports the result of a realist review based on a theory of change that substitution of higher strength alcohol products with lower strength alcohol products leads to decreases in overall levels of alcohol consumption in populations and consumer groups. The paper summarizes the results of 128 publications across twelve different themes. European consumers are increasingly buying and drinking lower strength alcohol products over time, with some two fifths doing so to drink less alcohol. It tends to be younger more socially advantaged men, and existing heavier buyers and drinkers of alcohol, who take up lower strength alcohol products. Substitution leads to a lower number of grams of alcohol bought and drunk. Although based on limited studies, buying and drinking lower strength products do not appear to act as gateways to buying and drinking higher strength products. Producer companies are increasing the availability of lower strength alcohol products, particularly for beer, with extra costs of production offset by income from sales. Lower strength alcohol products tend to be marketed as compliments to, rather than substitutes of, existing alcohol consumption, with, to date, the impact of such marketing not evaluated. Production of lower strength alcohol products could impair the impact of existing alcohol policy through alibi marketing (using the brand of lower strength products to promote higher strength products), broadened normalization of drinking cultures, and pressure to weaken policies. In addition to increasing the availability of lower strength products and improved labelling, the key policy that favours substitution of higher strength alcohol products with lower strength products is an alcohol tax based on the dose of alcohol across all products.

Comparative effects of low-carbohydrate, full-strength and low-alcohol beer on gastric emptying, alcohol absorption, glycaemia and insulinaemia in health

AIMS

The aim of this study was to evaluate the comparative effects of low-carbohydrate (LC), full-strength (FS), and low-alcohol (LA) beer on gastric emptying (GE), ethanol absorption, glycaemia and insulinaemia in health.

METHODS

Eight subjects (four male, four female; age: 20.4 ± 0.4 years; BMI 22.7 ± 0.4 kg/m² ) had concurrent measurements of GE, plasma ethanol, blood glucose and plasma insulin for 180 min on three separate occasions after ingesting 600 mL of (i) FS beer (5.0% w/v, 246 kcal, 19.2 g carbohydrate), (ii) LC beer (4.6% w/v, 180 kcal, 5.4 g carbohydrate) and (iii) LA beer (2.6% w/v, 162 kcal, 17.4 g carbohydrate) labelled with 20 MBq 99mTc-calcium phytate, in random order.

RESULTS

There was no difference in the gastric 50% emptying time (T50) (FS: 89.0 ± 13.5 min vs LC: 79.5 ± 12.9 min vs LA: 74.6 ± 12.4 min; P = .39). Plasma ethanol was less after LA than LC (P < .001) and FS (P < .001), with no difference between LC and FS (P = 1.0). There was an inverse relationship between plasma ethanol at 15 min and GE after LA (r = -0.87, P < .01) and a trend for inverse relationships after LC (r = -0.67, P = .07) and FS (r = -0.69, P = .06). The AUC 0-180 min for blood glucose was greater for LA than LC (P < .001), with no difference between LA and FS (P = .40) or LC and FS (P = 1.0).

CONCLUSION

In healthy young subjects, GE of FS, LC and LA beer is comparable and a determinant of the plasma ethanol response.

Comparison of Gastric Emptying Time after the Ingestion of Whisky with Isocalorically Adjusted Glucose Solution

Previous studies have shown that the liquid gastric emptying mainly depended on energy content, regardless of compositional differences. But the gastric emptying of alcoholic beverages remains unclear. Therefore, we performed the present study to compare gastric emptying times between whisky mixed with water and glucose solution with uniform energy contents and volumes. As a crossover study, 10 healthy male volunteers ingested one of 3 test solutions with a uniform volume of 150 ml, i.e., whisky with water-containing whisky 30 ml (67 kcal), sugar water containing glucose 16.8 g (67 kcal), and water (0 kcal), and the gastric emptying time of each beverage was then assessed by ultrasound measurements of the gastric antral cross-sectional area. The gastric emptying pattern of whisky with water was faster than that of isocaloric sugar water, but slower than that of water. Each antral cross-sectional area 20, 30, and 40 min after the ingestion of sugar water was significantly larger than that of whisky with water. Antral cross-sectional areas 10 and 20 min after the ingestion of water were significantly smaller than those of whisky with water. In conclusion, the gastric emptying time of whisky would be faster than that of isocaloric glucose solution and slower than that of water. Unlike the other beverages, the gastric emptying time of alcohol drinks does not purely depend on the energy content because alcohol itself has no calorie before absorption. This study is registered with the University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN000034443).

Development of a Physiologically Based Pharmacokinetic Model for Prediction of Ethanol Concentration-Time Profile in Different Organs

AIMS

A physiologically based pharmacokinetic (PBPK) modeling approach was used to simulate the concentration-time profile of ethanol (EtOH) in stomach, duodenum, plasma and other tissues upon consumption of beer and whiskey under fasted and fed conditions.

METHODS

A full PBPK model was developed for EtOH using the advanced dissolution, absorption and metabolism (ADAM) model fully integrated into the Simcyp Simulator® 15 (Simcyp Ltd., Sheffield, UK). The prediction performance of the developed model was verified and the EtOH concentration-time profile in different organs was predicted.

RESULTS

Simcyp simulation showed ≤ 2-fold difference in values of EtOH area under the concentration-time curve (AUC) in stomach and duodenum as compared to the observed values. Moreover, the simulated EtOH maximum concentration (Cmax), time to reach Cmax (Tmax) and AUC in plasma were comparable to the observed values. We showed that liver is exposed to the highest EtOH concentration, faster than other organs (Cmax = 839.50 mg/L and Tmax = 0.53 h), while brain exposure of EtOH (AUC = 1139.43 mg·h/L) is the highest among all other organs. Sensitivity analyses (SAs) showed direct proportion of EtOH rate and extent of absorption with administered EtOH dose and inverse relationship with gastric emptying time (GE) and steady-state volume of distribution (Vss).

CONCLUSIONS

The current PBPK model approach might help with designing in vitro experiments in the area of alcohol organ damage or alcohol-drug interaction studies.

Comparison of ethanol concentrations after drinking in patients who underwent total gastrectomy versus healthy controls

BACKGROUND

The safety of drinking in patients who have undergone total gastrectomy for gastric cancer has not been established. We conducted a clinical trial to investigate the trend in alcohol absorption in actual patients.

METHODS

Patients who received total gastrectomy with lymph-node dissection and Roux-en-Y reconstruction six or more months ago were enrolled. Participants drank 1 unit (20 g) of ethanol within 1 h starting at least 1 h after a meal. The blood alcohol concentration (BAC) was then estimated by a measurement of the breath alcohol concentration. The peak and trend in the BAC in patients was compared with that in healthy volunteers who were matched with patients for the alcohol-sensitive genotype.

RESULTS

Ten patients and 10 healthy people were enrolled in the BAC evaluation. The peak BAC (%) was 0.158 in patients after total gastrectomy versus 0.110 in control (P < 0.001). The mean half-life of BAC was 58.0 min in the patient group and 94.0 min in the control group, although the mean time to complete drinking was significantly longer in the patient group than in the control group at 40.8 versus 21.9 min (P = 0.009).

CONCLUSION

Drinking alcohol is likely to carry a risk of increasing the BAC in patients who have undergone total gastrectomy.

Natural Recovery by the Liver and Other Organs after Chronic Alcohol Use

Chronic, heavy alcohol consumption disrupts normal organ function and causes structural damage in virtually every tissue of the body. Current diagnostic terminology states that a person who drinks alcohol excessively has alcohol use disorder. The liver is especially susceptible to alcohol-induced damage. This review summarizes and describes the effects of chronic alcohol use not only on the liver, but also on other selected organs and systems affected by continual heavy drinking—including the gastrointestinal tract, pancreas, heart, and bone. Most significantly, the recovery process after cessation of alcohol consumption (abstinence) is explored. Depending on the organ and whether there is relapse, functional recovery is possible. Even after years of heavy alcohol use, the liver has a remarkable regenerative capacity and, following alcohol removal, can recover a significant portion of its original mass and function. Other organs show recovery after abstinence as well. Data on studies of both heavy alcohol use among humans and animal models of chronic ethanol feeding are discussed. This review describes how (or whether) each organ/tissue metabolizes ethanol, as metabolism influences the organ’s degree of injury. Damage sustained by the organ/tissue is reviewed, and evidence for recovery during abstinence is presented.

Effects of stomach content on the breath alcohol concentration-transdermal alcohol concentration relationship

INTRODUCTION

Wearable devices that obtain transdermal alcohol concentration (TAC) could become valuable research tools for monitoring alcohol consumption levels in naturalistic environments if the TAC they produce could be converted into quantitatively-meaningful estimates of breath alcohol concentration (eBrAC). Our team has developed mathematical models to produce eBrAC from TAC, but it is not yet clear how a variety of factors affect the accuracy of the models. Stomach content is one factor that is known to affect breath alcohol concentration (BrAC), but its effect on the BrAC-TAC relationship has not yet been studied.

METHODS

We examine the BrAC-TAC relationship by having two investigators participate in four laboratory drinking sessions with varied stomach content conditions: (i) no meal, (ii) half and (iii) full meal before drinking, and (iv) full meal after drinking. BrAC and TAC were obtained every 10 min over the BrAC curve.

RESULTS

Eating before drinking lowered BrAC and TAC levels, with greater variability in TAC across person-device pairings, but the BrAC-TAC relationship was not consistently altered by stomach content. The mathematical model calibration parameters, fit indices, and eBrAC curves and summary score outputs did not consistently vary based on stomach content, indicating that our models were able to produce eBrAC from TAC with similar accuracy despite variations in the shape and magnitude of the BrAC curves under different conditions.

DISCUSSION AND CONCLUSIONS

This study represents the first examination of how stomach content affects our ability to model estimates of BrAC from TAC and indicates it is not a major factor.

The History of Alcoholic Liver Disease: From an Unrecognized Disease to One of the Most Frequent Diseases in Hepatology

This review describes the history of alcoholic liver disease from the beginning of the 1950s until now. It details how the hepatotoxicity of alcohol was discovered by epidemiology and basic research primarily by using new feeding techniques in rodents and primates. The article also recognizes the pioneering work of scientists who contributed to the understanding of the pathophysiology of alcoholic liver disease. In addition, clinical aspects, such as the development of diagnostics and treatment options for alcoholic liver disease, are discussed. Up-to-date knowledge of the mechanism of the disease in 2020 is presented.

Translational dynamics of alcohol tolerance of preclinical models and human laboratory studies

Increasing sensitivity due to alcohol intake has been explored using molecular and cellular mechanisms of sensitization and adaptive biobehavioral changes as well as through negative experiences of altered function during withdrawal. However, within both a preclinical and human laboratory setting, little has been elucidated toward understanding the neural substrates of decreased sensitivity to alcohol effects, that is, alcohol tolerance. More paradigms assessing alcohol tolerance are needed. Tolerance can be assessed through both self-reported response (subjective) and observed (objective) measurements. Therefore, sensitivity to alcohol is an exploitable variable that can be utilized to disentangle the diverse alcohol use disorder (AUD) phenotypical profile. This literature review focuses on preclinical models and human laboratory studies to evaluate alcohol tolerance and its modulating factors. Increased understanding of alcohol tolerance has the potential to reduce gaps between preclinical models and human laboratory studies to better evaluate the development of alcohol-related biobehavioral responses. Furthermore, alcohol tolerance can be used as an AUD phenotypic variable in randomized clinical trials designed for developing AUD therapies. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Body mass index modifies the association between frequency of alcohol consumption and incidence of hypertension in men but not in women: a retrospective cohort study

Alcohol consumption is one of the major modifiable risk factors of hypertension. The aim of the present retrospective study was to assess the clinical impact of obesity on the association between alcohol consumption and the incidence of hypertension. The present study included 5116 male and 6077 female university employees with a median age of 32 (interquartile range 27-39) who underwent annual health checkups between January 2005 and March 2013. Self-reported drinking frequency was recorded at their first checkup and categorized into rarely and 1-3, 4-6, and 7 days/week. During the median observational period of 4.9 years (interquartile range 2.1-8.3), hypertension, defined as systolic/diastolic blood pressure of ≥140/90 mmHg and/or self-reported treatment for hypertension, was observed in 1067 (20.9%) men and 384 (6.3%) women. Poisson regression models adjusted for clinically relevant factors revealed a dose-dependent association between drinking frequency and the incidence of hypertension in men (adjusted incidence rate ratio [95% confidence interval] of men who drank rarely, 1-3, 4-6, and 7 days/week was 1.00 [reference], 1.12 [0.97-1.30], 1.42 [1.19-1.70], and 1.35 [1.14-1.59], respectively; P_trend < 0.001). However, this association was not observed in women. The dose-dependent association was significant in nonobese men (body mass index (BMI) < 25 kg/m²), but not in obese men (BMI ≥25 kg/m²) (P for interaction between drinking frequency and BMI = 0.072). The present study provides clinically useful evidence to identify the drinkers who may reap the health benefits of abstinence from alcohol consumption.

Effect of a Snack Bar Optimized to Reduce Alcohol Bioavailability: A Randomized Controlled Clinical Trial in Healthy Individuals

Alcohol intoxication impairs judgment and reaction times and the level of blood alcohol concentration (BAC) is highly correlated with accidents and injury. We hypothesized that a food optimized to delay gastric emptying, a reduced alcohol bioavailability bar (RABB), would decrease postprandial BAC and alcohol bioavailability with greater caloric-efficiency than control foods. Therefore, we evaluated the RABB in a randomized, crossover trial in 21 overnight fasted healthy adults (10 male, 11 female). Just before consuming a moderate dose of alcohol (0.3-0.35 g/kg body weight), participants ate either (1) no food (NF, 0 kcal), (2) the RABB (210 kcal), (3) a savory snack mix (SSM, 210 kcal), or (4) a multicomponent meal (MCM, 635 kcal) and their BAC was measured over 90 minutes using a breathalyzer, the primary endpoint being peak BAC (pBAC). pBACs were analyzed by repeated measures analysis of variance (ANOVA) (F = 107.5, P < .0001) with the differences between means assessed using Tukey's honestly significant difference test. The pBAC of each group was different (P < .001) from all other groups (NF = 0.064 ± 0.003, SSM = 0.047 ± 0.002, RABB = 0.031 ± 0.002, MCM = 0.020 ± 0.002%; mean ± standard error of the mean). Furthermore, the bioavailability of alcohol over 90 minutes (BA90) was reduced compared to the NF group by similar margins (SSM = 22.0 ± 2.2, RABB = 45.0 ± 3.8, MCM = 67.9 ± 3.1%) with the mean BA90 of each group different from all other groups (P < .001). Compared to the NF condition, the average reduction of pBAC per 100 calories of food consumed was higher for the RABB (24.0%) than either the SSM (11.8%) or the MCM (10.7%). This study demonstrates that the RABB can reduce both pBAC and alcohol bioavailability with high caloric-efficiency.

Tobacco smoke and ethanol during adolescence: Both combined- and single-drug exposures lead to short- and long-term disruption of the serotonergic system in the mouse brain

The impairment of the serotonergic system contributes to nicotine and ethanol effects on mood, suggesting that this system is targeted by each of these drugs and that co-exposure possibly worsens the disruption. Here, we tested this hypothesis in an adolescent mice model of tobacco smoke and/or ethanol exposure. From postnatal day (PN) 30-45, Swiss mice were exposed to one of the following: 1) tobacco smoke (SMK; research cigarettes 2R1F, whole-body exposure, 8 h/daily); 2) ethanol (ETOH; 2 g/kg i.p., every other day); 3) SMK + ETOH; 4) Control (VEH). At PN45 (end-of-exposure), hippocampal serotonin transporter (5 H TT) binding was increased in SMK and decreased in ETOH male mice. At PN50 (short-term deprivation), cortical 5 H TT was reduced in all drug-exposed mice. In the hippocampus, similar deficits were identified in females. In both brain regions, the effects of SMK + ETOH deprivation on 5 H TT were equivalent to the damage caused by either drug. At PN50, hippocampal 5 H T1A receptor binding was reduced in ETOH and SMK + ETOH mice. Similar results were observed in the male cortex. In females, deficits were identified in SMK mice. In both brain regions, SMK + ETOH 5 H T1A deficits reflected the summation of SMK and ETOH outcomes. At PN75 (long-term deprivation), there was a late-emergent increase in cortical 5 H T1A binding in SMK mice, while cortical 5 H T2 receptor binding was similarly increased in SMK and SMK + ETOH groups. Adolescent SMK and/or ETOH serotonergic impairment is sex-dependent and most evident during short-term deprivation. SMK + ETOH deprivation evokes serotonergic disruption that is at least equivalent to that caused by either drug alone.

Alcohol intake, ADH1B and ADH1C genotypes, and the risk of colorectal cancer by sex and subsite in the Netherlands Cohort Study

The alcohol-colorectal cancer (CRC) association may differ by sex and ADH1B and ADH1C genotypes. ADH enzymes oxidize ethanol to acetaldehyde, both of which are human carcinogens. The Netherlands Cohort Study includes 120 852 participants, aged 55-69 years at baseline (1986), and has 20.3 years follow-up (case-cohort: nsubcohort = 4774; ncases = 4597). The baseline questionnaire included questions on alcohol intake at baseline and 5 years before. Using toenail DNA, available for ~75% of the cohort, we successfully genotyped six ADH1B and six ADH1C SNPs (nsubcohort = 3897; ncases = 3558). Sex- and subsite-specific Cox hazard ratios and 95% confidence intervals for CRC were estimated comparing alcohol categories, genotypes within drinkers and alcohol categories within genotype strata. We used a dominant genetic model and adjusted for multiple testing. Alcohol intake increased CRC risk in both sexes, though in women only in the (proximal) colon when in excess of 30 g/day. In male drinkers, ADH1B rs4147536 increased (distal) colon cancer risk. In female drinkers, ADH1C rs283415 increased proximal colon cancer risk. ADH1B rs3811802 and ADH1C rs4147542 decreased CRC risk in heavy (>30 g/day) and stable drinkers (compared to 5 years before baseline), respectively. Rs3811802 and rs4147542 significantly modified the alcohol-colon cancer association in women (Pfor interaction = 0.004 and 0.02, respectively). A difference in associations between genotype strata was generally clearer in men than women. In conclusion, men showed increased CRC risks across subsites and alcohol intake levels, while only colon cancer risk was increased in women at heavy intake levels. ADH1B rs3811802 and ADH1C rs4147542 significantly modified the alcohol-colon cancer association in women.

Beer effects on postprandial digestive symptoms and gastroesophagic physiology

BACKGROUND

Beer has been related to gastroesophageal reflux (GER) and dyspepsia, based on its alcohol and gas content. The aim of this study is to evaluate the association between moderate consumption of traditional and alcohol-free beer and upper digestive symptoms, gastric accommodation and GER.

METHODS

Healthy adults without frequent gastrointestinal symptoms and GER disease were included. The intervention involved administration of traditional beer to 10 subjects (substudy 1) and alcohol-free beer to 20 (substudy 2); control intervention entailed administration of water. Study duration was 2 weeks (control/intervention). Postprandial gastric accommodation was assessed through the maximum tolerated volume during a nutrient drink test after the ingestion of water (day 1) and beer (day 8), in which symptoms of dyspepsia were evaluated every 5 minutes. An impedance-pH monitoring assessed 24 hours and post-NDT GER (days 1 and 8). Symptoms were evaluated daily during the study. The defined variables were compared between visits and weeks using a nonparametric test for paired data.

KEY RESULTS

Dyspepsia symptoms showed a progressive increase during the NDT for both interventions in the 2 substudies, though no significant differences were detected in the MTV analysis. No differences were detected in the sum of weekly symptoms. The analysis of impedance-pH monitoring did not show any differences between intervention and control visits for both interventions.

CONCLUSIONS AND INFERENCES

Moderate consumption of traditional and alcohol-free beer does not increase dyspeptic symptoms or GER in healthy subjects, whether in a controlled-intake or real-life situation. Neither gastric accommodation nor reflux episodes are modified in this context.

Cardiovascular and Cutaneous Responses to the Combination of Alcohol and Soft Drinks: The Way to Orthostatic Intolerance?

Aim: Acute ingestion of alcohol is often accompanied by cardiovascular dysregulation, malaise and even syncope. The full hemodynamic and cutaneous responses to the combination of alcohol and sugar (i.e., alcopops), a common combination in young people, and the mechanisms for the propensity to orthostatic intolerance are not well established. Thus, the purpose of this study was to evaluate the cardiovascular and cutaneous responses to alcopops in young subjects. Methods: Cardiovascular and cutaneous responses were assessed in 24 healthy young subjects (12 men, 12 women) sitting comfortably and during prolonged active standing with a 30-min baseline and 130 min following ingestion of 400 mL of either: water, water + 48 g sugar, water + vodka (1.28 mL.kg^-1 of body weight, providing 0.4 g alcohol.kg^-1), water + sugar + vodka, according to a randomized cross-over design. Results: Compared to alcohol alone, vodka + sugar induced a lower breath alcohol concentration (BrAC), blood pressure and total peripheral resistance (p < 0.05), a higher cardiac output and heart rate (p < 0.05) both in sitting position and during active standing. In sitting position vodka + sugar consumption also led to a greater increase in skin blood flow and hand temperature (p < 0.05) and a decrease in baroreflex sensitivity (p < 0.05). We observed similar results between men and women both in sitting position and during active standing. Conclusion: Despite lower BrAC, ingestion of alcopops induced acute vasodilation and hypotension in sitting position and an encroach of the hemodynamic reserve during active standing. Even if subjects did not feel any signs of syncope these results could be of clinical importance with higher doses of alcohol or if combined to other hypotensive challenges.

Effect of 8-weeks prebiotics/probiotics supplementation on alcohol metabolism and blood biomarkers of healthy adults: a pilot study

PURPOSE

Modulating gut bacteria via regular prebiotics/probiotics consumption may improve the metabolism of acute alcohol ingestion. This study investigated the impact of 8-weeks prebiotics/probiotics supplementation on microbiome changes and responses to acute alcohol consumption.

METHODS

38 participants (21 females, 23.6 ± 3.4 kg m^-2, mean ± SD) attended the laboratory on two occasions separated by an 8-week intervention period. On each of these visits, a dose of alcohol (0.40 ± 0.04 g kg^-1, Vodka + Soda-Water) was consumed over 10 min. Breath alcohol concentration was sampled over 5 h and alcohol pharmacokinetics was analysed using WinNonlin non-compartmental modelling (C _max, t _max, AUC_last). For the intervention, participants were randomised to receive Placebo + Placebo (PLA), Placebo + Prebiotics (PRE), Probiotics + Placebo (PRO), or Probiotics + Prebiotics (SYN) in a double-blinded manner. Probiotics were a commercially available source of Lactobacillus acidophilus (NCFM^®) and Bifidobacterium lactis (Bi-07). Prebiotics were a commercially available source of Larch Gum (from Larix occidentalis). Placebo was microcrystalline cellulose. Each visit, participants provided a stool sample, which was analysed to determine the presence of L. acidophilus and B. lactis. Differences between trials were analysed using paired samples t tests.

RESULTS

Increased counts for at least one bacterial strain (L. acidophilus or B. lactis) were observed for all participants on SYN (n = 10) and PRO (n = 10) trials. No difference in C _max or t _max was observed between trials when analysed by treatment condition or microbiome outcome. A significant decrease in AUC_last was observed between trials for PLA (p = 0.039) and PRE (p = 0.030) treatments, and when increases in at least one bacterial strain (p = 0.003) and no microbiome changes (p = 0.016) were observed.

CONCLUSION

Consumption of probiotics appears to alter faecal counts of supplemental bacterial strains in otherwise healthy individuals. However, translation to any possible beneficial impact on alcohol metabolism remains to be elucidated.

Slow-release L-cysteine capsule prevents gastric mucosa exposure to carcinogenic acetaldehyde: results of a randomised single-blinded, cross-over study of Helicobacter-associated atrophic gastritis

INTRODUCTION

Helicobacter-induced atrophic gastritis with a hypochlorhydric milieu is a risk factor for gastric cancer. Microbes colonising acid-free stomach oxidise ethanol to acetaldehyde, a recognised group 1 carcinogen.

OBJECTIVE

To assess gastric production of acetaldehyde and its inert condensation product, non-toxic 2-methyl-1,3-thiazolidine-4-carboxylic acid (MTCA), after alcohol intake under treatment with slow-release L-cysteine or placebo.

METHODS

Seven patients with biopsy-confirmed atrophic gastritis, low serum pepsinogen and high gastrin-17 were studied in a cross-over single-blinded design. On separate days, patients randomly received 200 mg slow-release L-cysteine or placebo with intragastric instillation of 15% (0.3 g/kg) ethanol. After intake, gastric concentrations of ethanol, acetaldehyde, L-cysteine and MTCA were analysed.

RESULTS

Administration of L-cysteine increased MTCA (p < .0004) and decreased gastric acetaldehyde concentrations by 68% (p < .0001). The peak L-cysteine level was 7552 ± 2687 μmol/L at 40 min and peak MTCA level 196 ± 98 μmol/L at 80 min after intake. Gastric L-cysteine and MTCA concentrations were maintained for 3 h. The AUC for MTCA was 11-fold higher than acetaldehyde, indicating gastric first-pass metabolism of ethanol. With placebo, acetaldehyde remained elevated also at low ethanol concentrations representing 'non-alcoholic' beverages and food items.

CONCLUSIONS

After gastric ethanol instillation, slow-release L-cysteine eliminates acetaldehyde to form inactive MTCA, which remains in gastric juice for up to 3 h. High acetaldehyde levels indicate a marked gastric first-pass metabolism of ethanol resulting in gastric accumulation of carcinogenic acetaldehyde. Local exposure of the gastric mucosa to acetaldehyde can be mitigated by slow-release L-cysteine capsules.

The Influence of Mixers Containing Artificial Sweetener or Different Doses of Carbohydrate on Breath Alcohol Responses in Females

BACKGROUND

Breath alcohol responses may be affected by the presence of carbohydrate (CHO) in a beverage. This study investigated the impact of consuming alcohol with mixers containing various doses of CHO or an artificial sweetener on breath alcohol concentration (BrAC), ratings of intoxication and impairment, and cognitive performance in females.

METHODS

Twenty-six females (age 25.1 ± 0.7 years, mean ± standard deviation) completed a crossover study involving 4 trials. A dose of alcohol was consumed in each trial mixed with water (W), artificial sweetener (150 ± 1 mg aspartame [AS]), or CHO (15 g sucrose [15CHO] and 50 g sucrose [50CHO]). BrAC was sampled for 210 minutes following beverage ingestion and analyzed for peak BrAC and other parameters using WinNonlin noncompartmental pharmacokinetic modeling (c_max , t_max , area under the curve to the last measured time point [AUC_last ]). An objective measure of cognitive performance was assessed using a 4-choice reaction time (CRT) task. Estimation of BrAC, self-reported ratings of intoxication, and willingness to drive were recorded.

RESULTS

Mean peak BrAC was reduced in a dose-response manner when alcohol was consumed with CHO compared to both W and AS treatments (W: 0.054 ± 0.015%, AS: 0.052 ± 0.011%, 15CHO: 0.049 ± 0.008%, 50CHO: 0.038 ± 0.007%). No difference in peak BrAC was observed between W and AS treatments. WinNonlin parameters revealed significant differences in c_max and AUC_last (W: 4.80 ± 1.12 g/dl/h, AS: 4.61 ± 0.92 g/dl/h, 15CHO: 4.10 ± 0.86 g/dl/h, 50CHO: 3.11 ± 0.58 g/dL/h) when CHO-containing beverages were consumed compared to W and AS treatments. No difference in t_max or CRT was observed between treatments. Participants were able to detect subtle differences in peak BrAC and reported greater ability to drive after consuming 50CHO compared to W. However, participant's willingness to drive and CRT did not differ between treatments.

CONCLUSIONS

Consuming alcohol with CHO-containing mixers attenuates peak BrAC and reduces total alcohol exposure in a dose-response manner compared to drinks containing artificial sweetener or no additives. The effect of adding CHO to alcoholic beverages may translate to reduced risk of alcohol-related harms.

Ethanol oxidation and the inhibition by drugs in human liver, stomach and small intestine: Quantitative assessment with numerical organ modeling of alcohol dehydrogenase isozymes

Alcohol dehydrogenase (ADH) is the principal enzyme responsible for metabolism of ethanol. Human ADH constitutes a complex isozyme family with striking variations in kinetic function and tissue distribution. Liver and gastrointestinal tract are the major sites for first-pass metabolism (FPM). Their relative contributions to alcohol FPM and degrees of the inhibitions by aspirin and its metabolite salicylate, acetaminophen and cimetidine remain controversial. To address this issue, mathematical organ modeling of ethanol-oxidizing activities in target tissues and that of the ethanol-drug interactions were constructed by linear combination of the corresponding numerical rate equations of tissue constituent ADH isozymes with the documented isozyme protein contents, kinetic parameters for ethanol oxidation and the drug inhibitions of ADH isozymes/allozymes that were determined in 0.1 M sodium phosphate at pH 7.5 and 25 °C containing 0.5 mM NAD(+). The organ simulations reveal that the ADH activities in mucosae of the stomach, duodenum and jejunum with ADH1C*1/*1 genotype are less than 1%, respectively, that of the ADH1B*1/*1-ADH1C*1/*1 liver at 1-200 mM ethanol, indicating that liver is major site of the FPM. The apparent hepatic KM and Vmax for ethanol oxidation are simulated to be 0.093 ± 0.019 mM and 4.0 ± 0.1 mmol/min, respectively. At 95% clearance in liver, the logarithmic average sinusoidal ethanol concentration is determined to be 0.80 mM in accordance with the flow-limited gradient perfusion model. The organ simulations indicate that higher therapeutic acetaminophen (0.5 mM) inhibits 16% of ADH1B*1/*1 hepatic ADH activity at 2-20 mM ethanol and that therapeutic salicylate (1.5 mM) inhibits 30-31% of the ADH1B*2/*2 activity, suggesting potential significant inhibitions of ethanol FPM in these allelotypes. The result provides systematic evaluations and predictions by computer simulation on potential ethanol FPM in target tissues and hepatic ethanol-drug interactions in the context of tissue ADH isozymes.

Lipids and Oxidative Stress Associated with Ethanol-Induced Neurological Damage

The excessive intake of alcohol is a serious public health problem, especially given the severe damage provoked by chronic or prenatal exposure to alcohol that affects many physiological processes, such as memory, motor function, and cognitive abilities. This damage is related to the ethanol oxidation in the brain. The metabolism of ethanol to acetaldehyde and then to acetate is associated with the production of reactive oxygen species that accentuate the oxidative state of cells. This metabolism of ethanol can induce the oxidation of the fatty acids in phospholipids, and the bioactive aldehydes produced are known to be associated with neurotoxicity and neurodegeneration. As such, here we will review the role of lipids in the neuronal damage induced by ethanol-related oxidative stress and the role that lipids play in the related compensatory or defense mechanisms.

Differences between the measured blood ethanol concentration and the estimated concentration by Widmark's equation in elderly persons

BACKGROUND

The Widmark's equation (C [BAC]=A/p×r) is the most commonly used formula in legal medicine to estimate the blood alcohol concentration (BAC) from the amount of ingested ethanol and vice versa. Within a drinking experiment with a target BAC of 1.2 g/kg, a 75-year-old participant reached a maximum BAC of 1.83 g/kg and showed signs of severe ethanol intoxication, while the other nine subjects (age: 19-31 years) had BACs close to the target BAC. This incident brought up the question, if the Widmark's equation is an appropriate tool for aged persons.

METHODS

A drinking experiment with 50 elderly voluntary test persons (22 males, 28 females, mean age and range [males]: 69.7 years, 60-84 years, mean age and range [females]: 68.5 years, 61-78 years) was performed. The amount of ethanol leading to a BAC of 0.6 g/kg was estimated individually using the Widmark's equation (used Widmark factors: 0.7 for males, 0.6 for females). After drinking, the blood ethanol concentrations were measured using headspace gas chromatography/flame ionization detection.

RESULTS

The measured maximum BACs of the elderly participants were significantly higher (α=0.01) than the target BAC (mean maximum BAC and range: 0.627 g/kg, 0.3-0.81 g/kg, for males: 0.616 g/kg, 0.32-0.78 g/kg, for females: 0.635 g/kg, 0.3-0.81). The calculated Widmark factors showed a high coefficient of variation (for males: 0.7±0.138 [0.55-1.2, CV: 19.7%], for females 0.59±0.119 [0.46-1.08, CV: 20.2%]).

CONCLUSION

The results demonstrate that BAC calculations by Widmark's equation in elderly individuals may be complicated by a high variation of Widmark factors. There is a tendency to an elevation of the actual BAC with increasing age.

Genders and the concurrent use of cocaine and alcohol: Pharmacological aspects

AIMS

Gender-related differences in the pharmacological effects of addictive drug are an emerging issue. This review examines gender differences in both pharmacokinetic and pharmacodynamic aspects of alcohol and cocaine intake since they cause complex pharmacological interactions, not least the formation of the active metabolite cocaethylene.

METHODS

The MEDLINE database was searched from 1990 to 2014 in order to find articles related to gender differences in alcohol, cocaine and cocaethylene pharmacokinetics and pharmacodynamics.

RESULTS

Besides the well known gender differences in alcohol pharmacokinetics, women appear more susceptible to alcohol-mediated brain damage and seem to suffer more than men the acute effects of alcohol on hepatic and gonadal hormones. No significant gender differences have been found in the pharmacokinetics of cocaine taken alone; yet, in women pharmacological sensitivity to the drug seems to vary in relation to menstrual cycle; moreover, progesterone attenuates subjective effects of cocaine in women. Higher ratings at a subjective measure of mental/physical well-being have been observed in women when given cocaine and alcohol, alone or in combination. Finally, among subjects dependent on both alcohol and cocaine, men only benefit from naltrexone, whereas women used more cocaine during the trial and were less compliant to therapy than men.

CONCLUSIONS

The observed subtle gender differences in the pharmacokinetics and pharmacodynamics of both alcohol and cocaine may have no subtle influence on the natural history of the co-abuse of the two drugs by women.

Alcohol-medical drug interactions

Concomitant use of alcohol and medications may lead to potentially serious medical conditions. Increasing prescription medication abuse in today's society necessitates a deeper understanding of the mechanisms involved in alcohol-medication interactions in order to help prevent adverse events. Interactions of medications with alcohol result in altered bioavailability of the medication or alcohol (pharmacokinetic interactions) or modification of the effects at receptor or ion channel sites to alter behavioral or physical outcome (pharmacodynamic interactions). The nature of pharmacokinetic or pharmacodynamic interactions involved in alcohol-medication interactions may differ between acute and chronic alcohol use and be influenced by race, gender, or environmental or genetic factors. This review focuses on the mechanisms underlying pharmacokinetic and pharmacodynamic interactions between alcohol and medications and provides examples for such interactions from replicated research studies. In conclusion, further translational research is needed to address several gaps in our current knowledge of alcohol-medication interactions, including those under various pathologic conditions.

Ethanol metabolism and its effects on the intestinal epithelial barrier

Ethanol is widely consumed and is associated with an increasing global health burden. Several reviews have addressed the effects of ethanol and its oxidative metabolite, acetaldehyde, on the gastrointestinal (GI) tract, focusing on carcinogenic effects or alcoholic liver disease. However, both the oxidative and the nonoxidative metabolites of ethanol can affect the epithelial barrier of the small and large intestines, thereby contributing to GI and liver diseases. This review outlines the possible mechanisms of ethanol metabolism as well as the effects of ethanol and its metabolites on the intestinal barrier. Limited studies in humans and supporting in vitro data have indicated that ethanol as well as mainly acetaldehyde can increase small intestinal permeability. Limited evidence also points to increased colon permeability following exposure to ethanol or acetaldehyde. In vitro studies have provided several mechanisms for disruption of the epithelial barrier, including activation of different cell-signaling pathways, oxidative stress, and remodeling of the cytoskeleton. Modulation via intestinal microbiota, however, should also be considered. In conclusion, ethanol and its metabolites may act additively or even synergistically in vivo. Therefore, in vivo studies investigating the effects of ethanol and its byproducts on permeability of the small and large intestines are warranted.

Artificial sweeteners versus regular mixers increase breath alcohol concentrations in male and female social drinkers

BACKGROUND

Limited research suggests that alcohol consumed with an artificially sweetened mixer (e.g., diet soft drink) results in higher breath alcohol concentrations (BrACs) compared with the same amount of alcohol consumed with a similar beverage containing sugar. The purpose of this study was to determine the reliability of this effect in both male and female social drinkers and to determine if there are measureable objective and subjective differences when alcohol is consumed with an artificially sweetened versus sugar-sweetened mixer.

METHODS

Participants (n = 16) of equal gender attended 3 sessions where they received 1 of 3 doses (1.97 ml/kg vodka mixed with 3.94 ml/kg Squirt, 1.97 ml/kg vodka mixed with 3.94 ml/kg diet Squirt, and a placebo beverage) in random order. BrACs were recorded, as were self-reported ratings of subjective intoxication, fatigue, impairment, and willingness to drive. Objective performance was assessed using a cued go/no-go reaction time task.

RESULTS

BrACs were significantly higher in the alcohol + diet beverage condition compared with the alcohol + regular beverage condition. The mean peak BrAC was 0.091 g/210 l in the alcohol + diet condition compared with 0.077 g/210 l in the alcohol + regular condition. Cued go/no-go task performance indicated the greatest impairment for the alcohol + diet beverage condition. Subjective measures indicated that participants appeared unaware of any differences in the 2 alcohol conditions, given that no significant differences in subjective ratings were observed for the 2 alcohol conditions. No gender differences were observed for BrACs, and objective and subjective measures.

CONCLUSIONS

Mixing alcohol with a diet soft drink resulted in elevated BrACs, as compared with the same amount of alcohol mixed with a sugar-sweetened beverage. Individuals were unaware of these differences, a factor that may increase the safety risks associated with drinking alcohol.

In silico Models of Alcohol Dependence and Treatment

In this paper we view alcohol dependence and the response to treatment as a recurrent bio-behavioral process developing in time and propose formal models of this process combining behavior and biology in silico. The behavioral components of alcohol dependence and treatment are formally described by a stochastic process of human behavior, which serves as an event generator challenging the metabolic system. The biological component is driven by the biochemistry of alcohol intoxication described by deterministic models of ethanol pharmacodynamics and pharmacokinetics to enable simulation of drinking addiction in humans. Derived from the known physiology of ethanol and the literature of both ethanol intoxication and ethanol absorption, the different models are distilled into a minimal model (as simple as the complexity of the data allows) that can represent any specific patient. We use these modeling and simulation techniques to explain responses to placebo and ondansetron treatment observed in clinical studies. Specifically, the response to placebo was explained by a reduction of the probability of environmental reinforcement, while the effect of ondansetron was explained by a gradual decline in the degree of ethanol-induced neuromodulation. Further, we use in silico experiments to study critical transitions in blood alcohol levels after specific average number of drinks per day, and propose the existence of two critical thresholds in the human - one at 5 and another at 11 drinks/day - at which the system shifts from stable to critical and to super critical state indicating a state of alcohol addiction. The advantages of such a model-based investigation are that (1) the process of instigation of alcohol dependence and its treatment can be deconstructed into meaningful steps, which allow for individualized treatment tailoring, and (2) physiology and behavior can be quantified in different (animal or human) studies and then the results can be integrated in silico.

Commentary on Rossheim and Thombs (2011): artificial sweeteners, caffeine, and alcohol intoxication in bar patrons

BACKGROUND

This commentary discusses the paper by Rossheim and Thombs (Alcohol Clin Exp Res 35, 2011), which examined the relationship between type of alcohol mixer (regular caffeinated cola, diet caffeinated cola, energy drink, or no mixer) and breath alcohol readings in bar patrons.

METHODS

The significance of the findings of this study and new unaddressed questions for the field are discussed.

RESULTS

Rossheim and Thombs (2011) reported that breath alcohol concentration readings were highest when patrons reported the consumption of caffeine mixers that were artificially sweetened (i.e., diet cola), after adjusting for potential confounds. Women were more likely to consume diet cola-caffeinated mixed drinks.

CONCLUSIONS

The findings from this field study raise several new interesting questions. Given the reported gender difference in consumption of diet cola-caffeinated mixed drinks, more research is needed regarding gender differences in gastric emptying time for alcoholic beverages mixed with artificially sweetened versus sucrose sweetened caffeinated drinks. In addition, the recent explosion in the energy drink market has resulted in the availability of sugar-free or diet versions of most energy drink products. The implications of mixing diet energy drinks with alcohol are unknown.

Kinetics of ethanol decay in mouth- and nose-exhaled breath measured on-line by selected ion flow tube mass spectrometry following varying doses of alcohol

A study has been carried out of the decay of ethanol in mouth-exhaled and nose-exhaled breath of two healthy volunteers following the ingestion of various doses of alcohol at different dilutions in water. Concurrent analyses of sequential single breath exhalations from the two volunteers were carried out using selected ion flow tube mass spectrometry, SIFT-MS, on-line and in real time continuously over some 200 min following each alcohol dose by simply switching sampling between the two volunteers. Thus, the time interval between breath exhalations was only a few minutes, and this results in well-defined decay curves. Inspection of the mouth-exhaled and nose-exhaled breath data shows that mouth contamination of ethanol diminished to insignificant levels after a few minutes. The detailed results of the analyses of nose-exhaled breath show that the peak levels and the decay rates of breath ethanol are dependent on the ethanol dose and the volume of ethanol/water mixture ingested. From these data, both the efficiency of the first-pass metabolism of ethanol and the indications of gastric emptying rates at the various doses and ingested volumes have been obtained for the two volunteers. Additionally and simultaneously, acetaldehyde, acetic acid and acetone were measured in each single breath exhalation. Acetaldehyde, the primary product of ethanol metabolism, is seen to track the breath ethanol. Acetic acid, a possible secondary product of this metabolism, was detected in the exhaled breath, but was shown to largely originate in the oral cavity. Breath acetone was seen to increase over the long period of measurement due to the depletion of nutrients.

Combined exposure to nicotine and ethanol in adolescent mice differentially affects anxiety levels during exposure, short-term, and long-term withdrawal

Smoking and consumption of alcoholic beverages are frequently associated during adolescence. This association could be explained by the cumulative behavioral effects of nicotine and ethanol, particularly those related to anxiety levels. However, despite epidemiological findings, there have been few animal studies of the basic neurobiology of the combined exposure in the adolescent brain. In the present work we assessed, through the use of the elevated plus maze, the short- and long-term anxiety effects of nicotine (NIC) and/or ethanol (ETOH) exposure during adolescence (from the 30th to the 45th postnatal day) in four groups of male and female C57BL/6 mice: (1) Concomitant NIC (nicotine free-base solution (50 microg/ml) in 2% saccharin to drink) and ETOH (ethanol solution (25%, 2 g/kg) i.p. injected every other day) exposure; (2) NIC exposure; (3) ETOH exposure; (4) Vehicle. C57BL/6 mice were selected, in spite of the fact that they present slower ethanol metabolism, because they readily consume nicotine in the concentration used in the present study. During exposure (45th postnatal day: PN45), our results indicated that ethanol was anxiolytic in adolescent mice and that nicotine reverted this effect. Short-term drug withdrawal (PN50) elicited sex-dependent effects: exposure to nicotine and/or ethanol was anxiogenic only for females. Although neither nicotine nor ethanol effects persisted up to 1 month postexposure (PN75), the coadministration elicited an anxiogenic response. In spite of the fact that generalizations based on the results from a single strain of mice are prone to shortcomings, our results suggest that the deficient response to the anxiolytic effects of ethanol in adolescents co-exposed to nicotine may drive higher ethanol consumption. Additionally, increased anxiety during long-term smoking and drinking withdrawal may facilitate relapse to drug use.

The effect of ethanol on the release of opioids from oral prolonged-release preparations

Recent experience has prompted the US FDA to consider whether ethanol ingestion may modify the release characteristics of prolonged-release formulations, where dose dumping may be an issue for patient safety. The influence of ethanol on the in vitro release of opioid drugs from some prolonged-release formulations utilizing different release technologies was examined. Results indicated that the prolonged-release mechanisms remained intact under the testing conditions, although one product showed initial sensitivity to ethanol in its release characteristics. Nevertheless, in this case, extrapolation of the findings to likely outcome in vivo indicated no risk of dose-dumping. It is proposed that prolonged-release medicinal products should be tested during development to ensure robustness to the effects of ethanol on drug release.

Age, alcohol metabolism and liver disease

PURPOSE OF REVIEW

Alcohol consumption among the elderly has increased. Alcohol metabolism changes with age and the elderly are more sensitive to the toxic effects; this increased consumption is therefore of great clinical relevance.

RECENT FINDINGS

Metabolism of ethanol changes with advancing age because activity of the enzymes involved, such as alcohol and acetaldehyde dehydrogenase and cytochrome P-4502E1, diminish with age. The water distribution volume also decreases with age. Both lead to increased blood concentrations of ethanol. Also, elderly people take more drugs, and ethanol and these drugs may interact; therefore, alcohol consumption can modify serum drug concentrations and their toxicity. Finally, elderly people may suffer more frequently from other types of liver disease, and alcohol may exacerbate these.

SUMMARY

Over recent decades alcohol consumption has increased among those who are older than 65 years. Alcohol is more toxic in the ageing organism because of changes in its metabolism, distribution and elimination, which lead to central nervous system effects at lower levels of intake; also, ageing organs such as brain and liver are more sensitive to the toxicity of alcohol. For these reasons, alcohol should be used in moderation, especially among those of older age.

Lactational state modifies alcohol pharmacokinetics in women

BACKGROUND

Given the physiological adaptations of the digestive system during lactation, the present study tested the hypothesis that lactation alters alcohol pharmacokinetics.

METHODS

Lactating women who were exclusively breastfeeding a 2- to 5-month-old infant and 2 control groups of nonlactating women were studied. The first control group consisted of women who were exclusively formula-feeding similarly aged infants, whereas the other consisted of women who had never given birth. A within-subjects design study was conducted such that women drank a 0.4 g/kg dose of alcohol following a 12-hour overnight fast during one test session (fasted condition) or 60 minutes after consuming a standard breakfast during the other (fed condition). Blood alcohol concentration (BAC) levels and mood states were obtained at fixed intervals before and after alcohol consumption.

RESULTS

Under both conditions, the resultant BAC levels at each time point were significantly lower and the area under the blood alcohol time curve were significantly smaller in lactating women when compared with the 2 groups of nonlactating women. That such changes were due to lactation per se and not due to recent parturient events was suggested by the finding that alcohol pharmacokinetics of nonlactating mothers, who were tested at a similar time postpartum, were no different from women who had never given birth. Despite lower BAC levels in lactating mothers, there were no significant differences among the 3 groups of women in the stimulant effects of alcohol. However, lactating women did differ in the sedative effects of alcohol when compared with nulliparous but not formula-feeding mothers. That is, both groups of parous women felt sedated for shorter periods of time when compared with nulliparous women.

CONCLUSIONS

The systemic availability of alcohol was diminished during lactation. However, the reduced availability of alcohol in lactating women did not result in corresponding changes in the subjective effects of alcohol.

Alcohol dehydrogenase genetic polymorphisms, low-to-moderate alcohol consumption, and risk of breast cancer

BACKGROUND

In vitro, human isoenzymes encoded by genes homozygous for the ADH1C*1 or ADH1B*2 alleles metabolize ethanol to acetaldehyde at a faster rate than those homozygous for the ADH1C*2 or ADH1B*1 allele. Because alcohol is a known risk factor for breast cancer, we evaluated the joint association of genetic variants in ADH and alcohol consumption in relation to breast cancer.

METHODS

A nested case-control study of 321 cases and matched controls was conducted. Five single nucleotide polymorphisms (SNPs) in the ADH1C and ADH1B genes were genotyped. Logistic regression was used to assess odds ratios (ORs) and 95% confidence limits (CIs) for each SNP. Haplotype analysis of all 5 SNPs was also undertaken.

RESULTS

Among drinkers, the median intake of total alcohol was 13 g/wk (10th-90th percentiles; 4.5-135.9) in cases and 18 g/wk (10th-90th percentiles; 4.5-104.1) in controls. Women who drank alcohol tended to be at an increased risk of developing breast cancer compared with those who did not drink (OR=1.40%, 95% CI 0.97-2.03), particularly those who were premenopausal at the time of breast cancer diagnosis (OR=2.69%, 95% CI: 1.00-7.26). Of the known functional alleles, breast cancer risk was not significantly increased among carriers of at least 1 ADH1C*1 or ADH1B*2 allele, when compared with those homozygous for the genotype at each locus. However, breast cancer risk tended to be lower among women who inherited the G allele at ADH1B IVS1+896A>G (OR=0.62, 95% CI 0.37-1.04). Overall haplotype frequencies were not significantly different between cases and controls.

CONCLUSIONS

In this study low levels of alcohol are associated with a modest increase in breast cancer risk that is not altered by known functional allelic variants of the ADH1B and 1C gene. The protective association conferred by the G allele at ADH1B IVS1+896A>G needs further evaluation.

Artificially sweetened versus regular mixers increase gastric emptying and alcohol absorption

BACKGROUND

Mixed alcoholic drinks are increasingly being consumed in "diet" varieties, which could potentially empty more rapidly from the stomach and thereby increase the rate of alcohol absorption when compared with "regular" versions containing sugar.

METHODS

We studied 8 healthy males twice in randomized order. On each day, they consumed an orange-flavored vodka beverage (30 g ethanol in 600 mL), made with either "regular" mixer containing sucrose (total 478 kcal), or "diet" mixer (225 kcal).

RESULTS

Gastric half-emptying time measured by ultrasound (mean+/-standard deviation) was less for the "diet" than the "regular" drink (21.1+/-9.5 vs 36.3+/-15.3 minutes, P <.01). Both the peak blood ethanol concentration (0.053+/-0.006 vs 0.034+/-0.008 g%, P <.001) and the area under the blood ethanol concentration curve between 0 and 180 minutes (5.2+/-0.7 vs 3.2+/-0.7 units, P <.001) were greater with the "diet" drink.

CONCLUSIONS

Substitution of artificial sweeteners for sucrose in mixed alcoholic beverages may have a marked effect on the rate of gastric emptying and the blood alcohol response.

Effects of Hu Gan Ling on lytic enzymes of ethanol in experimental rats

AIM: To investigate the effects of Hu Gan Ling on lytic enzymes of ethanol in the experimental rats.

METHODS: The rat model of liver injury was induced intragastically by alcohol administration. After treatment with Essentiale, high- and low-dose Hu Gan Ling, the alcohol concentration in serum was determined by dual wavelength spectrophotometry, and the contents of catalase (CAT) and alcohol dehydrogenase (ADH) in liver homogenate were detected according to the instruction of kit and by spectrophotometric method, respectively. The expressions of ADH and CYP450ⅡE1 mRNA were examined by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: In comparison with that in the normal controls, the serum content of alcohol in model group was significantly increased (545.7 ± 108.85 mg/L vs -51.4 ± 2.83 mg/L, P < 0.05), but the tissue content of ADH or CAT was significantly decreased (667 ± 272 nkat/L vs 1884 ± 650 nkat/L, P < 0.05; 112 ± 29 nkat vs 255 ± 43 nkat, P < 0.05). However, Hu Gan Ling reduced the serum content of alcohol (low dose: 248.5 ± 96.63 mg/L; high dose: -0.1 ± 33.94 mg/L; both P < 0.01), but increased the tissue content of ADH (low dose: 1184 ± 422 nkat/L; high dose: 1550 ± 458 nkat/L; both P < 0.05) or CAT (low dose: 202 ± 31 nkat/L; high dose: 167 ± 34 nkat/L; both P < 0.05). After modeling, the expression of CYP450ⅡE1 mRNA was significantly down-regulated (10 ± 2 vs 15 ± 2, P < 0.01), and then further down-regulated by Hu Gan Ling treatment (high dose: 8 ± 2, P < 0.05). The mRNA expression of ADH was not markedly changed after modeling and drugs treatment (P > 0.05).

CONCLUSION: Hu Gan Ling can activate the lytic enzymes of ethanol, and enhance the intracorporal ethanol metabolism.

Functional Assessment of Human Alcohol Dehydrogenase Family in Ethanol Metabolism: Significance of First-Pass Metabolism

BACKGROUND

Alcohol dehydrogenase (ADH) is the principal enzyme responsible for ethanol metabolism in mammals. Human ADH constitutes a unique complex enzyme family with no equivalent counterpart in experimental rodents. This study was undertaken to quantitatively assess relative contributions of human ADH isozymes and allozymes to hepatic versus gastric metabolism of ethanol in the context of the entire family.

METHODS

Kinetic parameters for ethanol oxidation for recombinant human class I ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, and ADH1C2; class II ADH2; class III ADH3; and class IV ADH4 were determined in 0.1 M sodium phosphate at pH 7.5 over a wide range of substrate concentrations in the presence of 0.5 mM NAD+. The composite numerical formulations for organ steady-state ethanol clearance were established by summing up the kinetic equations of constituent isozymes/allozymes with the assessed contents in livers and gastric mucosae with different genotypes.

RESULTS

In ADH1B*1 individuals, ADH1B1 and ADH1C allozymes were found to be the major contributors to hepatic-alcohol clearance; ADH2 made a significant contribution only at high ethanol levels (> 20 mM). ADH1B2 was the major hepatic contributor in ADH1B*2 individuals. ADH1C allozymes were the major contributor at low ethanol (< 2 mM), whereas ADH1B3 the major form at higher levels (> 10 mM) in ADH1B*3 individuals. For gastric mucosal-alcohol clearance, the relative contributions of ADH1C allozymes and ADH4 were converse as ethanol concentration increased. It was assessed that livers with ADH1B*1 may eliminate approximately 95% or more of single-passed ethanol as inflow sinusoidal alcohol reaches approximately 1 mM and that stomachs with different ADH1C genotypes may remove 20% to 30% of single-passed alcohol at the similar level in mucosal cells.

CONCLUSIONS

This work provides just a model, but a strong one, for quantitative assessments of ethanol metabolism in the human liver and stomach. The results indicate that the hepatic-alcohol clearance of ADH1B*2 individuals is higher than that of the ADH1B*1 and those of the ADH1B*3 versus the ADH1B*1 vary depending on sinusoidal ethanol levels. The maximal capacity for potential alcohol first-pass metabolism in the liver is greater than in the stomach.