Alcohol use and prognosis in patients with coronary heart disease

Synaptic Mechanisms of Ethanol Tolerance and Neuroplasticity: Insights from Invertebrate Models

Alcohol tolerance is a neuroadaptive response that leads to a reduction in the effects of alcohol caused by previous exposure. Tolerance plays a critical role in the development of alcohol use disorder (AUD) because it leads to the escalation of drinking and dependence. Understanding the molecular mechanisms underlying alcohol tolerance is therefore important for the development of effective therapeutics and for understanding addiction in general. This review explores the molecular basis of alcohol tolerance in invertebrate models, Drosophila and C. elegans, focusing on synaptic transmission. Both organisms exhibit biphasic responses to ethanol and develop tolerance similar to that of mammals. Furthermore, the availability of several genetic tools makes them a great candidate to study the molecular basis of ethanol response. Studies in invertebrate models show that tolerance involves conserved changes in the neurotransmitter systems, ion channels, and synaptic proteins. These neuroadaptive changes lead to a change in neuronal excitability, most likely to compensate for the enhanced inhibition by ethanol.

Moderate alcohol use and health: a consensus document

AIMS

The aim of this consensus paper is to review the available evidence on the association between moderate alcohol use, health and disease and to provide a working document to the scientific and health professional communities.

DATA SYNTHESIS

In healthy adults and in the elderly, spontaneous consumption of alcoholic beverages within 30 g ethanol/d for men and 15 g/d for women is to be considered acceptable and do not deserve intervention by the primary care physician or the health professional in charge. Patients with increased risk for specific diseases, for example, women with familiar history of breast cancer, or subjects with familiar history of early cardiovascular disease, or cardiovascular patients should discuss with their physician their drinking habits. No abstainer should be advised to drink for health reasons. Alcohol use must be discouraged in specific physiological or personal situations or in selected age classes (children and adolescents, pregnant and lactating women and recovering alcoholics). Moreover, the possible interactions between alcohol and acute or chronic drug use must be discussed with the primary care physician.

CONCLUSIONS

The choice to consume alcohol should be based on individual considerations, taking into account the influence on health and diet, the risk of alcoholism and abuse, the effect on behaviour and other factors that may vary with age and lifestyle. Moderation in drinking and development of an associated lifestyle culture should be fostered.

Alcohol consumption and risk of heart failure: a meta-analysis

BACKGROUND

Heart failure is highly prevalent among older adults and is associated with high treatment costs. Identifying modifiable determinants of heart failure may help in prevention. Alcohol consumption has emerged as a modifiable risk factor for cardiovascular diseases. Although many studies have suggested a positive association between heavy drinking and cardiomyopathy, the association between infrequent or light-to-moderate drinking and heart failure risk has been less conclusive.

PURPOSE

To examine the relation between various levels of alcohol intake and incident heart failure.

METHODS

We conducted a meta-analysis of 6 studies obtained through a PubMed literature search. Alcohol drinkers were classified as never, former, and current drinkers of 0.1 to 0.9, 1 to 7, 8 to 14, and > 14 drinks per week.

RESULTS

Compared with never drinkers, the pooled relative risks were 1.16 (95% confidence interval [CI], 0.90-1.51) for former drinkers, 0.90 (95% CI, 0.83-0.98), 0.80 (95% CI, 0.73-0.88), 0.78 (95% CI, 0.65-0.95), and 0.77 (95% CI, 0.63-0.95) for current drinkers of 0.1 to 0.9, 1 to 7, 8 to 14, and > 14 drinks per week, respectively, in a random effects model.

CONCLUSION

These data suggest that infrequent and light-to-moderate drinking is associated with a lower risk of heart failure.

Prevention of cardiovascular risk by moderate alcohol consumption: epidemiologic evidence and plausible mechanisms

An inverse association between moderate alcohol intake and cardiovascular risk, in particular coronary disease and ischemic stroke, has been shown in many epidemiologic studies. In addition, several other diseases are also known to occur less frequently in moderate drinkers than in non-drinkers, whereas excess of drinking is invariably harmful. However, some concern has been recently raised about the possibility that at all dosages the harm of alcohol could overcome its beneficial effects. We present here the epidemiologic and mechanistic evidence to support the protective effect of moderate alcohol intake against cardiovascular disease and all-cause mortality.

Alcohol consumption and mortality in patients with cardiovascular disease: a meta-analysis

OBJECTIVES

The purpose of this study was to quantify the relation between alcohol consumption and cardiovascular and total mortality in patients with a history of cardiovascular events.

BACKGROUND

Regular, moderate alcohol consumption by healthy people is associated with lower cardiovascular and all-cause mortality. No extensive meta-analysis is presently available on the possible association of alcohol consumption with secondary events in patients with cardiovascular disease.

METHODS

Articles were retrieved through October 2009 by search in PubMed and EMBASE. Fifty-four publications were identified, but only 8 were selected for our analyses, including 16,351 patients with a history of cardiovascular disease. Secondary events were cardiovascular or all-cause mortality. All selected studies were prospective. Data were pooled with a weighted, least-squares regression analysis of second-order fractional polynomial models.

RESULTS

The meta-analysis on cardiovascular mortality showed a J-shaped pooled curve with a significant maximal protection (average 22%) by alcohol at approximately 26 g/day. In the meta-analysis on mortality for any cause, J-shaped pooled curves were observed in the overall analysis (average maximal protection of 18% in the range of 5 to 10 g/day) and in all subgroups according to either the type of patients or the characteristics of the studies.

CONCLUSIONS

In patients with cardiovascular disease, light to moderate alcohol consumption (5 to 25 g/day) was significantly associated with a lower incidence of cardiovascular and all-cause mortality.

Nutrition, hormetic stress and health

Hormesis defines an effect where exposure to a low dose of a toxic agent results in a beneficial response. It has been described in organisms exposed to low-dose radiation, heat stress, and chemicals. The effect is characterised by a J-shaped dose-response as opposed to a linear dose-response. Confirmation of the general phenomena of hormesis has proved difficult due to the lack of appropriate methodology and the absence of well-defined mechanisms to support the experimental observations. In the nutritional field there are few reports of its existence. The clearest illustration of the effect is seen in animals that are energy restricted when there is a clear benefit in the reduction of age-related disease, and an extension of maximum lifespan. DNA microarray experiments have shown that there is a down regulation of the stress-response genes that are up regulated through the ageing process. Electrophilic phytochemicals, that have been shown to have beneficial health effects at low doses, up regulate the antioxidant-electrophile response element. This probably occurs through an alteration in the redox state of the target cells which causes activation of protein kinases, the activation of the Nrf2 transcription factor and the up regulation of the phase II enzymes, similar to responses that occur under mild chemical stress. This situation might enable organisms to adapt to stress such that the effects of a subsequent exposure to a harmful challenge are reduced. There may be a permanent alteration in cellular homeostasis, or redox state, if the low level exposure is maintained. It remains to be proven if such a situation occurs in response to chronic low-dose exposure to dietary phytochemicals such that the target cells are better able to respond to a subsequent stress challenge.

Alcohol consumption and blood lipids in elderly coronary patients

Alcohol may have a beneficial effect on coronary heart disease (CHD) that could be mediated by elevation of high-density lipoprotein cholesterol (HDLC). Data on alcohol consumption and blood lipids in coronary patients are scarce. We studied whether total ethanol intake and consumption of specific types of beverages are associated with blood lipids in older subjects with CHD. Blood lipids were measured in 1052 myocardial infarction patients aged 60 to 80 years (78% male). Intake of alcoholic beverages, total ethanol, and macronutrients was assessed by food frequency questionnaire. Seventy percent of the subjects used lipid-lowering medication. Total cholesterol was on average 5.14 mmol/L, and HDLC was on average 1.28 mmol/L. Among men, total ethanol intake was positively associated with HDLC (difference of 0.094 mmol/L for > or =15 g/d vs 0 g/d, P = .024), whereas the association with HDLC among women was not significant (difference of 0.060 mmol/L for > or =5 g/d vs 0 g/d, P = .560) after adjustment for dietary, lifestyle, and CHD risk factors. Liquor consumption was weakly positively associated with HDLC in men (P = .045). Beer consumption in men and wine consumption in women were also positively associated with HDLC, but were not significant in the fully adjusted model. In conclusion, moderate alcohol consumption may elevate HDLC in treated post-myocardial infarction patients. This may be due to ethanol and not to other beneficial substances in alcoholic beverages. Based on this finding, further research needs to be done to examine the effects of the residual substances from different types of alcoholic beverages on HDLC.

Alcohol consumption as a trigger of recurrent gout attacks

BACKGROUND

Alcohol consumption has long been considered a trigger for recurrent gout attacks; however, this hypothesis has not been formally tested.

METHODS

We conducted an Internet-based case-crossover study to assess several putative risk factors, including alcohol consumption, thought to trigger recurrent gout attacks. Subjects who had an attack within the past year were recruited online and asked to provide access to medical records pertaining to their gout. Data were obtained on the amount and type of alcoholic beverage consumed on each day over the 2-day period before a gout attack and on each day over a 2-day period during the intercritical period. We examined the amount and type of alcohol consumption and the risk of recurrent gout attacks using a conditional logistic regression adjusting for diuretic use and purine intake.

RESULTS

A total of 197 subjects were recruited online over a 10-month period. Of those, 179 (91%) fulfilled the American College of Rheumatology Criteria for gout. Compared with no alcohol consumption, odds ratios for recurrent gout attacks were 1.1, 0.9, 2.0, and 2.5 for 1 to 2, 3 to 4, 5 to 6, and 7 or more drinks consumed over the 2-day period, respectively (P<.005). A dose-response relationship of risk of gout attacks was more evident for alcohol consumed over the last 24 hours. An increased risk of recurrent gout attacks was found for each type of beverage consumed.

CONCLUSION

Alcohol consumption triggers recurrent gout attacks. This effect was likely to occur within 24 hours after its consumption.

National Institute on Alcohol Abuse and Alcoholism Report on Moderate Drinking

In support of the 2005 update of the U.S. Department of Agriculture/U.S. Department of Health and Human Services Dietary Guidelines, the National Institute on Alcohol Abuse and Alcoholism was asked to assess the strength of the evidence related to health risks and potential benefits of moderate alcohol consumption, with particular focus on the areas of cardiovascular disease, breast cancer, obesity, birth defects, breastfeeding, and aging. The findings were reviewed by external researchers with extensive research backgrounds on the consequences and benefits of alcohol consumption. This report now serves as the National Institutes of Health's formal position paper on the health risks and potential benefits of moderate alcohol use.

Boiled or Filtered Coffee?

Caffeine is the most widely consumed psychostimulant drug in the world that mostly is consumed in the form of coffee. Whether caffeine and/or coffee consumption contribute to the development of cardiovascular disease (CVD), the single leading cause of death in the US, is unclear.This article examines the effects of caffeine intake, both alone and via coffee consumption, on key blood markers of CVD risk: lipoproteins (cholesterol, triglycerides), fibrinogen (a biomarker of blood clotting) and C-reactive protein (CRP; a biomarker of inflammation). These blood markers and their role in the development of CVD are reviewed first. Studies examining caffeine and coffee effects on each of these blood markers are then presented. Next, biobehavioural moderators of the relationship between caffeine and/or coffee consumption and CVD are discussed, including genetics, sex and tobacco smoking. The literature indicates a strong relationship between boiled, unfiltered coffee consumption and elevated cholesterol levels; however, there is a critical gap in the literature regarding the effects of coffee or caffeine consumption on fibrinogen or CRP, which is an independent predictor of CVD risk. Available studies are limited by small samples sizes, inclusion of only men (or few women) and unrepresented age or ethnic groups. Thiere is a critical need for controlled laboratory and epidemiological studies that include fibrinogen and CRP markers of CVD risk before conclusions can be drawn regarding the health effects of caffeine and/or coffee in a normal, healthy population of men and women.

Alcohol consumption and metabolic syndrome: does the type of beverage matter?

OBJECTIVE

To examine the association between total and beverage-specific alcohol consumption and the prevalence odds of metabolic syndrome (MS).

RESEARCH METHODS AND PROCEDURES

Using a cross-sectional design, we studied 4510 white participants of the National Heart, Lung, and Blood Institute Family Heart Study. We used generalized estimating equations adjusting for age, education, risk group, smoking, physical activity, diabetes mellitus, coronary heart disease, energy intake, energy from fat, fruits, and vegetables, dietary cholesterol, dietary fiber, and use of multivitamins to estimate the prevalence odds of MS by alcohol intake.

RESULTS

Compared with never-drinkers, multivariate odds ratios (95% confidence interval) for MS were 1.12 (0.85 to 1.49), 0.68 (0.36 to 1.28), 0.72 (0.50 to 1.03), 0.66 (0.44 to 0.99), and 0.80 (0.55 to 1.16) among men who were former drinkers and who were current drinkers of 0.1 to 2.5, 2.6 to 12.0, 12.1 to 24.0, and >24.0 g/d of alcohol, respectively (p for linear trend 0.018). Corresponding values for women were 0.86 (0.69 to 1.09), 0.80 (0.43 to 1.34), 0.47 (0.33 to 0.66), 0.47 (0.30 to 0.74), and 0.39 (0.21 to 0.74), respectively (p for trend < 0.0001). The reduced prevalence odds of MS was observed across all beverage types: compared with never-drinkers, multivariate adjusted odds ratios (95% confidence interval) of MS were 0.32 (0.14 to 0.73), 0.42 (0.23 to 0.77), 0.57 (0.30 to 1.09), and 0.56 (0.36 to 0.88) for subjects who consumed >7 drinks/wk of wine only, beer only, spirits only, and more than one type of beverage, respectively.

DISCUSSION

Our data indicate that alcohol consumption is associated with a lower prevalence of MS irrespective of the type of beverage consumed. Prospective studies are needed to confirm these findings and to assess the influence of drinking patterns on the alcohol-MS association.

Myocardial infarction and cardiac complications in emergency department patients admitted to the intensive care unit with gastrointestinal hemorrhage

Patients admitted with significant gastrointestinal hemorrhage (GIH) often experience in-hospital cardiac complications. This retrospective study examined 68 patients admitted from the Emergency Department to the Intensive Care Unit (ICU) over a 1-year period. The patients were 75% Caucasian, 60% male, with a mean age of 57 +/- 19 years. Medical co-morbidity was noted in 70%, and 54% of patients had a history of significant alcohol use. A systolic blood pressure < 100 mm Hg was present in 26%, hemoglobin < 7 mg/dL in 32%, and three patients (4%) expired. Death, acute myocardial infarction or other cardiac complications were noted in 32% of patients. Patients older than 60 years were three times more likely to have a complicated course than were younger patients, and those with a co-morbidity were 14.8 times more likely. Patients with a history of significant alcohol use were 31% less likely to have an inpatient complication than those without such a history. Regression analysis supported the protective effect of a history of significant alcohol use and also demonstrated that a history of peptic ulcer disease was predictive of inpatient complications. Older GIH patients and those with co-morbidities may benefit from ICU disposition given their greater risk. Younger patients presenting with hematemesis and a history of significant alcohol use tended to have fewer complications such that it may be possible to manage these patients outside of the ICU if hemodynamically stable.

Effects of low ethanol doses on heart rhythm in rabbits

Effects of low ethanol doses on the vagosympathetic mechanisms of heart rhythm regulation were studied in rabbits. Analysis of heart rhythm variability showed that single intragastric administration of 0.5 mg/kg ethanol caused tachycardia in animals with initial predominance of vagal activity and bradycardia in animals with predominating sympathetic mechanisms. This was associated with general activation of all regulatory effects on the heart rhythm and a drastic increase in power spectrum for all frequency ranges, though with a certain deficiency of vagal effects. However, after 24 h the vagal component of the spectrum drastically increased in animals of both groups, while other parameters did not differ from the control. Presumably, this rebound can be used as a physiological marker, ethanol tolerance measure, formation of the abstinence syndrome and liability to alcoholism.