The effects of alcohol on blood pressure and electrolytes

[Canada's guidance on alcohol and health : A paradigm shift]

Alcohol is a socially accepted food and beverage and as a cultural asset is also part of religious rituals. It can be an intoxicant and an addictive substance. It is also a noxious substance as around 3 million people worldwide die every year as a result of alcohol consumption. With the publication by Zhao et al. 2023 the relationship between the quantity of alcohol consumption and mortality reached a new level and changed the recommendations of Canada's Guidance on Alcohol and Health. The J‑curve of the French paradox became a linear relationship between alcohol consumption and mortality because the review of several control groups in previous studies revealed a recruitment error from abstinent ex-drinkers. In their systematic analysis, taking this bias into account the assessment of small amounts of alcohol as a cardioprotective stimulant had to be revised. This is a paradigm shift.

QTc prolongation in adolescents with acute alcohol intoxication

In adults, alcohol intoxication is associated with prolongation of the QT interval corrected for heart rate (QTc). The QTc is influenced by age and sex. Although alcohol intoxication is increasingly common in adolescents, there are no data on the prevalence of QTc prolongation in adolescents with alcohol intoxication. This study aimed to determine the prevalence of QTc prolongation in adolescents with alcohol intoxication and identify at-risk adolescents. In this observational study including adolescents aged 10-18 years, heart rate and QT interval were automatically assessed from an electrocardiogram (ECG) at alcohol intoxication using a validated algorithm. The QTc was calculated using both the Bazett formula (QTc_B) and Fridericia formula (QTc_F). If present, an ECG recorded within 1 year of the date of admission to the emergency department was obtained as a reference ECG. A total of 317 adolescents were included; 13.3% had a QTc_B and 7.9% a QTc_F longer than the sex- and age-specific 95th-percentile. None of the adolescents had a QTc_B or QTc_F > 500 ms, but 11.8% of the adolescents with a reference ECG had a QTc_B prolongation of > 60 ms, while no adolescents had a QTc_F prolongation of > 60 ms. QTc prolongation was mainly attributable to an increase in heart rate rather than QT prolongation, which underlies the differences between QTc_B and QTc_F. Male sex and hypokalaemia increased the likelihood of QTc prolongation.Conclusion: QTc prolongation was seen in approximately 10% of the adolescents presenting with alcohol intoxication, and although no ventricular arrhythmias were observed in this cohort, QTc prolongation increases the potential for malignant QT-related arrhythmias. Clinicians must be aware of the possibility of QTc prolongation during alcohol intoxication and make an effort to obtain an ECG at presentation, measure the QT interval, and give an adequate assessment of the findings. We advocate admitting adolescents with alcohol intoxication and QTc prolongation. During hospital admission, we recommend limiting exposure to QTc-prolonging medication, increasing potassium levels to a high-normal range (4.5-5.0 mmol/L) and obtaining a reference ECG at discharge.

[Clinical course and features of the alcohol withdrawal syndrome in a general hospital]

INTRODUCTION

Despite its frequency and high clinical burden, few studies have analyzed the clinical features of the alcohol withdrawal syndrome in a hospital setting. Our purpose was to describe its manifestations and clinical course in a general hospital.

PATIENTS AND METHODS

Patients with a diagnosis of alcohol withdrawal since January 1983 to December 2003, according to the revised fourth edition of the Diagnostic and Statistical Manual of Mental Disorders criteria, at the Xeral-Calde General Hospital in Lugo, were studied. Clinical and biochemical data at admission were collected, as well as those referred to the clinical course and complications.

RESULTS

539 episodes in 436 patients were included. Mean age was 45 (standard deviation: 12), and 91,3% were men. Abstinence was the reason for admission in 62,3%. 71,1% had a diagnosis of delirium tremens during their stay. Hallucinations were present in 59,7%, and convulsions (most of them generalized) in 41%. Patients with delirium tremens had greater elevations in temperature, heart rate and blood pressure, as well as more convulsions than minor withdrawal cases. Cirrhosis was present in 10%. The admission rate to the Intensive Care Unit (ICU) was 37,8% (95% confidence interval [95%IC]: 33,1-37,8). Of these, 69,9% needed mechanical ventilation. Mortality rate was 6,6% (95%IC: 4,2-9,1). 62% of patients died after admission in the ICU.

CONCLUSION

The majority of complications related to the alcohol withdrawal syndrome in a hospital setting develop in patients with delirium tremens. They are especially related to the rate of admissions to the ICU and the use of mechanical ventilation.

Effects of excessive ethanol consumption on the diagnosis of the metabolic syndrome using its clinical diagnostic criteria

OBJECTS

Various morbid conditions constituting the metabolic syndrome could be also caused by excessive ethanol consumption. Thus, it is conceivable that excessive ethanol consumption may affect the diagnosis of the metabolic syndrome using its current diagnostic criteria. Here, we investigated this.

MATERIALS AND METHODS

A cross-sectional study involving 2,130 Japanese man subjects aged 20 to 65 was performed.

RESULTS

The rate of subjects judged to have metabolic syndrome using its diagnostic criteria for Japanese was 15.7%. However, the prevalence was significantly higher in excessive drinkers who consume more than 20 grams of ethanol per day (n=473, 22.0%) than average drinkers (n=1,657, 13.9%, chi2=18.0, p<0.0001). The rate of subjects who satisfied each component of the criteria of the metabolic syndrome, namely that of an excessive waist circumference, hypertension, dyslipidemia, or hyperglycemia was significantly higher in the former than in the latter, respectively. When subjects with a waist circumferences of 85 cm or more were selectively studied, the prevalence of the metabolic syndrome was still higher in excessive drinkers (39.2%) than in average drinkers (32.4%, chi2=4.0, p=0.049), whereas the waist circumference was not significantly different between the two groups.

CONCLUSION

Excessive ethanol consumption is associated with an increased prevalence of the metabolic syndrome following the current clinical diagnostic criteria. Excessive ethanol consumption could simply be a factor worsening the metabolic syndrome. However, we must be aware of another possibility that excessive ethanol consumption increases the number of subjects regarded as the metabolic syndrome via mechanisms differing from visceral fat accumulation.

Hypokalaemia in alcoholic patients

Hypokalaemia is commonly found among the electrolyte abnormalities observed in chronic alcoholics. However, the underlying mechanisms of the decreased potassium levels are not well known. We undertook the present study to analyse the possible pathogenetic mechanisms of hypokalaemia in a large group of alcoholic patients (n = 127) admitted to our hospital for causes related to alcohol abuse. Serum potassium levels were significantly lower in alcoholic patients compared to the control population (3.8 + 1.1 mmol/l vs. 4.6 + 0.9 mmol/l). In 12 of these patients inappropriate kaliuresis was observed due mainly to the coexistent hypomagnesaemia. Two of the remaining four patients had a history of diarrhoea, while the other two had alcohol withdrawal syndrome with considerable respiratory alkalosis. Patients with hypokalaemia had hypomagnesaemia and respiratory alkalosis more commonly compared to the normokalaemic ones. We conclude that hypokalaemia is a relatively common electrolyte abnormality observed in alcoholic patients owing to various pathophysiological mechanisms. Among them, inappropriate kaliuresis due to the co-existent hypomagnesaemia predominates.

Serum and intracellular magnesium concentrations in intoxicated chronic alcoholic and control subjects

Serum magnesium levels may not accurately reflect overall magnesium homeostasis. To clarify the relationship between serum and intracellular magnesium concentrations in chronic alcoholism, we determined intralymphocytic magnesium levels and serum magnesium, sodium and potassium concentrations in ten chronic alcoholic subjects admitted to the emergency room during acute ethanol intoxication, and compared the results to those of 14 healthy nonalcoholic controls. Serum magnesium, sodium and potassium concentrations were within the normal range in both groups of subjects and determination of intralymphocytic magnesium levels revealed a nonsignificant decrease in alcoholic subjects compared to controls. In conclusion, serum and intralymphocytic magnesium concentrations did not differ between chronic alcoholics and controls in our population; the results of the present study do not support the practice of routine magnesium administration to chronic alcoholics in the emergency room setting.

Hemodynamic alterations in alcohol-related transitory hypertension

Alcoholic patients are often transiently hypertensive (tHT) during days 1-3 of withdrawal but become normotensive thereafter. However, at 3-4 weeks postwithdrawal these tHT patients may still show exaggerated blood pressure rises to isometric handgrip exercise. We examined the hemodynamic mechanisms associated with persistent altered pressure response. Forty-two alcoholic inpatients were equally divided into three subgroups based on admission BPs: transitory hypertensive (tHT;BP > or = 160/95 mmHg), transitory borderline hypertensive (tBH; 140/ 90 < or = BP < 160/95), and normotensive (NT; BP < 140/90). After 3-4 weeks of sobriety, the alcoholics and a normotensive nonalcoholic group (CONTs; n = 14) were tested during rest and an isometric handgrip task. Impedance cardiographic evaluation at both times showed elevated peripheral resistance, elevated heart rate, and reduced stroke volume in tHTs. Liquor consumption was found to be highly predictive of the altered hemodynamic and BP activity. Alcoholic patients with acute withdrawal hypertension (1-3 days) may show a persistent alteration of BP regulation even when resting pressures are normal.

Acetaldehyde inhibits serum aminopeptidases

Aminopeptidase A (APA)- and aminopeptidase M (APM)-like activity were assayed in Moni-Trol ES with L-alpha-aspartyl-beta-naphthylamide and L-alanyl-beta-naphthylamide, respectively. Upon preincubation of the serum with 89.4, 223.5, and 447 mM acetaldehyde at room temperature for 30 min, a reduction in 26.8%, 55.3%, and 75.8% aminopeptidase A activity was observed. Similarly, aminopeptidase M activity was reduced by 26.5% and 53.1% upon preincubation with 223.5 and 447 mM acetaldehyde. Ethanol at 84.9, 212.3, and 427.9 mM did not significantly affect the enzymic activity. Because aminopeptidase A and aminopeptidase M also degrade the pressor substance, angiotensin II, it is suggested that inhibition of aminopeptidase A- and aminopeptidase M-like activity by acetaldehyde, the product of ethanol metabolism, may lead to higher levels of circulating angiotensin II and, consequently, hypertension, in alcoholics. The hydrolysis of lysine-p-nitroanilide, an aminopeptidase B substrate, was also inhibited upon addition of acetaldehyde to Moni-Trol ES serum.

Pathogenetic mechanisms of hypomagnesemia in alcoholic patients

The aim of our study was to describe the possible pathophysiologic mechanisms of hypomagnesemia in alcoholic patients. A total of 127 chronic alcoholic patients admitted to our university hospital for causes related to alcohol abuse were studied. Hypomagnesemia was the most common electrolyte disturbance observed in 38 patients (29.9%). In 18 of them inappropriate magnesiuria was evident, possibly due to hypophosphatemia, to metabolic acidosis or to a direct magnesiuric effect of acute alcohol consumption. The causes of hypomagnesemia in the remaining 20 patients were alcohol withdrawal syndrome and diarrhea. Respiratory alkalosis was evident in 10 hypomagnesemic patients and could have played a role in the development of hypomagnesemia. A decreased magnesium intake could also have contributed to the hypomagnesemia, especially in malnourished alcoholic patients. Hypomagnesemic patients more frequently had other acid-base and electrolyte abnormalities, such as hypophosphatemia, hypokalemia, hypocalcemia, and respiratory alkalosis, as compared with the normomagnesemic patients. Moreover, in hypomagnesemic patients serum magnesium levels were correlated with the indices of potassium and phosphorus excretion, suggesting that serum magnesium levels play a central role in the homeostasis of the other electrolytes. In conclusion, hypomagnesemia is the most common electrolyte abnormality observed in alcoholic patients, as a result of various pathophysiologic mechanisms.

Magnesium supplementation prevents the development of alcohol-induced hypertension

The effect of chronic alcohol administration on blood pressure was investigated in 7-week-old Wistar rats. Tail-cuff blood pressure was significantly higher in rats who received 15% ethanol in drinking water than in control rats. Intracellular free calcium concentration of lymphocytes was increased, while magnesium concentration of erythrocyte, aorta, and skeletal muscle and erythrocyte ouabain-sensitive 22Na efflux rate constant (Kos) were decreased in alcohol-induced hypertensive rats but not in control rats. Extracellular fluid volume was also increased in alcohol-administered rats. Oral magnesium supplementation (1% MgO in rat chow) attenuated the development of alcohol-induced hypertension accompanied by increased magnesium concentration of erythrocyte, aorta, skeletal muscle, and Kos and decreased intraerythrocyte sodium concentration. Norepinephrine half-life time of the heart and spleen was also increased in magnesium-supplemented rats. Blood pressure significantly correlated positively with intracellular calcium concentration and extracellular fluid volume, negatively with magnesium concentration of erythrocyte, aorta, skeletal muscle, and Kos. These results suggest that increased intracellular calcium, which was partly due to magnesium depletion and suppressed sodium pump activity, and expanded body fluid volume had a possible role in the development of alcohol-induced hypertension. It is also suggested that oral magnesium supplementation had a hypotensive effect on alcohol-induced hypertension possibly through decreased intracellular sodium concentration caused by an activation of sodium pump and decreased sympathetic nervous activity.

Ethanol: relative fuel value and metabolic effects in vivo

A nasogastric formula infusion method was used to evaluate the steady-state fuel value of ethanol relative to that of glucose in eight chronically alcoholic men undergoing a 4- or 5-week balance experiment. Each subject received a maintenance infusion of the formula diet throughout the study. When control formula glucose (week 1) was isocalorically replaced with ethanol [week 2, 30% of kcal; week 3 or 4 (5-week experiment) 40% to 60% of kcal], the following was observed: weight loss; zero energy balance and reduced or negative balances of N, K, P, Mg, and Na; increased urinary urea N and 3-methylhistidine; lowered urinary C-peptide; no change in indirectly or directly measured thermal energy losses; and a blood level related rise in breath and urinary ethanol losses. All of these changes promptly reversed during the middle (week 3 in 5-week experiment) and final control weeks. Accounting for all diet-related energy losses (urine, breath, thermal), the fuel value of the ethanol-containing diet relative to the glucose control formula varied between 0.95 and 0.99, depending upon the blood alcohol level. Hence weight loss during short-term (seven-day) ethanol infusion is unrelated to overall negative energy balance, stems primarily from decrements in protein, minerals, and fluid, and may in part be mediated by the reduction in insulin secretion that accompanies switching from dietary glucose to ethanol.

University of California, Davis, conference: Mild hypertension

Prevalence of "higher than normal" blood pressures in a community is inversely related to the magnitude of the elevation; the milder grades of elevation are far more prevalent. A multifactorially inherited tendency to develop hypertension is modulated by multiple environmental influences. Autonomic nervous and behavioral factors plausibly appear to contribute to the initiating mechanisms of hypertension; the associated hemodynamic changes and the resulting cardiovascular structural changes interact to perpetuate the process. The complex interaction of hypertension and atherosclerosis is further complicated by direct as well as secondary effects of antihypertensive drugs on atherogenesis. Attributable cardiovascular risk is generally proportional to the degree of hypertension across the entire range of elevated blood pressure; this kind of relationship holds also for normal versus subnormal blood pressure values. Pharmacologic lowering of blood pressure, however, does not confer proportional benefit. Thus, such lowering of blood pressure to normotensive levels does not reduce the risk level to that in the normotensive population. Therapeutic outcome is influenced by the interaction of blood pressure lowering, type of antihypertensive agents used, existing risk factors, and target organ damage. Benefits of lowering blood pressure in established mild hypertension (diastolic blood pressure greater than 95 mm Hg) are confirmed. Drug treatment of patients with lower diastolic blood pressure or with isolated elevations of systolic blood pressures continues to be controversial as does the choice of initial therapeutic agent(s). The large-scale experience of clinical trials encompassing the long-term risks and benefits of the drug treatment of mild hypertension is limited to the use of diuretics and adrenergic beta blockers. A variety of new and promising therapeutic agents for use as alternate choices for initial therapy needs to undergo comparative evaluation.

Psychophysiological effects of oral ethanol in alcoholics and social drinkers

The acute and extended effects of ethanol ingestion were examined in five alcoholic subjects, and five "social" drinkers. Six physiological and four subjective report measures were taken before, during and up to 90 min after the ingestion of ethanol in three doses and placebo. Findings showed that alcohol exerted significant dose-related physiological effects in the initial minutes of ingestion, and in extended analyses of physiological and subjective measures in both groups of drinkers. Alcoholics and social drinkers generally did not differ in their physiological responses to alcohol doses and placebo, while some evidence for tolerance to reported euphoric effects of alcohol in the alcoholic subjects was found. The possibility is raised that early physiological responses observed during ethanol ingestion may arise not only from pharmacological effects of the drink, but may also be evidence for conditional predrink responses.

Hypertension-induced protein leakage in the brain in chronic ethanol administered rats

The effect of adrenalin on permeability of blood brain barrier in chronic alcohol administered rats was examined by using Evans-blue as a barrier tracer. Chronic alcohol per se did not have remarkable effect on blood-brain barrier permeability. Adrenalin administration to the chronic alcohol group caused minimal disruption in blood brain barrier. The results shown that chronic alcohol protects the blood brain barrier permeability against hypertension due to adrenalin.

Effect of ethanol on regional myocardial blood flow and hemodynamics, before and after coronary artery ligation in dogs

The effects on regional myocardial blood flows (RMBF) and hemodynamics due to ethanol administered before and after acute coronary artery ligation (CAL) in 18 anesthetized dogs were studied. Ethanol was administered to seven dogs (group I) prior to CAL and to six dogs (group II) after CAL; five dogs (group III, control) received only saline before and after CAL. Uniform blood ethanol levels (180 +/- 30 mg/dl) were maintained in groups I and II after initial ethanol administration. In these groups the heart rate and rate-pressure product (which reflects myocardial oxygen consumption) remained stable, but pulmonary arterial pressures were elevated. Other hemodynamic parameters remained stable in all groups. Ethanol caused a significant transmural increase of RMBF (p less than 0.001) in both groups I and II. In group II the increase was significant in both nonischemic and ischemic tissues, with no apparent redistribution of flow among the myocardial layers. The percentage increase of RMBF due to ethanol was highest in group II nonischemic tissue (95-107%) compared to the corresponding ischemic tissue (57-60%) and the group I myocardial tissue (36-47%) prior to CAL (p less than 0.001). The observed differences between ethanol pre- and posttreatments suggest different interactions between ethanol and catecholamines. The results also confirm that vasodilatory reserve is present in the acutely ischemic myocardium and that the local availability of ethanol is important for coronary vasodilatation.

The relationships between alcoholic beverage use and other traits to blood pressure: a new Kaiser Permanente study

In a new study controlled for many factors, we reconfirmed the relationship of higher blood pressure to alcohol use. This relationship was slightly stronger in men, whites, and persons 55 years of age or older. A slight increase in blood pressure appeared in men who drank one to two drinks daily, and a continuous increase occurred at all higher drinking levels among white men who had constant drinking habits. Among women, an increase occurred only at three or more drinks daily. The data suggest complete regression, beginning within days, of alcohol-associated hypertension upon abstinence. Blood pressure showed minor differences with beverage preference: those who preferred liquor had higher adjusted mean blood pressure than those preferring wine or beer. The results of this study contribute to the likelihood that the alcohol-blood pressure association is causal. Smoking, coffee use, and tea use showed no association with higher blood pressure. Systolic pressure showed a positive relationship to total serum calcium and an inverse relationship to serum potassium, but diastolic pressure showed little relationship to these blood constituents; the explanations include a possible direct effect on regulation of blood pressure.

Disorders of the serum electrolytes, acid-base balance, and renal function in alcoholism

This chapter reviews the disturbances of the serum sodium and potassium concentrations, acid-base imbalances, and acute renal dysfunction that are seen frequently in alcoholic patients. The hyponatremia common in decompensated cirrhotics is caused by an impairment of renal free water clearance and concomitant water ingestion. Excessive proximal renal tubular sodium reabsorption and nonosmotic vasopressin release underlie the defect in renal water excretion in cirrhosis. Restriction of water intake is the principal therapeutic measure for hyponatremia. Hypokalemia is common in alcoholics but when observed does not always represent true potassium depletion. Although most cirrhotics have a diminished total body potassium content, intracellular potassium concentration is usually normal. In some patients gastrointestinal and renal potassium losses and nutritional potassium deficiency may cause true potassium depletion. Respiratory and metabolic alkalosis are the acid-base disturbances seen most frequently in alcoholics. Acidosis is relatively uncommon and is usually due to renal insufficiency, lactic acid or keto-acid accumulation. Toxin ingestion (methanol, ethylene glycol, or isopropanol) may also cause severe acidosis. Rhabdomyolysis, common in severe alcoholism, may produce various electrolyte disturbances and acute renal failure. The prognosis for recovery is good although temporary dialysis may be necessary.

Alcohol and hypertension: implications from research for clinical practice

Despite the fact that recent epidemiological and laboratory studies appear to confirm that alcohol has an effect upon blood pressure, its impact has largely been ignored in clinical practice. This study was undertaken in an effort to answer four basic questions Is there an association between blood pressure and ethanol ingestion and if so is it causal or related to common genetic and/or environmental factors?; If an association exists, what is its likely physiological mechanism?; What additional studies are needed in order to further elucidate the relationship between alcohol and blood pressure?; What clinical recommendations, if any, are justified with our present state of knowledge?

Decreased vascular responsiveness to noradrenaline following regular ethanol consumption

Ten normal volunteers consumed 80 g of ethanol per day or abstained from ethanol for 4 consecutive days prior to measurements of blood pressure, heart rate, vascular responsiveness to noradrenaline (NA) and angiotensin II (AII) infusions and sympathetic responsiveness to isometric handgrip exercise in an open, random order, crossed study. Supine systolic and diastolic pressures and heart rates, and erect systolic pressures rose significantly following ethanol. Vascular responsiveness to NA infusions was reduced in all subjects following ethanol, while responses to AII infusions did not show a consistent pattern of change. Plasma renin activity, plasma NA and adrenaline concentrations, and concentrations of the NA metabolite 3,4 dihydroxyphenylethylene glycol (DHPG) did not significantly differ following ethanol and control treatments. The rise in plasma NA following 2 min isometric handgrip at 50% of maximal effort was greater following ethanol (0.24 +/- 0.21 nM) than control (0.12 +/- 0.10 nM) but the difference did not reach statistical significance. The pressor effect of regular ethanol consumption and the reduced vascular reactivity to NA may both be the result of an increase in sympathetic activity that was not large enough to measurably alter resting plasma NA concentrations.

Alcohol use and hypertension. Clinical considerations and implications

Alcohol abuse is a more frequent contributor to hypertension than is generally appreciated. Although hypertension is transitory in most alcoholics and may not be evident after a short period of abstinence, it is potentially dangerous. Paroxysms of hypertension might result in target-organ damage. Hypertension may be the causal link to the increased incidence of stroke and coronary heart disease observed in problem drinkers as well as a contributor to the pathogenesis of alcoholic cardiomyopathy. Because of its transitory nature, however, alcohol-associated hypertension may, regrettably , be dismissed as inconsequential. Thus, a major potential cause of cardiovascular morbidity may go untreated.