Alpha-atrial natriuretic peptide, aldosterone secretion and plasma renin activity during ethanol withdrawal: a correlation with the onset of delirium tremens?

Delirium Tremens: A Review of Clinical Studies

Delirium tremens (DT) is a severe condition resulting from alcohol withdrawal. This review highlights the challenges in diagnosing and managing DT and emphasizes the importance of early recognition and intervention to prevent complications and ensure optimal patient outcomes. The discussion of the pathophysiology of DT, focusing on the neurochemical imbalances involving the neurotransmitters gamma-aminobutyric acid and glutamate, explains how chronic alcohol dependence leads to these imbalances and contributes to the hyperexcitability seen in DT. The management of DT involves ensuring patient safety and alleviating symptoms, primarily through pharmacological approaches, such as benzodiazepines. Closely monitoring vital signs and electrolyte imbalances is necessary due to autonomic dysregulation associated with DT. The mention of the potential complexity of DT when coexisting with other conditions emphasizes the need for additional research to advance comprehension, identify predictive factors, and enhance its management.

BICORN: An R package for integrative inference of de novo cis-regulatory modules

Genome-wide transcription factor (TF) binding signal analyses reveal co-localization of TF binding sites based on inferred cis-regulatory modules (CRMs). CRMs play a key role in understanding the cooperation of multiple TFs under specific conditions. However, the functions of CRMs and their effects on nearby gene transcription are highly dynamic and context-specific and therefore are challenging to characterize. BICORN (Bayesian Inference of COoperative Regulatory Network) builds a hierarchical Bayesian model and infers context-specific CRMs based on TF-gene binding events and gene expression data for a particular cell type. BICORN automatically searches for a list of candidate CRMs based on the input TF bindings at regulatory regions associated with genes of interest. Applying Gibbs sampling, BICORN iteratively estimates model parameters of CRMs, TF activities, and corresponding regulation on gene transcription, which it models as a sparse network of functional CRMs regulating target genes. The BICORN package is implemented in R (version 3.4 or later) and is publicly available on the CRAN server at https://cran.r-project.org/web/packages/BICORN/index.html.

Ethanol Withdrawal Alters the Oxidative State of the Heart Through AT1-Dependent Mechanisms

Aims

We investigated the cardiac effects of ethanol withdrawal and the possible role of AT1 receptors in such response.

Methods

Male Wistar rats were treated with increasing doses of ethanol (3 to 9%, vol./vol.) for 21 days. The cardiac effects of ethanol withdrawal were investigated 48 h after abrupt discontinuation of ethanol. Some animals were orally treated with losartan (10 mg/kg/day), a selective AT1 receptor antagonist.

Results

Ethanol withdrawal did not affect serum levels of creatine kinase (CK)-MB. Losartan prevented ethanol withdrawal-induced increase in superoxide anion (O2•−) production in the left ventricle (LV). However, ethanol withdrawal did no alter the levels of thiobarbituric acid reactive substances (TBARS) or the expression of Nox1, Nox2 or Nox4 were found in the LV. Ethanol withdrawal reduced the concentration of hydrogen peroxide (H2O2) in the LV and this response was prevented by losartan. Ethanol withdrawal increased catalase activity in the LV and losartan attenuated this response. No changes on superoxide dismutase (SOD) activity or expression were detected in the LV during ethanol withdrawal. The expression of AT1, AT2 or angiotensin converting enzyme (ACE) was not affected by ethanol withdrawal. Similarly, no changes on the expression of ERK1/2, SAPK/JNK, COX-1 or COX-2 were found in the LV during ethanol withdrawal.

Conclusions

Ethanol withdrawal altered the cardiac oxidative state through AT1-dependent mechanisms. Our findings showed a role for angiotensin II/AT1 receptors in the initial steps of the cardiac effects induced by ethanol withdrawal.

A relationship between the aldosterone-mineralocorticoid receptor pathway and alcohol drinking: preliminary translational findings across rats, monkeys and humans

Aldosterone regulates electrolyte and fluid homeostasis through binding to the mineralocorticoid receptors (MRs). Previous work provides evidence for a role of aldosterone in alcohol use disorders (AUDs). We tested the hypothesis that high functional activity of the mineralocorticoid endocrine pathway contributes to vulnerability for AUDs. In Study 1, we investigated the relationship between plasma aldosterone levels, ethanol self-administration and the expression of CYP11B2 and MR (NR3C2) genes in the prefrontal cortex area (PFC) and central nucleus of the amygdala (CeA) in monkeys. Aldosterone significantly increased after 6- and 12-month ethanol self-administration. NR3C2 expression in the CeA was negatively correlated to average ethanol intake during the 12 months. In Study 2, we measured Nr3c2 mRNA levels in the PFC and CeA of dependent and nondependent rats and the correlates with ethanol drinking during acute withdrawal. Low Nr3c2 expression levels in the CeA were significantly associated with increased anxiety-like behavior and compulsive-like drinking in dependent rats. In Study 3, the relationship between plasma aldosterone levels, alcohol drinking and craving was investigated in alcohol-dependent patients. Non-abstinent patients had significantly higher aldosterone levels than abstinent patients. Aldosterone levels positively correlated with the number of drinks consumed, craving and anxiety scores. These findings support a relationship between ethanol drinking and the aldosterone/MR pathway in three different species.

Ethanol withdrawal increases oxidative stress and reduces nitric oxide bioavailability in the vasculature of rats

We analyzed the effects of ethanol withdrawal on the vascular and systemic renin-angiotensin system (RAS) and vascular oxidative stress. Male Wistar rats were treated with ethanol 3-9% (v/v) for a period of 21 days. Ethanol withdrawal was induced by abrupt discontinuation of the treatment. Experiments were performed 48 h after ethanol discontinuation. Rats from the ethanol withdrawal group showed decreased exploration of the open arms of the elevated-plus maze (EPM) and increased plasma corticosterone levels. Ethanol withdrawal significantly increased systolic blood pressure and plasma angiotensin II (ANG II) levels without an effect on plasma renin activity (PRA), angiotensin converting enzyme (ACE) activity, or plasma angiotensin I (ANG I) levels. No differences in vascular ANG I, ANG II levels, and ACE activity/expression and AT1 and AT2 receptor expression were detected among the experimental groups. Plasma osmolality, as well as plasma sodium, potassium, and glucose levels were not affected by ethanol withdrawal. Ethanol withdrawal induced systemic and vascular oxidative stress, as evidenced by increased plasma thiobarbituric acid-reacting substances (TBARS) levels and the vascular generation of superoxide anion. Ethanol withdrawal significantly decreased plasma and vascular nitrate/nitrite levels. Major new findings of the present study are that ethanol withdrawal induces vascular oxidative stress and reduces nitric oxide (NO) levels in the vasculature. Additionally, our study provides novel evidence that ethanol withdrawal does not affect the vascular ANG II generating system while stimulating systemic RAS. These responses could predispose individuals to the development of cardiovascular diseases.

Risk factors for lethal outcome in patients with delirium tremens - psychiatrist's perspective: a nested case-control study

BACKGROUND

The aim was to identify potential risk factors for lethal outcome in patients with delirium tremens (DT) treated in the psychiatric setting.

METHODS

In a nested case-control study, a total of 190 medical records of patients with DT hospitalized at the Psychiatric Clinic in Serbia between 2002 and 2011 were reviewed and analyzed. The characteristics of patients who died (cases) were compared with those who survived (controls). For each case, two controls (matched for age, gender, and year of hospitalization) were randomly chosen.

RESULTS

Significant differences between cases and controls were found for serum potassium levels (p < 0.001), the number of hospitalizations (p < 0.001), and duration of hospitalization (p < 0.001). A significant association with lethal outcome was found for serum potassium levels even in the normal range (adjusted odds ratio 40.52; 95% CI 1.20, >1,000.00; p = 0.004).

CONCLUSIONS

Even though the number and duration of psychiatric hospitalizations were identified as factors determining survival after admission for DT, only serum potassium levels were found to be significant. Patients with an increase in potassium (or absence of hypokalemia) may require more intensive treatment. Monitoring of serum levels of potassium is important not only as an indicator for replacement but also as an indicator of maladaptation.

To live alone and to be depressed, an alarming combination for the renin-angiotensin-aldosterone-system (RAAS)

INTRODUCTION

The renin-angiotensin-aldosterone-system (RAAS) is one of the most important systems involved in the pathogenesis of cardiovascular diseases. Its role in stress response has been generally neglected, although the progression of cardiovascular disease is considerably increased in the presence of stress and especially in the presence of depression risk. With the present analysis we aimed to evaluate whether the activity of the RAAS correlates with depressive symptomatology and with chronic stress. Moreover, we aimed to analyse whether stress response is altered in the presence of depressed symptomatology. We chose "living alone" to be our paradigm of chronic stress.

METHODS AND RESULTS

Aldosterone and renin levels were assessed in 1743 (829 men, 914 women) from the population-based KORA study (Cooperative Health Research in the Region of Augsburg). The relationship between aldosterone, renin levels and the different combinations of living alone and depressive symptomatology was examined in three different multiple linear regression models adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and bio-behavioural factors. Neither "living alone" nor depressive symptomatology alone were associated with an activation of the RAAS, but the combination of living alone and depressive symptomatology yielded a highly significant increase in the aldosterone (p<0.01) and renin level (p=0.03).

CONCLUSION

Our findings show that depressive symptomatology is associated with a hyper-responsiveness to chronic stress. Under the condition of chronic stress depressed individuals have an activated RAAS. Activation of the RAAS might explain the known increased risk of negative cardiovascular disease outcomes in this group.

Persistent alterations of vasopressin and N-terminal proatrial natriuretic peptide plasma levels in long-term abstinent alcoholics

BACKGROUND

During alcohol withdrawal and early abstinence, severe alterations of electrolyte and water homeostasis and their regulating hormones are well recognized. Almost nothing is known about regeneration of these functions with long-term abstinence. This cohort study was designed to monitor determinants of electrolyte and water balance over 280 days of abstinence in alcohol-dependent men compared with healthy controls.

METHODS

Vasopressin (AVP), N-terminal proatrial natriuretic peptide, aldosterone, angiotensin II, and electrolytes, together with major parameters of kidney and liver function, were monitored in 35 male alcoholics aged 44 +/- 8 years. Of these, 21 could be followed up to 280 days of strictly controlled abstinence due to their participation in the Outpatient Long-Term Intensive Therapy for Alcoholics. The control group comprised 20 healthy male volunteers aged 39 +/- 7 years.

RESULTS

Basal AVP levels were found to be suppressed over the whole study period. In contrast, N-terminal proatrial natriuretic peptide remained increased over all 280 days. No persistent alterations were found for aldosterone or angiotensin II. Sodium and potassium in plasma and urine returned to normal within a few weeks. Creatinine clearance, urea nitrogen in plasma and urine, urinary osmolality, hematocrit, and hemoglobin remained low as compared with controls over the entire study.

CONCLUSIONS

Chronic alcohol abuse causes severe and persistent alterations in the hormonal regulatory systems of electrolyte and water balance. The suppressed basal secretion of AVP may reflect a dysregulation in the brain that influences the hypothalamic-pituitary-adrenal axis function, mood, memory, addiction behavior, and craving during alcohol abstinence. These findings may provide a ground for future therapeutic approaches to stable abstinence.

Risk for delirium tremens in patients with alcohol withdrawal syndrome

To determine the characteristics associated with an increased risk for delirium tremens (DT) we performed a case-control study at the detoxification units of two hospitals. Cases met DSM-IV criteria for DT. For each case (n = 15), 3 controls (n = 45) were chosen. Eligibility criteria were applied equally to cases and controls. Cases were more likely than controls to report a prior complicated withdrawal (DT or alcohol withdrawal seizure) (53 vs. 27%, OR 3.1, 95% CI 0.94-10.55), have a systolic blood pressure greater than 145 mm Hg on admission (60 vs. 27%, OR 4.1, 95% CI 1.21-14.06), and have comorbidity scores of at least 1 (60 vs. 18%, OR 6.9, 95% CI 1.92-25.08). Zero cases (0%) and 15 (33%) controls had no prior complicated withdrawals and no adverse clinical features (systolic blood pressure >145 or comorbidity score >1). Compared to this group, the odds of being a case and having both prior complicated withdrawal and at least 1 adverse clinical feature was 44.8 (95% CI 4.36-460). Elevated blood pressure, prior complicated alcohol withdrawal and medical comorbidity, alone and in combination, are associated with an increased risk of delirium tremens.

Involvement of plasma atrial natriuretic peptide in protracted alcohol withdrawal

OBJECTIVE

Atrial natriuretic peptide (ANP) has been shown to inhibit the effects of corticotrophin releasing hormone, corticotrophin and cortisol, and to influence affective and anxiety symptoms in man. We tested the hypothesis of whether ANP is associated with endocrine and psychopathological disturbances during acute alcohol withdrawal.

METHOD

ANP and cortisol plasma concentrations were studied in alcoholics during in-patient detoxification and in healthy controls. Additionally, craving, depressive mood and anxiety were assessed.

RESULTS

Although mean ANP levels increased significantly in alcoholics between days 1 and 14, they remained diminished compared to controls. Separating a subgroup of alcoholics with a decrease of ANP levels during withdrawal, these individuals revealed significantly elevated scores for mean and maximum craving and a trend to an elevated self-rated anxiety on day 14.

CONCLUSION

We suggest that a dysregulation of ANP plasma levels during alcohol withdrawal may contribute to symptoms of protracted withdrawal such as craving and anxiety.

The role of atrial natriuretic peptide in alcohol withdrawal: a peripheral indicator and central modulator?

Changes in fluid and electrolyte homeostasis may accompany and are likely to modify the clinical symptoms of alcohol-withdrawal reactions. It was of obvious theoretical and practical interest therefore to investigate the changes in the secretion of hormones, which regulate the fluid and electrolyte homeostasis (atrial natriuretic peptide, aldosterone and plasma renin activity) during alcohol withdrawal in chronic alcoholic patients. In a phase of severe withdrawal, there were increased plasma renin activity and aldosterone levels observed. In a phase of partial recovery, on the other hand, the elevated plasma renin activity and aldosterone levels were back to the normal range. In 60% of the patients, delirium tremens was gradually developing during the observation period. In these patients, an elevated level of atrial natriuretic peptide was observed at the time of hospital admission, i.e. days before the actual onset of delirium tremens. It is concluded that the disturbed volume homeostasis and the consequently altered plasma atrial natriuretic peptide secretion might be associated with, and therefore used as an indicator of the onset of delirium tremens. To study the role of central nervous atrial natriuretic peptide, mice were rendered tolerant to and dependent on alcohol with an alcohol-liquid diet for 14 days. Five hours after withdrawal from alcohol, withdrawal hyperexcitability symptoms were analyzed. Intracerebroventricular (i.c.v.) injection of atrial natriuretic peptide attenuated, whereas that of an antiserum against atrial natriuretic peptide intensified the severity of handling-induced convulsions. N-methyl-D-aspartate induced behavioral seizures in a dose-dependent manner, whose effect was more intensive during the alcohol-withdrawal period than in alcohol-naive animals. I.c.v. injections of atrial natriuretic peptide dose-dependently inhibited, whereas that of antiserum against atrial natriuretic peptide potentiated the seizure-inducing effect of N-methyl-D-aspartate in alcohol-dependent mice. Although tentatively, it is concluded that peripheral secretion of atrial natriuretic peptide may be an indicator, whereas central nervous atrial natriuretic peptide a neuropeptide modulator of alcohol-withdrawal symptomatology.

Atrial natriuretic peptide modulates N-methyl-D-aspartate-induced hyperexcitability in ethanol-dependent mice

The role of central nervous atrial natriuretic peptide was investigated for behavioral hyperexcitability in alcohol-dependent mice. Mice were made tolerant to and dependent on ethanol with an ethanol-liquid diet for 14 days. Five hours after withdrawal from ethanol, withdrawal symptoms were analyzed by scoring handling-induced convulsions. N-methyl-D-aspartate (NMDA) induced behavioral seizures in a dose-dependent manner, an effect which was more intensive during the ethanol withdrawal period than in alcohol-naive animals. Intracerebroventricular (i.c.v.) injections of alpha-atrial natriuretic peptide (atrial natriuretic peptide) dose-dependently inhibited, whereas injection of an antiserum against atrial natriuretic peptide potentiated, the seizure-inducing effect of NMDA in ethanol-dependent mice. The main conclusion is that central nervous atrial natriuretic peptide plays a modulatory role in behavioral hyperexcitability during alcohol withdrawal.

Sodium sensitivity of blood pressure in long-term detoxified alcoholics

To investigate whether sodium sensitivity of blood pressure participates in the relationship of arterial hypertension to chronic alcohol consumption, 30 alcoholics detoxified from 6 to 12 months and 30 teetotaler controls underwent a dietary sodium manipulation study. They received a daily 55 mmol sodium diet for 7 days, followed by a 260 mmol sodium diet for 7 days. Changes in 24-hour urinary sodium excretion between the end of each period were similar in alcoholics and controls (202+/-16 SEM mmol and 227+/-11, respectively). Plasma renin activity in alcoholics was lower than in controls at both low (2.4+/-0.4 ng angiotensin I/mLxh(-1) versus 3. 7+/-0.2, P<0.003) and high sodium intake (0.47+/-0.10 versus 0. 82+/-0.10, P<0.05), with smaller variations in alcoholics (-1.9+/-0. 3 versus -2.9+/-0.2, P<0.009). In alcoholics, alteration in sodium intake was followed by greater changes in both systolic and mean blood pressure (ambulatory blood pressure monitoring), which rose by 10.6+/-2.2 mm Hg and 7.3+/-1.5 versus 4.7+/-1.4 and 3.9+/-1.0 in controls, respectively (P<0.03 for systolic and P<0.05 for mean blood pressure). The ratio of changes in mean blood pressure to those in 24-hour urinary sodium excretion was higher in alcoholics (0.044+/- 0.011 mm Hgxmmol(-1) versus 0.018+/-0.0041, P<0.005). Our data show that in detoxified alcoholics, there is an abnormal response of both blood pressure and plasma renin activity to variations in salt intake similar to that in sodium-sensitive arterial hypertension. The precise relationship between the sodium sensitivity of blood pressure in detoxified alcoholics and the long-term influence of alcohol on blood pressure remains to be elucidated.

Pharmacotherapies for alcohol abuse. Withdrawal and treatment

Pharmacologic management of alcoholism is only one part of the management of both alcohol dependence and withdrawal, which also includes the provision of a calm, quiet environment; reassurance; ongoing reassessment; attention to fluid and electrolyte disorders; treatment of coexisting addictions and common medical, surgical, and psychiatric comorbidities; and referral for ongoing psychosocial and medical treatment. For further discussion of these topics, the reader is referred to previously published sources. A survey of alcoholism treatment programs revealed that although benzodiazepines were the most commonly used drugs, standardized monitoring of patients' withdrawal severity was not common practice, and a significant minority of clinicians were using a variety of other drugs, some not known to prevent or treat the complications of withdrawal. Treatment should be based on the available evidence (Working Group on Pharmacological Management of Alcohol Withdrawal: American Society of Addiction Medicine Committee on Practice Guidelines: Pharmacological management of alcohol withdrawal: An evidence-based practice guideline. Unpublished draft, 1997). Patients with significant symptoms, patients with complications such as seizures or delirium tremens, and patients at higher risk for complications of alcohol withdrawal should receive benzodiazepines, particularly chlordiazepoxide, diazepam, or lorazepam, because of their safety and documented efficacy in preventing and treating the most serious complications of alcohol withdrawal. These drugs may be dosed on a fixed schedule for a predetermined number of doses on a tapering schedule over several days, or they may be administered by front-loading. An alternative approach for selected patients without seizures or acute comorbidity is symptom-triggered therapy, which individualizes treatment and decreases the duration and dose of medication administration. With either of the regimens, patients should have their withdrawal severity monitored until symptoms are resolving. Once withdrawal from alcohol is safely completed, the focus should turn to helping to prevent relapse. Disulfiram may be useful in highly motivated subsets of patients and when compliance-enhancing strategies are used. Naltrexone is useful in the broader population of patients entering treatment for alcohol dependence. These pharmacologic interventions should be given in the context of ongoing psychosocial support. There is substantial evidence that pharmacologic management of alcohol abuse and dependence is effective. As would be predicted from alcohol's myriad cellular effects, no panacea exists for alcoholism. For alcohol withdrawal, however, although treatment regimens have only recently been refined, evidence for effective treatment of symptoms and prevention of complications with benzodiazepines has been available for decades. Within the last decade, effective treatments, including naltrexone, have been shown to reduce alcohol intake in alcohol-dependent persons. Given the prevalence and cost of alcohol-related problems, all effective therapies (including pharmacologic treatments) should be considered to treat alcohol abuse and dependence.

Chronic ethanol ingestion modifies the renin-aldosterone axis independent of alterations in the regulation of atrial natriuretic peptide

Using an animal model, we have investigated the effects of chronic ethanol ingestion on the regulation of atrial natriuretic peptide (ANP) synthesis and release. Male Sprague-Dawley rats were maintained for 6 weeks on a liquid diet of ethanol (up to 20% v/v) as part of a 2% solution of calf milk replacer. Weight-matched controls received an equal volume of ethanol-free solution, and normal animals drank ad libitum. All animals received rat chow throughout the experiment. This model produced physiologically relevant levels of blood ethanol, as concentrations at the time of sacrifice were 171.98 +/- 39.26 mg/dl. Plasma renin activity was significantly elevated in response to ethanol treatment, whereas circulating aldosterone concentration was reduced. No alterations in the plasma or atrial tissue levels of ANP were evident, although we did observe a significant increase in the ventricular tissue levels of ANP from 45.1 to 71.8 ng/g as a consequence of ethanol treatment. Levels of both atrial and ventricular ANP mRNA were not different between alcohol-treated and liquid-restricted control animals, although both groups showed significant increases in the amount of transcript in comparison with rats drinking ad libitum. No significant increases in either arterial blood pressure or heart/body weight ratio were observed for ethanol-treated rats. These results suggest that modifications in the renin-aldosterone axis can occur independently of alterations in the regulation of ANP under the influence of chronic ethanol ingestion.

Alpha-atrial natriuretic peptide attenuates ethanol withdrawal symptoms

Mice were rendered tolerant to and dependent on ethanol with an ethanol-liquid diet for 14 days. Five hours after withdrawal from ethanol, withdrawal symptoms were analyzed by scoring handling-induced convulsions. Intracerebroventricular (i.c.v.) injection of alpha-atrial natriuretic peptide (alpha-ANP) attenuated, whereas that of an antiserum against alpha-ANP (anti-ANP) intensified the severity of handling-induced convulsions.

Acute ethanol ingestion modifies the circulating plasma levels of atrial natriuretic peptide

Since ethanol ingestion is associated with a disruption of water and electrolyte balance in a variety of species, we sought to evaluate the regulatory control of atrial natriuretic peptide (ANP) in response to acute doses of ethanol. Male Sprague-Dawley rats were administered a 5-g/kg dose of ethanol (40% w/v) via a gastric tube, while control animals received an equivalent volume of water. Expressed as a percentage of control, plasma ANP levels were 39.0%, 28.5%, and 23.6% in the ethanol-treated animals at 30, 60, and 120 min postintubation, respectively. Ethanol-treated animals displayed blood alcohol concentrations of 89.0, 137.6, and 214.1 mg/dl at the same time periods. After 120 min, plasma renin activity was elevated from 8.7 to 20.3 ng/ml/h in conjunction with an increase in the levels of circulating aldosterone from 16.3 to 42.5 ng/dl and an increase in plasma vasopressin from 2.2 to 3.6 pg/ml. Levels of atrial ANP mRNA remained consistent over the time course of the experiment, and no changes in the amount of ventricular ANP transcript were observed. Tissue ANP levels were similar between ethanol-treated and water-loaded control animals. In vitro experiments using cultured cardiac myocytes suggest that ethanol exposure may not directly affect ANP secretion. We propose that acute ethanol treatment may inhibit atrial distension and subsequently modify the control of ANP release under volume loading conditions.