Adrenocorticotropic Hormone/Cortisol Response to Physical Exercise in Abstinent Alcoholic Patients

The physiological responses to acute stress in alcohol-dependent patients: A systematic review

Dysregulation of physiological stress reactivity plays a key role in the development and relapse risk of alcohol dependence. This article reviews studies investigating physiological responses to experimentally induced acute stress in patients with alcohol dependence. A systematic search from electronic databases resulted in 3641 articles found and after screening 62 articles were included in our review. Studies are analyzed based on stress types (i.e., social stress tasks and nonsocial stress tasks) and physiological markers (i.e., the nervous system, the endocrine system, somatic responses and the immune system). In studies applying nonsocial stress tasks, alcohol-dependent patients were reported to show a blunted stress response compared with healthy controls in the majority of studies applying markers of adrenocorticotropic hormone and cortisol. In studies applying social stress tasks, findings are inconsistent, with less than half of the studies reporting altered physiological stress responses in patients. We discuss the impact of duration of abstinence, comorbidities, baseline physiological arousal and intervention on the discrepancy of study findings. Furthermore, we review evidence for an association between blunted physiological stress responses and the relapse risk among patients with alcohol dependence.

Chronic alcohol disrupts hypothalamic responses to stress by modifying CRF and NMDA receptor function

The chronic inability of alcoholics to effectively cope with relapse-inducing stressors has been linked to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and corticotropin-releasing factor (CRF) signaling. However, the cellular mechanisms responsible for this dysregulation are yet to be identified. After exposure of male Sprague Dawley rats to chronic intermittent ethanol (CIE; 5-6 g/kg orally for 35 doses over 50 days) or water, followed by 40-60 days of protracted withdrawal, we investigated CIE effects on glutamatergic synaptic transmission, stress-induced plasticity, CRF- and ethanol-induced NMDAR inhibition using electrophysiological recordings in parvocellular neurosecretory cells (PNCs) of the paraventricular nucleus. We also assessed CIE effects on hypothalamic mRNA expression of CRF-related genes using real-time polymerase chain reaction, and on HPA axis function by measuring stress-induced increases in plasma adrenocorticotropic hormone, corticosterone, and self-grooming. In control rats, ethanol-mediated inhibition of NMDARs was prevented by CRF1 receptor (CRFR1) blockade with antalarmin, while CRF/CRFR1-mediated NMDAR blockade was prevented by intracellularly-applied inhibitor of phosphatases PP1/PP2A, okadaic acid, but not the selective striatal-enriched tyrosine protein phosphatase inhibitor, TC-2153. CIE exposure increased GluN2B subunit-dependent NMDAR function of PNCs. This was associated with the loss of both ethanol- and CRF-mediated NMDAR inhibition, and loss of stress-induced short-term potentiation of glutamatergic synaptic inputs, which could be reversed by intracellular blockade of NMDARs with MK801. CIE exposure also blunted the hormonal and self-grooming behavioral responses to repeated restraint stress. These findings suggest a cellular mechanism whereby chronic alcohol dysregulates the hormonal and behavioral responses to repetitive stressors by increasing NMDAR function and decreasing CRFR1 function.

Is Exercise a Useful Intervention in the Treatment of Alcohol Use Disorder? Systematic Review and Meta-Analysis

OBJECTIVES

This systematic review and meta-analysis examined the effects of exercise on individuals with alcohol use disorders (AUDs) across multiple health outcomes.

DATA SOURCES

PubMed, Medline, Web of Science, Scopus, Academic Search complete, Sport Discuss, and ERIC databases.

STUDY INCLUSION AND EXCLUSION CRITERIA

Interventional studies published between 2000 and 2018 focused on evaluating the effectiveness of exercise interventions in adults with AUD.

DATA EXTRACTION

This protocol was prepared using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocols standard and the Meta-Analyses and Systematic Reviews of Observational Studies guidelines.

DATA SYNTHESIS

Physical activity levels/fitness [VO₂ max (Oxygen Uptake) and HRmax (Maximum Heart Rate)], levels of depression, anxiety, self-efficacy, quality of life, and alcohol consumption (number of standard drinks consumed per day and per week).

RESULTS

The findings indicated that exercise significantly improved physical fitness as assessed by VO₂ max (standardized mean difference [SMD]: 0.487, P < .05) and HRmax (SMD: 0.717, P < .05). Similarly, exercise significantly improved mental health as assessed by quality of life (SMD: 0.425, P < .05), but levels of depression, anxiety, self-efficacy, and alcohol consumption did not change significantly. Aerobic exercise alleviated depression and anxiety symptoms more than that of yoga and mixed types. Duration of exercise also had a similar effect on anxiety and depression.

CONCLUSIONS

Exercise can be an effective and persistent adjunctive treatment for individuals with AUDs.

Abstinence from alcohol consumption and exercise capacity: A pre and post intervention cohort study

The benefits or harm associated with moderate levels of alcohol consumption on cardiorespiratory fitness are unclear. We hypothesised that in moderate drinkers, four weeks of abstinence could improve cardiorespiratory fitness. This was a single centre, prospective, pre and post intervention, experimental cohort study. Participants were recruited from healthy volunteers among hospital staff, who were non-smokers, over 25 years of age and regularly consumed ≥3 units of alcohol a day, ≥4 times a week for > 1 month. Cardiopulmonary exercise test was used to provide objective, quantifiable and reproducible data. In all, 30 participated, and data were analysed for 22 participants. Mean (SD) peak oxygen consumption and oxygen consumption at anaerobic threshold were similar before and after alcohol abstinence: 37.55 (10.89) and 39.66 (11.48) (P = 0.21) and 18.52 (5.43) and 16.82 (5.19) ml/kg/min (P = 0.1), respectively. It is concluded that this preliminary study did not establish a correlation between four weeks alcohol abstinence and cardiopulmonary fitness as measured by cardiopulmonary exercise test, among healthy volunteers self-reporting moderate alcohol consumption.

On the Run for Hippocampal Plasticity

Accumulating research in rodents and humans indicates that exercise benefits brain function and may prevent or delay onset of neurodegenerative conditions. In particular, exercise modifies the structure and function of the hippocampus, a brain area important for learning and memory. This review addresses the central and peripheral mechanisms underlying the beneficial effects of exercise on the hippocampus. We focus on running-induced changes in adult hippocampal neurogenesis, neural circuitry, neurotrophins, synaptic plasticity, neurotransmitters, and vasculature. The role of peripheral factors in hippocampal plasticity is also highlighted. We discuss recent evidence that systemic factors released from peripheral organs such as muscle (myokines), liver (hepatokines), and adipose tissue (adipokines) during exercise contribute to hippocampal neurotrophin and neurogenesis levels, and memory function. A comprehensive understanding of the body-brain axis is needed to elucidate how exercise improves hippocampal plasticity and cognition.

Exercise as treatment for alcohol use disorders: systematic review and meta-analysis

OBJECTIVES

To conduct a systematic review and meta-analysis investigating effects of exercise for people with alcohol use disorders (AUDs) across multiple health outcomes. We also investigated the prevalence and predictors of dropout from exercise studies in AUDs.

DESIGN

Systematic review and random effects meta-analysis with meta-regression analyses.

DATA SOURCES

3 major electronic databases were searched from inception until April 2016 for exercise intervention studies in adults with AUDs.

ELIGIBILITY CRITERIA

Studies of acute exercise in people with AUDs; and randomised and non-randomised trials examining effects of long-term (≥2 weeks) exercise.

RESULTS

21 studies and 1204 unique persons with AUDs (mean age 37.8 years, mean illness duration 4.4 years) were included. Exercise did not reduce daily alcohol consumption (standardised mean difference (SMD) =-0.886, p=0.24), or the Alcohol Use Disorders Identification Test (AUDIT) total scores (SMD=-0.378, p=0.18). For weekly consumption (n=3 studies), a statistically significant difference was observed favouring exercise (SMD=-0.656, p=0.04), but not after adjustment for publication bias (SMD=-0.16, 95% CI -0.88 to 0.55). Exercise significantly reduced depressive symptoms versus control (randomised controlled trials (RCTs) =4; SMD=-0.867, p=0.006, I²=63%) and improved physical fitness (VO₂) (RCTs=3; SMD=0.564, p=0.01, I²=46%). The pooled dropout rate was 40.3% (95% CI 23.3% to 60.1%) which was no different to control conditions (OR=0.73, p=0.52). Dropouts were higher among men (β=0.0622, p<0.0001, R²=0.82).

LIMITATIONS

It was not possible to investigate moderating effects of smoking.

CONCLUSIONS

Available evidence indicates exercise appears not to reduce alcohol consumption, but has significant improvements in other health outcomes, including depression and physical fitness. Additional long-term controlled studies of exercise for AUDs are required.

Role of exercise in the treatment of alcohol use disorders

Excessive alcohol use can cause harmful effects on the human body, which are associated with serious health problems, and it can also lead to the development of alcohol use disorders (AUDs). There is certain evidence that physical exercise positively affects excessive alcohol use and the associated problems by leading to reduced alcohol intake. A literature search was conducted using the databases PubMed, Medline and Web of Science. The search terms used as keywords were: Addiction, abuse, alcohol use disorders, exercise training, β-endorphin, opioids, brain, ethanol and alcohol. The current study presents the studies that reported on the use of exercise in the treatment of AUDs between 1970 and 2015. The potential psychological and physiological mechanisms that contribute to the action of exercise were also reviewed, highlighting the role of β-endorphin and the hypothalamic-pituitary-adrenal axis in AUDs and the possible association among physical activity, the endogenous opioid system and the desire for alcohol. Only 11 studies were identified that refer to the effect of exercise on alcohol consumption and/or the associated outcomes. Six of those studies concluded that exercise may have a positive impact towards alcohol consumption, abstinence rates or the urge to drink. One of those studies also indicated that a bout of exercise affects the endogenous opioids, which may be associated with the urge to drink. Another 3 studies indicated that responses to acute exercise in individuals with AUDs are different compared to those in healthy ones. Generally, despite limited research data and often contradictory results, there is certain early promising evidence for the role of exercise as an adjunctive tool in the treatment of AUDs. Physiological and biochemical parameters that would confirm that exercise is safe for individuals with AUDs should be examined in future studies.

Stress and the HPA axis: role of glucocorticoids in alcohol dependence

Stress has long been suggested to be an important correlate of uncontrolled drinking and relapse. An important hormonal response system to stress-the hypothalamic-pituitary-adrenal (HPA) axis-may be involved in this process, particularly stress hormones known as glucocorticoids and primarily cortisol. The actions of this hormone system normally are tightly regulated to ensure that the body can respond quickly to stressful events and return to a normal state just as rapidly. The main determinants of HPA axis activity are genetic background, early-life environment, and current life stress. Alterations in HPA axis regulation are associated with problematic alcohol use and dependence; however, the nature of this dysregulation appears to vary with respect to stage of alcohol dependence. Much of this research has focused specifically on the role of cortisol in the risk for, development of, and relapse to chronic alcohol use. These studies found that cortisol can interact with the brain's reward system, which may contribute to alcohol's reinforcing effects. Cortisol also can influence a person's cognitive processes, promoting habit-based learning, which may contribute to habit formation and risk of relapse. Finally, cortisol levels during abstinence may be useful clinical indicators of relapse vulnerability in alcohol-dependent people.

Serum NPY and BNDF response to a behavioral stressor in alcohol-dependent and healthy control participants

RATIONALE

Neuropeptide Y (NPY) and brain-derived neurotrophic factor (BDNF) have been implicated in both the stress response and alcohol addiction. However, few studies have assessed the NPY and BDNF response to stress in alcohol-dependent participants and the concurrent measure of NPY and BDNF has not been reported in human participants.

OBJECTIVE

The purpose of this study was to concurrently assess serum NPY and BDNF, as well as adrenocorticotropin (ACTH) and cortisol, in control and race- and aged-matched abstinent alcohol-dependent participants in response to a stress-inducing public-speaking task.

METHODS

Basal and post-stress serum values of NPY and BDNF, as well as ACTH and cortisol, were assessed in 14 abstinent alcohol-dependent and ten healthy control male participants.

RESULTS

Basal measures were stable over short periods of time and stress induced a significant increase in both NPY (p = 0.002) and BDNF (p = 0.006) as well as ACTH (p < 0.001) and cortisol (p < 0.007). Alcohol-dependent and control groups did not significantly differ on any basal or stress-induced measure. Basal and delta responses of NPY and BDNF were not significantly correlated, and delta peak responses of NPY and BDNF did not correlate with one another or with their respective ACTH and cortisol responses.

CONCLUSIONS

These findings reveal that both serum NPY and BDNF are responsive to behavioral stressors, although their regulatory mechanisms appear to differ from one another and those of the hypothalamic-pituitary-adrenal axis. Differences in basal and stress-induced responses of NPY and BDNF were not supported between control and abstinent alcohol-dependent subjects.

Effects of adrenal sensitivity, stress- and cue-induced craving, and anxiety on subsequent alcohol relapse and treatment outcomes

CONTEXT

Alcoholism is a chronic, relapsing illness in which stress and alcohol cues contribute significantly to relapse risk. Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, increased anxiety, and high alcohol craving have been documented during early alcohol recovery, but their influence on relapse risk has not been well studied.

OBJECTIVES

To investigate these responses in treatment-engaged, 1-month-abstinent, recovering alcohol-dependent patients relative to matched controls (study 1) and to assess whether HPA axis function, anxiety, and craving responses are predictive of subsequent alcohol relapse and treatment outcome (study 2).

DESIGN

Experimental exposure to stress, alcohol cues, and neutral, relaxing context to provoke alcohol craving, anxiety, and HPA axis responses (corticotropin and cortisol levels and cortisol to corticotropin ratio) and a prospective 90-day follow-up outcome design to assess alcohol relapse and aftercare treatment outcomes.

SETTING

Inpatient treatment in a community mental health center and hospital-based research unit.

PARTICIPANTS

Treatment-engaged alcohol-dependent individuals and healthy controls.

MAIN OUTCOME MEASURES

Time to alcohol relapse and to heavy drinking relapse.

RESULTS

Significant HPA axis dysregulation, marked by higher basal corticotropin level and lack of stress- and cue-induced corticotropin and cortisol responses, higher anxiety, and greater stress- and cue-induced alcohol craving, was seen in the alcohol-dependent patients vs the control group. Stress- and cue-induced anxiety and stress-induced alcohol craving were associated with fewer days in aftercare alcohol treatment. High provoked alcohol craving to both stress and to cues and greater neutral, relaxed-state cortisol to corticotropin ratio (adrenal sensitivity) were each predictive of shorter time to alcohol relapse.

CONCLUSIONS

These results identify a significant effect of high adrenal sensitivity, anxiety, and increased stress- and cue-induced alcohol craving on subsequent alcohol relapse and treatment outcomes. Findings suggest that new treatments that decrease adrenal sensitivity, stress- and cue-induced alcohol craving, and anxiety could be beneficial in improving alcohol relapse outcomes.

Adrenocortical and pituitary glucocorticoid feedback in abstinent alcohol-dependent women

BACKGROUND

The long-term ingestion of alcohol diminishes hypothalamic-pituitary-adrenal (HPA) axis reactivity in alcohol-dependent men, potentially altering future relapse risk. Although sex differences in HPA axis functioning are apparent in healthy controls, disruptions in this system have received little attention in alcohol-dependent women. In this study, we assessed the basal secretory profile of adrenocorticotropic hormone (ACTH) and cortisol, adrenocortical sensitivity in both the presence and absence of endogenous corticotropic pituitary activation, and feedback pituitary glucocorticoid sensitivity to dexamethasone.

METHODS

Seven women 4- to 8-week abstinent alcohol-only dependent subjects and 10 age-matched female healthy controls were studied. All subjects were between 30 and 50 years old, not taking oral contraceptives, and were studied during the early follicular phase of their menstrual cycle. Circulating concentrations of ACTH and cortisol were measured in blood samples collected at frequent intervals from 2000 to 0800 hour. A submaximal dose of cosyntropin (0.01 microg/kg), a synthetic ACTH (1-24), was administered at 0800 hour to assess adrenocortical sensitivity. In a separate session, low-dose cosyntropin was also administered following high-dose dexamethasone (8 mg intravenous) to assess adrenocortical sensitivity in the relative absence of endogenous ACTH. In addition, the ACTH response to dexamethasone was measured to determine the pituitary glucocorticoid negative feedback. Sessions were 5 days apart, and blood draws were obtained every 5 to 10 minutes.

RESULTS

Mean concentrations and pulsatile characteristics of ACTH and cortisol over 12 hours were not statistically different between the 2 groups. Healthy controls had a somewhat higher (p < 0.08) net peak, but not net integrated, cortisol response to cosyntropin relative to the alcohol-dependent women. There were no significant group differences in either the ACTH or cortisol response to dexamethasone nor in the net cortisol response to cosyntropin following dexamethasone.

CONCLUSION

Significant differences in pituitary-adrenal function were not apparent between alcohol-dependent women and matched controls. Despite the small n, it appears that alcohol-dependent women do not show the same disruptions in HPA activity as alcohol-dependent men. These findings may have relevance for gender-specific treatment effectiveness.

Alcohol and the liver

PURPOSE OF REVIEW

To update the reader with advances in epidemiology, genetics, detection, pathogenesis and therapy of alcohol-related liver disease.

RECENT FINDINGS

Ill-health due to alcohol abuse is improving in some nations but deteriorating in others. Oxidative and nitrosative stress are key to the pathogenesis of alcoholic liver disease, and there is now greater emphasis than previously on their development and role of cytochrome P450 2E1, on mitochondrial stress and disruption, (including elucidation of mitochondrial protection mechanisms) disturbance of signaling pathways and involvement of extrahepatic mediators like adiponectin. Treatment of alcoholic liver disease has stagnated, but transplantation is still favored and debated for end-stage cirrhosis.

SUMMARY

Basic and clinical research into the mechanisms of alcoholic liver disease is making headway, but has yet to produce safe and effective therapies for alcoholic hepatitis and for reversing cirrhosis.

Family history of alcoholism does not influence adrenocortical hyporesponsiveness in abstinent alcohol-dependent men

BACKGROUND

Early abstinence in alcohol-dependent subjects is marked by adrenocortical hyporesponsivity. However, it is uncertain whether the blunted response is primarily attributable to a genetic vulnerability or to the chronic abuse of alcohol. In the present study, the authors investigated the influence of a family history (FH) of alcoholism upon suppressed glucocorticoid reactivity.

METHODS

Twenty-two abstinent alcohol-dependent and 14 control men were studied. The cortisol response was assessed in 11 patients following oCRH infusion (.4 ug/kg) and in a separate group of 11 patients following cosyntropin infusion (.01 ug/kg) preceded by high-dose intravenous dexamethasone (8 mg). FH, as determined by self-report, was assessed using two different methods: history of parental alcoholism and number of alcohol-dependent first- and second-degree relatives.

RESULTS

Neither a parental history or familial loading of alcoholism had a significant effect upon glucocorticoid responsivity in abstinent alcohol-dependent men.

CONCLUSIONS

Adrenocorticol responsiveness in recently abstinent alcohol-dependent men does not appear to reflect a preexisting biologic vulnerability to alcoholism.