Chronic and high alcohol consumption has a negative impact on sleep and sleep-associated consolidation of declarative memory.

BACKGROUND: The importance of sleep for memory consolidation has become a major focus of research. While it is known that abstaining alcohol-dependent patients often have sleep disorders and that there is some cognitive impairment during early abstention a possible interaction of disturbed sleep with overnight memory consolidation has not been addressed in a study as yet. METHODS: Twenty-four alcohol-dependent patients with a short abstention period (mean 21.9 +/- 7.6 days) were compared with 12 patients with an abstention period of several months (115.7 +/- 43.8 days). Groups did not differ with respect to daily alcohol consumption before treatment, duration of alcohol dependence, and age. Before sleep all patients learned a list of semantically associated word pairs and a face name association task to a fixed criterion (at least 60% of correct recall) and they performed a mirror tracing task. After a polysomnographically registered night the patients were tested for retention of the learned declarative material by cued recall and had to perform the mirror tracing task again. RESULTS: The groups did not differ with respect to sleep parameters or sleep-associated memory consolidation. Across both groups the duration of alcohol dependence correlated negatively with the amount of non-REM sleep and recall in the face name association task correlated negatively with daily alcohol consumption before abstention. Among the longer-term abstainers the duration of abstention correlated with the amount of slow wave sleep. CONCLUSIONS: Our data support the hypothesis that chronic and high alcohol consumption negatively affects sleep and declarative memory consolidation during the first months of abstention. Between an abstention period of a few weeks and of several months no change in sleep parameters and nightly memory consolidation could be demonstrated, however.

Gender differences for ghrelin levels in alcohol-dependent patients and differences between alcoholics and healthy controls.

BACKGROUND: Ghrelin is a 28-amino acid gut-brain peptide, mainly secreted by the gastric mucosa. Its effects are linked to energy homeostasis and particularly seem to increase hunger and food intake. In recent years, studies suggested that appetite-regulating peptides, such as ghrelin play a relevant role in alcoholism. Since data published to date on the potential role of ghrelin as state and/or trait marker in alcoholism and the association with craving are controversial, we aimed at further elucidating these aspects. PATIENTS AND METHODS: One-hundred nine alcohol-dependent abstinent patients after withdrawal (27 f, 82 m), (ICD 10 F 10.25) and 45 healthy volunteers (12 f, 33 m) were included. Laboratory testing (Ghrelin RIA 90, Mediagnost Inc., Germany) was performed and several craving scales [Obsessive Compulsive Drinking Scale, Alcohol Urge Questionnaire and Visual Analogue Scale (VAS)] were applied at the beginning and at the end of the 3-week rehabilitation program. RESULTS: (1) Ghrelin levels are significantly higher in female alcohol-dependent patients as compared to controls, not, however, in men alcoholics. (2) In several statistical subanalyses, an association of craving and ghrelin was found. The results, however, remain heterogeneous. CONCLUSION: The data suggest gender-dependent ghrelin levels in alcohol-dependent patients. We therefore conclude, that it might be useful to perform statistical analyses gender-specific. With regard to a potential correlation of ghrelin and craving the results seem to depend on gender, duration of the abstinence period and the instrument used.

Cortisol awakening response in abstinent alcohol-dependent patients as a marker of HPA-axis dysfunction.

Hypothalamo-pituitary-adrenocorticoid (HPA)-axis reactivity to psychosocial or pharmacological stimulants is diminished in alcohol-dependent patients during early abstinence but recovers after several months of abstention. In order to assess the physiological reactivity in the morning we used the cortisol awakening response (CAR) in saliva to compare 24 early abstainers (mean 21.9+/-7.6, range 10-36 days) with 12 alcohol-dependent patients with longer abstention periods (mean 116.8+/-45.7, range 59-230 days) and looked for an association with sleep, especially rapid eye movement (REM) sleep of the preceding night. Both groups did not differ with respect to age, duration of alcohol dependence, daily drinking dosage before detoxification, body mass index, depressivity, level of anxiety, daily cigarette consumption or sleep quality during the preceding 14 days. Sleep in the night before cortisol assessment did not differ with respect to total sleep time (412.4+/-35.9 vs. 407.0+/-38.7 min). Immediately upon awakening and 15, 30, 45 and 60 min later, specimens of salivary cortisol were collected. While starting from equal levels upon awakening longer abstaining patients with alcohol dependence showed a stronger CAR (ANOVA with repeated measurement, time x group effect: F=4.33, p<0.01) with distinctly higher cortisol levels 45 and 60 min after awakening (T=3.79, p<0.001 and T=3.06, p<0.005, respectively). Across both groups the time spent in REM-sleep only correlated with cortisol levels upon awakening (r=0.33, p<0.05). Our data indicate that CAR is a useful tool for investigating alterations in the HPA-axis regulation in abstaining alcohol-dependent patients.