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.