An assessment of hypothalamo-pituitary-adrenal axis functioning in non-depressed, early abstinent alcoholics

Abstract

Chronic alcohol consumption has been shown to be associated with abnormalities in the regulation of the hypothalamo-pituitary-adrenal (HPA) axis in humans. However, conflicting data exist in the literature, with particular regard to studies performed in actively drinking or withdrawn alcoholics; in addition, the frequent presence of depressive disturbances in such patients may importantly affect the neuroendocrine findings. In this study, we investigated HPA function in 12 male alcoholics, in whom the presence of depression and other possible confounding factors was excluded, during the first and second weeks after cessation of ethanol intake. The plasma corticotropin (adrenocorticotropic hormone, ACTH) and cortisol levels in response to both a stimulation test with human corticotrophin-releasing hormone (CRH; 100 micrograms IV) and an insulin (0.15 UI/kg IV)-induced hypoglycaemia (ITT) were measured; the cortisol response to a standard overnight dexamethasone (1 mg) suppression test (DST) was also tested. While the mean baseline ACTH and cortisol levels, measured in the morning (0800-0830 h), were not different from those of controls, ACTH and cortisol responses to the CRH test were markedly reduced (area of secretion p < .01 and p < .05, compared to controls). Similarly, the patient group showed an almost absent ACTH and cortisol release following insulin infusion (area of secretion p < .01 compared to controls, in either case). In four patients, non-suppression of plasma cortisol levels was seen on the DST, but no significant difference from normal suppressors was noted as far as the clinical features were concerned. These findings suggest that impaired hypothalamic and pituitary responsiveness, unrelated to depressive disturbances, occurs in recently withdrawn chronic alcoholics. While the possible influence of the alcohol withdrawal syndrome should be taken into account, such a pattern may be due to increased activity of the HPA axis, even in the face of preserved basal adrenal secretion. Whether these findings reflect a direct effect of sustained ethanol exposure on the components of the HPA axis, or a non-specific marker of impaired adaptation in chronic alcoholics, deserves further investigation.