Search Results

You are looking at 1 - 2 of 2 items for

  • Author: Christoph Dodt x
Clear All Modify Search
Restricted access

Christoph Dodt, Karl-Josef Theine, Dirk Uthgenannt, Jan Born and Horst Lorenz Fehm

Dodt C, Theine K-J, Uthgenannt D, Born J, Fehm HL. Basal secretory activity of the hypothalamo–pituitary–adrenocortical axis is enhanced in healthy elderly. An assessment during undisturbed nighttime sleep. Eur J Endocrinol 1994;131:443–50. ISSN 0804–4643

The process of aging is characterized by a disturbed neuroendocrine regulation, including a changed secretory activity of the hypothalamo–pituitary–adrenocortical (HPA) axis. In the present study adrenocorticotropin (ACTH) and cortisol secretion was monitored during nocturnal sleep (controlled by somnopolygraphy) in healthy aged men (N = 10, age range 70–92 years, mean 78.2 years) and women (N = 10, age range 70–88 years, mean 78.6 years), and in young male controls (N = 16, age range 20–34 years, mean 24.9 years). Blood was drawn every 15 min. Most important, basal HPA secretory activity was enhanced distinctly in the elderly, as indicated by significantly elevated nadirs of plasma cortisol and ACTH concentrations occurring during early nocturnal sleep (p < 0.001, compared to young controls) and by elevated average levels of cortisol and ACTH between 23.00 and 03.00 h (p < 0.001). The first rise in nocturnal plasma cortisol began, on average, 67 min earlier than in young controls (p < 0.005). Changes of endocrine activity were associated with marked reductions of slow-wave sleep (SWS, p < 0.05) and rapid eye movement (REM) sleep in the elderly (p < 0.01), while time awake and in stage 1 sleep was increased. The REM sleep coincided with decreased HPA secretory activity, irrespective of age, indicating that the link between the ultradian sleep structure and the secretory HPA activity is maintained in the elderly. It is concluded that the agerelated elevation of basal HPA secretory activity is of central nervous origin, leading to a phase advance of the circadian pacemaker and an elevation of the basal secretory rate of the HPA axis. Considering complementary results from animal studies, it is suggested that basal HPA hypersecretion associated with SWS deficits in the elderly are markers for an altered function of hippocampal corticosteroid receptors which are involved in the tonic inhibition of HPA secretory activity.

C Dodt, Klinische Forschergruppe "Klinische Neuroendokrinologie", Zentrum Innere Medizin, Medizinische Universität zu Lübeck. Ratzeburger Allee 160, D-23538 Lübeck, Germany

Restricted access

Jan Born, Ina Ditschuneit, Martin Schreiber, Christoph Dodt and Horst L Fehm

Born J, Ditschuneit I, Schreiber M, Dodt C, Fehm HL. Effects of age and gender on pituitary-adrenocortical responsiveness in humans. Eur J Endocrinol 1995;132:705–11. ISSN 0804–4643

This study compared plasma concentrations of adrenocorticotropin (ACTH) and cortisol in young men (N = 10, mean age 24.4 years), young women (N = 10, mean age 25.4 years), old men (N = 8, mean age 81.6 years) and old women (N = 8. mean age 83.5 years) under basal resting conditions and after stimulation with either human corticotropin-releasing hormone (hCRH, 100 μg iv) or a combined injection of hCRH (100 μg and arginine vasopressin (VP, 0.5 IU iv). Basal secretion of cortisol did not differ among groups, but basal concentrations of ACTH were diminished in young women (p < 0.01), indicating an enhanced adrenal sensitivity to ACTH in these subjects. Pituitary responses to hCRH did not differ between young men and women. However, responses to hCRH/VP were stronger in the young females (p < 0.01), suggesting an enhanced pituitary responsiveness to the augmenting effect of VP on ACTH release in this group. Pituitary-adrenal secretory responses were greater in old than in young men after sole injection of hCRH (p < 0.05) and even more so after combined injection of hCRH/VP (p < 0.01). In old women, pituitary-adrenal secretory responses were also greater than in young women (p < 0.05). But, in particular for responses to hCRH/VP, these effects were less distinct than within the men. Results indicate an enhancing effect of age on pituitary responsiveness to the hypothalamic secretagogues hCRH and VP, modulated by the subject's gender.

Jan Born, Klinische Forschergruppe, Klinische Neuroendokrinologie, Medizinische Universität zu Lübeck, Haus 23 a, Ratzeburger Allee 160, 23538 Lübeck, Germany