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Age-related changes of the hypothalamic-pituitary-adrenal axis: pathophysiological correlates.
- Ferrari E, Cravello L, Muzzoni B, Casarotti D, Paltro M, Solerte SB, Fioravanti M, Cuzzoni G, Pontiggia B, Magri F
Eur J Endocrinol. 2001 Apr;144(4):319-29.
The aim of this review was to examine the evidence for age-related changes of the hypothalamic-pituitary-adrenal (HPA) axis in both physiological and pathological
aging,
on the basis of the many data in the literature,
as well as of our personal findings. A statistically significant circadian rhythmicity of serum
cortisol
was maintained in elderly subjects, even if with a reduced amplitude
of the 24 h fluctuations and a trend to an increase of the serum
levels in the evening and at night-time, in comparison with young controls. Furthermore, an age-related impairment of HPA sensitivity
to steroid
feedback
was present in elderly people. The occurrence of senile dementia
amplified the changes already present in physiological aging.
While the cortisol
secretion was generally well maintained in aging,
the adrenal
production of dehydroepiandrosterone and of its sulfate (DHEAS) exhibited an age-related decline. Therefore, the cortisol/DHEAS molar ratio was significantly higher in elderly subjects and even more in demented ones, than in young controls. Due to the opposite effects of cortisol
and DHEAS on the brain and particularly on the hippocampal
region, the imbalance between glucocorticoids
and androgens
occurring in physiological and even more in pathological
aging,
may have adverse
effects on the function of this region, whose key role
in learning and memory is well known.
This abstract at PubMed.