Association between changes in adrenal secretion and cerebral morphometriccorrelates in normal aging and senile dementia

The circadian organization of adrenal secretion was studied in 23 healthy e lderly subjects, 23 elderly demented patients and 10 healthy young subjects , in order to investigate the relationships between the hypothalamic-pituit ary-adrenal axis and some cerebral morphometric parameters. The cerebral mo rphometric analysis was performed in some subjects of the three groups by M RI. A significant increase in cortisol levels during evening and nighttime was found in both groups of the aged subjects. In elderly subjects, particu larly if demented, the mean serum dehydroepiandrosterone sulfate (DHEAs) le vels throughout the 24-hour cycle were significantly lower than in young co ntrols. A significant reduction of the hippocampal and temporal volume and an enlargement of the lateral ventricles were found in aged subjects, these changes being significantly related to subjects' age, Moreover, the hippoc ampal volume was positively correlated with the circadian mesor of DHEAs (i .e., the circadian rhythm adjusted mean) and with the cortisol nocturnal in crease. Our data may suggest the existence of a link between the selective impairment of cortisol secretion and DHEAs levels, and the progression of h ippocampal degeneration. Copyright (C) 2000 S. Karger AG, Basel.