Elevated urinary free cortisol in patients with dementia.

Urinary free cortisol (UFC), 17-hydroxycorticosteroids (17-OHCS) in urine and dexamethasone suppression test (DST) were examined in patients with dementia of Alzheimer type (DAT) and multi-infarct dementia (MID), and nondemented elderly. Eight of 19 patients (42.1%) were DST nonsuppressor. UFC was significantly elevated in patients with dementia, compared with that in nondemented elderly. There was no difference in UFC levels between DAT and MID. The UFC level correlated with post-DST plasma cortisol level at 1600 in demented patients. The mean level of 17-OHCS in demented patients was increased, although the difference was not significant statistically. In demented patients, UFC levels, not 17-OHCS levels in urine were correlated with Mini-Mental State Examination scores. These results suggest that a hypothalamo-pituitary-adrenal axis function is activated in demented patients and that this activation relates generally to dementation itself, not to an etiology of dementia. Measurement of UFC might be a biological marker of dementia and may have a value in diagnosis of dementia.