Increased plasma cortisol levels (correlated with increased hypothalamic-pituitary-adrenal axis activity) may be associated with more rapid disease progression in Alzheimer-type dementia (AD). In a study conducted at the Washington University School of Medicine in St Louis, Dr John Csernansky and colleagues assessed 33 patients with very mild or mild AD and 21 persons without AD annually for up to 4 years, using the Clinical Dementia Rating Scale and various neuropsychological tests. Plasma was obtained from each patient and assessed for cortisol level.
Patients with AD who had higher initial plasma cortisol levels had more rapidly increasing symptoms of dementia (P = .007) and more rapidly decreasing performance on tests associated with temporal lobe function (P = .014). In the patients without AD, no significant associations were found between initial plasma cortisol levels and psychological testing scores. There was no significant difference between the groups in mean scores on the Geriatric Depression Scale.
"It is especially intriguing that plasma cortisol levels were associated with the rate of change in the neuropsychological factor measure weighted toward memory function and previously found to be associated with neuropathological burden in the temporal lobe from Alzheimer's disease," the investigators commented. "Our findings raise the possibility that increased glucocorticoid levels have a disproportionate impact on the Alzheimer's disease process as it develops in the hippocampus and other structures of the medial temporal lobe." The authors emphasized the need to further confirm and extend these results by examining other measures of disease progression in a greater number of participants with AD.