GROWTH-HORMONE SECRETION IN PRIMARY DEGENERATIVE DEMENTIA - CORRELATIONS WITH COGNITIVE IMPAIRMENT

Changes in brain peptides and neurotransmitters are thought to elicit alterations of growth hormone (GH) secretion in dementia. Baseline GH levels and hormone responses to GH-releasing hormone (GHRH)--administe red alone or after pyridostigmine pretreatment-were evaluated in 17 pa tients, aged 52-83, with primary degenerative dementia quantified by t he Clinical Dementia Rating (CDR) Scale and the Mini-Mental State Exam ination (MMSE) with a view to detecting correlations between neuroendo crine and clinical data. Basal GH levels were not statistically differ ent in patients and in age-matched controls. However, when patients we re split into the three CDR groups of disease severity, basal GH level s were significantly higher in those with more severe dementia than in all other patients and in controls. GH responses to GHRH, evaluated b oth in terms of peaks attained after simulation and of secretion areas under the curve (AUC), were significantly higher in patients than in controls after pyridostigmine pretreatment, but not after the infusion of GHRH alone. Patients with mild to moderate dementia had GH peaks a fter GHRH higher than more severe patients. Pyridostigmine did not pot entiate GHRH effects in the more severe cases. The scores on Rey's 15- word test for memory function were directly correlated with GH peaks a fter GHRH. No correlations were found between GH data, age, body weigh t, disease duration and scores at other psychometric assessments such as MMSE, Raven's matrices, verbal fluency or WAIS tests.