GH RESPONSE TO GH-RELEASING HORMONE (GHRH) IN ALZHEIMER AND VASCULAR DEMENTIA - RELATION WITH SOMATOSTATIN CEREBROSPINAL LEVELS

Objective. To clarify the functional state of the somatotropinergic sy stem in patients with Alzheimer's disease (AD) and in patients with va scular dementia (VD) in relation with somatostatin cerebrospinal level s. DESIGN We studied the GH response to GHRH in controls and in AD and VD patients and correlated their responses with somatostatin cerebros pinal levels. Patients. Twelve control subjects and 56 patients, 28 wi th AD and 28 with VD, were studied. A GURU test was performed in every case. One hundred meg of GHRH was administered as a intravenous bolus and blood samples were drawn at -15, 0, 30, 60, 90 and 120 minutes. C erebrospinal fluid was obtained after lumbar puncture. Measurements of GH and somatostatin were determined by specific radioimmunoassay. Res ults. The GH response to GHRH exhibited no difference between AD and V D patients (12.2 +/- 2 mcg/l vs 9.9 +/- 1.8). There were 17 AD patient s and 16 VD patients with exaggerated GH response to GHRH. There was n o difference between cerebrospinal levels of somatostatin (30 +/- 2.1 pg/mL in AD patients vs 42 +/- 2.4 in VD patients), and there was no c orrelation among GH response to GHRH and cerebrospinal levels. Conclus ion. In our study we observed no difference between the AD and VD pati ents in GH response to GHRH and no difference in somatostatin cerebros pinal levels in these patients.