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 system in patients with Alzheimer's disease (AD) and in patients with vascular dementia (VD) in relation with somatostatin cerebrospinal levels. DESIGN We studied the GH response to GHRH in controls and in AD and VD patients and correlated their responses with somatostatin cerebrospinal levels.


METHODS
Twelve control subjects and 56 patients, 28 with AD and 28 with VD, were studied. A GHRH test was performed in every case. One hundred mcg of GHRH was administered as a intravenous bolus and blood samples were drawn at -15, 0, 30, 60, 90 and 120 minutes. Cerebrospinal fluid was obtained after lumbar puncture. Measurements of GH and somatostatin were determined by specific radioimmunoassay.


RESULTS
The GH response to GHRH exhibited no difference between AD and VD patients (12.2 +/- 2 mcg/l vs 9.9 +/- 1.8). There were 17 AD patients and 16 VD patients with exaggerated GH response to GHRH. There was no 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 correlation among GH response to GHRH and cerebrospinal levels.


CONCLUSIONS
In our study we observed no difference between the AD and VD patients in GH response to GHRH and no difference in somatostatin cerebrospinal levels in these patients.
Gómez
I M
IM
Endocrinology, Neurology and Biochemistry Services, Hospital de Bellvitge, Barcelona, Spain.
Aguilar
M
M
Navarro
M A
MA
Ortolà
J
J
Soler
J
J
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000134:cerebrospinal fluid; D015140:Dementia, Vascular / Q000097:blood* / Q000134:cerebrospinal fluid; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013004:Somatostatin / Q000134:cerebrospinal fluid*
D019382:Human Growth Hormone; D013004:Somatostatin; D013007:Growth Hormone-Releasing Hormone