Growth hormone and thyrotropin hormone secretion in Alzheimer's disease.

The present study examined the relationship among GH and TSH secretion and neuropsychological and morphological tests in patients with Alzheimer's disease (AD). We studied 28 healthy controls and 28 AD patients with psychoneurological tests, and correlated their data with morphological data obtained by computed tomography and hormone responses of GH to GHRH, and TSH to TRH. The GH response to GHRH was higher in AD patients than in controls, 12.2 +/- 2 vs. 5.2 +/- 2.1 mcg/l, p< 0.01 but there was no difference in TSH response to TRH. On neuropsychological tests, patients were classified into 3 stages, these were indistinguishable on the basis of morphological data, GH and TSH responses at all stages including early-onset. Although GH response to GHRH was higher in AD patients than in controls, our results suggest that psychometric discrimination may be more accurate in diagnosis and staging of AD, than in predicting by morphological and hormonal responses.