Comparison of Provocative Tests for the Diagnosis of Adult Growth Hormone Deficiency in Normal Adults

ABSTRACT

OBJECTIVE: To compare the Madopar(R) (Levodopa Benserazide) test with Insulin Tolerance Test (ITT) as a provocation test for growth hormone (GH). METHOD: One hundred eighty-seven subjects who had not organic disease such as hypothalamic-pituitary disease were studied. Seventy-one subjects underwent an ITT by injection of 0.1 U/kg of regular insulin and blood samples for GH assay were taken at 0, 30, 60 and 120 minutes. One hundred sixteen subjects underwent a Madopar(R) test by administration of Madopar(R) and blood samples for GH assay were taken at 0, 60, 120 and 180 minutes. RESULTS: The GH mean peak response in ITT was significantly higher than that of the Madopar(R) test. Below 50 years, 18 of ITT and 24 of Madopar(R) test showd a GH peak response of less than 5 ng/ml. Above 50 years, 14 of ITT and 53 of Madopar(R) test showd a GH peak response of less than 5 ng/ml. CONCLUSION: The results suggested that the GH response to the Madopar(R) test was much less than that of the ITT. The Madopar(R) test was limited in diagnosis of the adult GH deficiency in normal adults.