The aim of the study is to determine the specificity and sensitivity of the combined growth hormone releasing hormone (GHRH) + Arginine test in healthy volunteers, subjects with highly probable adult growth hormone deficiency (AGHD) and subjects who were probably free of AGHD.

The randomisation was carried out before the first test was performed. In order to be informed of the subject's randomisation group, the investigator phoned the access number given to him/her. The subject's allocation to a given randomisation arm was determined on the basis of a centralised randomisation (answering service), balanced per group of subjects with a minimisation on 2 criteria: age and BMI. This was a centralised randomisation using a Interactive Voice Response System (IVRS) which was balanced in each of the following 3 categories of subjects: * Category A = healthy volunteers, * Category B = subjects with a strong probability of deficit in GH, * Category C = subjects with a low probability of deficit in GH. In each of these 3 categories, the subjects underwent 3 tests whose sequences were determined by the following randomisation group: * Group 1: GHRH+Arg, GHRH+Arg, ITT or * Group 2: ITT, ITT, GHRH+Arg.