Comparative Validation of the Growth Hormone Releasing Hormone and Arginine Test for the Diagnosis of Adult Growth Hormone Deficiency

Inclusion Criteria: * Subjects aged over 18 years and under 60 years, * Female or male, * Subjects not treated by GH or having stopped the treatment more than 15 days ago, * Effective contraception in women of childbearing age: hormonal contraception or use of female condom and spermicides or use of diaphragm and spermicides or Intra Uterine Device (IUD), * Signed informed consent, * Subjects possessing social security cover. * Subjects having at least one of the following criteria were considered as subjects with a high probability of presenting a GH deficit: * Subjects with a tumour of the hypothalamo-hypophyseal region (hypophyseal adenomata, craniopharyngioma, meningioma, etc.) in whom the presence of a hypophyseal insufficiency in GH must be tested preoperatively or postoperatively, or * Subjects presenting a secondary ante-hypophyseal insufficiency to an inflammatory, infectious, post-traumatic pathology or to a hypophyseal necrosis, whose hypophyseal functional condition has already been documented and for whom a revaluation of GH secretion is desired, or * Subjects having undergone, as adults, an irradiation hypothalamo-hypophyseal region, or a suprasellar irradiation, in a clinical context of GH deficit, or * Subjects with a known organic ante-hypophyseal insufficiency beginning in childhood and with at least 1 associated deficit excluding prolactin. * Subjects having at least one of the following criteria were considered as subjects with a low probability of presenting a GH deficit: * Subjects with known idiopathic isolated GH deficit starting in childhood and for whom a new growth hormone secretion test is desired, or * Subjects with non-operated microadenoma (\< 1 cm of diameter), or * Subjects with fortuitously discovered intrasellar image (e.g. Rathke's pocket cyst). The third category of subjects eligible was made of healthy volunteers. Exclusion Criteria: * Subjects presenting a coronary history or whose electrocardiographic signs evoke an ischemic pathology, * Subjects presenting a history of cerebrovascular insufficiency, * Subjects presenting a history of epilepsy, * Subjects with an evolutive acromegalia or an evolutive Cushing's syndrome, * Subjects presenting a known intolerance to arginine, GHRH or insulin, * Hyperkalemic subjects, * Diabetic subjects (Type 1 or Type 2), * Very obese subjects (BMI \> 40), * Subjects presenting a severe, hepatic, renal, tumoral evolutive affection or metabolic or respiratory acidosis, * Subjects with known immuno-depression, * Subjects with psychiatric disorders, * Subjects presenting Parkinson's disease or Parkinsonian syndromes treated by Levodopa®, * Subjects treated by drugs directly affecting the hypophyseal secretion of somatotrophin (e.g. clonidine, levodopa) or provoking the release of somatostatin, antimuscarinic agents (atropine), * Subjects with untreated hypothyroidism or subjects treated by anti-thyroid synthesis drugs, * Participation in another biomedical research programme less than 3 months previously, * Known evolutive pregnancy or breastfeeding.