[Acromegaly].
Acromegaly is a rare disease usually caused by growth hormone (GH) hypersecretion, due to a pituitary adenoma; in very rare cases, acromegaly is due to ectopic secretion of GHRH, responsible for pituitary hyperplasia. Owing to its insidious onset, acromegaly is often diagnosed late (4 to > 10 years after onset), at an average age of about 40 years, in front of an acquired, slowly progressing disfigurement mainly involving the face and extremities. Acromegaly has also rheumatologic, cardiovascular, respiratory and metabolic consequences which determine its prognosis. The diagnosis is based on an increased serum GH concentration unsuppressed following an oral glucose load (oral glucose tolerance test -OGTT-) and an increased insulin-like growth factor-I (IGF-I); according to a 2000 Consensus statement, if the basal serum GH is above 0,4microg/L (1.2mIU/L) and/or if the IGF-I is elevated, an OGTT must be performed. If the lowest GH value (nadir) during OGTT remains above 1microg/L (3mIU/L), acromegaly is confirmed. With the generalized use of very sensitive assays nowadays, it has recently been considered that this cutoff should be decreased to 0,3microg/L (0.9mIU/L). Treatment is aimed at correcting (or preventing) tumor compression by excising the culprit lesion, and at reducing GH and IGF-I levels to normal values (or at least to a "safe" GH level of < 2microg/L or < 6mIU/L). A stepwise therapeutic strategy is used: transsphenoidal surgery is often the first-line treatment; when surgery fails to correct GH/IGF-I hypersecretion, medical treatment with somatostatin analogs and/or radiotherapy can be used, somatostatin analogs being generally preferred; the GH antagonist (pegvisomant) is used in patients that are resistant or intolerant to somatostatin analogs. Prognosis of acromegaly has improved in the recent years: adequate hormonal disease control is achieved in most cases, allowing life expectancy similar to that of the general population.
Chanson
Philippe
P
Service d'endocrinologie et des maladies de la reproduction, Assistance publique des hôpitaux de Paris, Hôpital de Bicêtre, Faculté de médecine Paris-Sud, Université Paris XI, F-94275 Le Kremlin-Bicêtre, France. philippe.chanson@bct.ap-hop-paris.fr
D000172:Acromegaly / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D000236:Adenoma / Q000150:complications / Q000601:surgery; D000367:Age Factors; D005951:Glucose Tolerance Test; D019382:Human Growth Hormone / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D010911:Pituitary Neoplasms / Q000150:complications / Q000601:surgery; D011379:Prognosis; D012307:Risk Factors
D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I