Biochemical evidence supporting the Cortina criteria

Whether acromegaly is inactive or active, respectively cured or not cured depends on the GH suppressibility and the basal IGF-I level. According to the Cortina criteria, GH suppression after oral ingestion of 75 g glucose to <1 microg/l using conventional polyclonal immunoassays and an IGF-I level within the age-matched normal range are regarded as evidence of good control of acromegaly. According to more recent publications, mortality, which is increased in active acromegaly, is normalized when GH and IGF-I levels have become normal as defined above. Morbidity, i.e. typical features of acromegaly like cardiac problems, carpal tunnel syndrome, carbohydrate intolerance, and excessive sweating may also improve though painful arthropathy, and coarse facial features usually remain unaltered even if the biochemistry has been completely normalized. Using more sensitive GH assays, a group of acromegalic patients was shown to have normal IGF-I levels after surgery, with post-glucose levels of GH <1 microg/l but >0.14 microg/l, which is the upper level of normal subjects and of a second group of successfully operated acromegalic patients. The latter group also had slightly lower IGF-I levels, though such levels were normal in both groups. Whether this may indicate that these patients who have higher GH levels after oral glucose measured with the more sensitive immunoradiometric assay (IRMA) will more likely develop recurrences remains to be demonstrated in a larger cohort. According to the criteria put forward in Cortina d'Ampezzo in February 1999, all patients who have post-glucose GH levels <1 microg/l and normal age-matched IGF-I levels have to be regarded as well controlled, i.e. sufficiently treated. Because of lack of evidence, there is at present no reason to change the consensus reached there.