[The place of insulin-like growth factor I in the diagnosis of acromegaly].

Insulin-like growth factor-I (IGF-I) and basal growth hormone (GH) (average of GH values measured at -20 an 0 minutes) levels were measured in 32 (29 treated, 3 untreated) patients with acromegaly. In 15 patients IGF-I and basal GH values were normal. In 12 patients both GH and IGF-I were elevated. In 5 cases normal basal GH and elevated IGF-I levels were found. We assume that elevated serum level of IGF-I is a reliable sign of acromegalic activity. Compared to this, the basal GH level proved to be a much less reliable indicator to predict or exclude active acromegaly (sensitivity: 0.7, specificity: 1, positive predictive value: 1, negative predictive value: 0.75).