[Acute test with subcutaneous octreotide as a predictor of the response to treatment with octreotide LAR].

Somatostatin analogues are frequently used to treat acromegaly. To determine the value of the acute test (AT) with subcutaneous (SC) octreotide as a predictor of the response to treatment with octreotide LAR, we analyzed data from 20 patients. For the AT, blood was drawn before and two hours after the SC administration of octreotide for measuring GH. GH levels before and after the AT were 21.9 ng/mL (2.3-143.4) and 3.1 ng/mL (0.3-61.3), respectively. Control of the disease was defined as: GH< 2.5 ng/mL and normal IGF-I anytime during treatment. Sensitivity, specificity, positive and negative predictive values of the AT were 0.9, 0.6, 0.69 and 0.86 for a reduction of 75% of the GH on the test. From our sample we conclude that a 75% reduction of the GH levels during the acute test was able to discriminate patients with a higher or lower chance of responding to treatment.