ASSESSMENT OF FUNCTIONAL LIVER MASS AND PLASMA-FLOW IN ACROMEGALY BEFORE AND AFTER LONG-TERM TREATMENT WITH OCTREOTIDE

Functional liver mass and functional liver plasma flow (FLPF) were ass essed in 11 patients with clinical features of acromegaly by determini ng galactose elimination capacity (GEC) and extrarenal clearance of so rbitol, before and 5 to 7 months after treatment with the long-acting somatostatin analog, octreotide (150 to 600 mu g/d in three subcutaneo us injections). Growth hormone (GH) and insulin-like growth factor-I ( IGF-I) levels, as well as liver size by ultrasound, were also recorded . Baseline GEC was increased in every patient but one, for a mean of 0 .78 +/- 0.10 g/min (normal, 0.53 +/- 0.07; P <.01). At reevaluation af ter 5 to 7 months of octreotide treatment, a significant reduction of GEC was observed (0.62 +/- 0.08 g/min, P <.001). Changes of GEC parall eled those of GH (38.6 +/- 34.4 v 11.7 a 15.2 mu g/L P <.01) and IGF-I (5.0 +/- 1.7 v 2.7 +/- 2.2 U/ml, P <.001). Significant correlations w ere found between GEC and GH (r =.50, P <.05) and between GEC and IGF- I (r =.55, P <.01). FLPF, assessed by extrarenal clearance of sorbitol , was within the normal limit in all cases (0.98 +/- 0.19 v 0.97 +/- 0 .12 L/min, NS) and remained normal after 5 to 7 months of octreotide t reatment (0.99 +/- 0.11 L/min). Hepatic structure determined with ultr asonic scanning and conventional liver-function tests were basally nor mal in all patients, with a slight increase of liver volume in three c ases. No change of biochemical and/or morphological features occurred during follow-up evaluation. The results support the hypothesis that G H and especially IGF-I enhance liver metabolic capacity; conversely, f unctional liver perfusion is largely independent of their actions. Our data also suggest that octreotide is unable to produce well-structure d changes of liver circulation when administered long-term. Copyright (C) 1996 by W.B. Saunders Company