EFFECTS OF OCTREOTIDE ON BILIARY LIPID-COMPOSITION AND OCCURRENCE OF CHOLESTEROL CRYSTALS IN PATIENTS WITH ACROMEGALY - A PROSPECTIVE-STUDY

Treatment with the somatostatin analog octreotide is associated with i ncreased gallstone formation. The mechanism of formation of these ston es is unclear. The purpose of this study was to examine the effect of a three-month treatment with octreotide on biliary lipid composition a nd the occurrence of cholesterol crystals in patients with acromegaly. Thirteen patients with active acromegaly, aged 24-76 years, received octreotide (100 mu g three times daily) for three months. Fasting gall bladder bile was obtained during upper gastrointestinal endoscopy afte r ceruletide stimulation. Bile was studied before and at the end of th e treatment period (N = 7), only before (N = 4), or only at the end of treatment (N = 2). Before treatment, all bile samples but one were su persaturated with cholesterol. However, none contained cholesterol cry stals on microscopic examination. At the end of the treatment period, all but two samples were supersaturated with cholesterol. Three of nin e samples contained cholesterol crystals, a proportion significantly h igher than before treatment. The relative proportions of bile acids, c holesterol, and phospholipids, and the mean cholesterol saturation ind ex were not different before and during treatment. Follow-up ultrasono graphy showed the occurrence of gallstones in four patients, including the three patients who had cholesterol crystals. We conclude that: (1 ) fasting gallbladder bile of patients with acromegaly is frequently s upersaturated with cholesterol; (2) treatment with octreotide does not increase cholesterol saturation index, but may induce the occurrence of cholesterol crystals. The data are consistent with the view that ga llstones induced by octreotide are cholesterol stones and suggest that the drug may impair gallbladder motility and/or decrease cholesterol nucleation time.