Abstract
The influence of the gallbladder and the sphincter of Oddi on the diurnal rhythm of bile lipid composition was assessed by determining the lithogenic index at 4-h intervals over a period of 24 h in 29 cholecystectomized and papillotomized patients with a nasobiliary tube receiving a normal hospital diet and in 9 during 1-day fast. With a normal diet, biliary cholesterol concentrations dropped during the daytime (p < 0.05), and total biliary lipid, bile acid, phospholipid, and cholesterol concentrations rose at night (p < 0.05). During fasting, total biliary lipid, phospholipid, and cholesterol concentrations rose continuously (p < 0.01). Even with loss of function of the gallbladder and sphincter of Oddi, a diurnal rhythm of biliary lithogenicity persisted, caused mainly by cholesterol increases during fasting. Concomitant increases in phospholipids and, to a lesser extent, bile acids modulated these changes.