Gallbladder

Bile acid synthesis declines, reflecting a significant reduction in the hydroxylation of cholesterol (cholesterol 7 -hydroxylase). This change may contribute to the increased incidence of cholelithiasis (gallstones) in the elderly. A similar age-related decrease in hepatic extraction of low-density lipoprotein cholesterol from the blood occurs, elevating serum cholesterol levels and possibly promoting coronary artery disease in the elderly. Both stimulated and fasting concentrations of cholecystokinin (a peptide hormone released from duodenal mucosa that contracts the gallbladder and relaxes the biliary sphincter) are higher in elderly people. However, gallbladder emptying rates and fasting and nonfasting gallbladder volumes do not change with aging, suggesting diminished sensitivity to the effects of cholecystokinin.

This topic was last updated May 2005.