CHOLESTEROL-METABOLISM AND SERUM AND BILIARY NONCHOLESTEROL STEROLS IN GALLSTONE PATIENTS DURING SIMVASTATIN AND URSODEOXYCHOLIC ACID TREATMENTS

Effects of long-term high-dose ursodeoxycholic acid (UDCA) and simvast atin treatments on cholesterol metabolism and biliary lipid compositio ns were compared in patients with cholesterol gallstones, Absorption a nd synthesis of cholesterol, serum and biliary noncholesterol sterols and lipids were determined in 14 patients randomized to UDCA (23-25 mg /kg/d) or simvastatin (40 mg/d) for 1 year. Simvastatin reduced serum low-density lipoprotein cholesterol by 55%, and UDCA, by 9%. Cholester ol absorption was decreased (35%) by UDCA, but nonsignificantly increa sed by simvastatin (P < .05 for difference of changes caused by the tw o drugs), Whole-body synthesis and biliary output of cholesterol were both significantly decreased only by UDCA, In addition, UDCA inconsist ently increased the proportions of serum and biliary precursor sterols of cholesterol, known to reflect cholesterol synthesis, but did not a ffect their biliary secretions, Simvastatin, however, dramatically red uced serum and also biliary cholesterol precursor sterol proportions a nd their biliary secretions and increased proportions of serum and bil iary plant sterols and cholestanol, known to reflect cholesterol absor ption, but had no effect on their biliary secretion. Only UDCA signifi cantly decreased the molar percentage of cholesterol, the lithogenic i ndex, and the cholesterol/phospholipid (CH/PL) ratio in bile, whereas both treatments inconsistently decreased the vesicular CH/PL ratio (P < .07 in both groups), It is concluded that both drugs decreased serum cholesterol and inhibited cholesterol synthesis, but had a differing influence on precursor sterols and the absorption of cholesterol. UDCA had more beneficial effects than simvastatin on the antilithogenic pr operties of bile.