Serum 7α–hydroxycholesterol reflects hepatic bile acid synthesis in patients with obstructive jaundice after external biliary drainage

Abstract

To examine the hypothesis that serum levels of 7 alpha-hydroxycholesterol reflect bile acid synthesis in the liver, we analyzed serum 7 alpha-hydroxycholesterol and bile acid output in 13 patients with obstructive jaundice after relief of biliary obstruction. Before biliary drainage, the serum level of 7 alpha-hydroxycholesterol was 92 +/- 12 pmol/ml (mean +/- S.E.M.) and was significantly lower than the control value (226 +/- 26 pmol/ml, p < 0.01). After biliary drainage, serum 7 alpha-hydroxycholesterol level and biliary bile acid outputs began to rise in some patients, indicating reversible liver dysfunction. In other patients, serum 7 alpha-hydroxycholesterol levels and bile acid outputs did not increase, suggesting severe or irreversible liver dysfunction. On and after the third day of biliary decompression, serum 7 alpha-hydroxycholesterol levels correlated well with bile acid excretion (p < 0.01, r = 0.93). Other liver function parameters, such as serum bilirubin, serum bile acids, albumin, and bile flow, also revealed significant correlation with serum 7 alpha-hydroxycholesterol levels. We conclude that the serum 7 alpha-hydroxycholesterol level clearly reflects bile acid synthesis in the liver and that it may serve as a useful parameter for the assessment of hepatic functional recovery in patients with obstructive jaundice after biliary drainage.