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

To examine the hypothesis that serum levels of 7α‐hydroxycholesterol reflect bile acid synthesis in the liver, we analyzed serum 7α‐hydroxycholesterol and bile acid output in 13 patients with obstructive jaundice after relief of biliary obstruction. Before biliary drainage, the serum level of 7α‐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 7α‐hydroxycholesterol level and biliary bile acid outputs began to rise in some patients, indicating reversible liver dysfunction. In other patients, serum 7α‐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 7α‐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 7α‐hydroxycholesterol levels. We conclude that the serum 7α‐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. (Hepatology 1994;20:95–100.)