Dissociation of Changes in Plasma Cholesterol and Hepatic Cholesterol Synthesis, Assessed by Precursors in Bile, after Jejunoileal Bypass with 3:1 and 1:3 Jejunoileal Ratio

Abstract

Hepatic cholesterol synthesis, assessed by the biliary content of post-squalene cholesterol precursors relative to cholesterol, was related to fasting plasma cholesterol fractions in obese patients before (n = 7) and after jejunoileal bypass surgery with either a 3:1 ratio (n = 15) or a 1:3 ratio (n = 14) between jejunum and ileum left in function. The content of precursors increased after bypass surgery, and more so with a 3:1 than with a 1:3 jejunoileal ratio. However, the two types of bypass resulted in similar reductions in plasma concentrations of total cholesterol and low-density lipoprotein cholesterol. Within the unoperated group and the 3:1 bypass group the precursor content and plasma cholesterol levels were, as expected, inversely correlated, but within the 1:3 bypass group there were either weaker or even positive correlations. These findings suggest that the link between stimulation of hepatic cholesterol synthesis and reduction in plasma cholesterol may depend on the length of jejunum and ileum left in function.

Key Words:

• Cholesterol synthesis
• jejunoileal bypass
• plasma cholesterol
• plasma lipoproteins