Submitted on July 27, 2006
Revised on September 5, 2006
Accepted on September 7, 2006
The lipid-lowering effect of ezetimibe in pure vegetarians
Jacob J. Clarenbach, Michael Reber, Dieter Lutjohann, Klaus von Bergmann, and Thomas Sudhop
Scientific Service, Federal Institute for Drugs and Medical Devices, Bonn 53175
Corresponding Author: sudhop{at}bfarm.de
Background Results of previous studies have shown that ezetimibe (10 mg/day) reduces LDL cholesterol in patients with mild hypercholesterolemia on a normal cholesterol diet (dietary intake 200-500 mg/d) by 16 to 22 %. However, the LDL cholesterol-lowering effect of ezetimibe in subjects with an extremely low dietary cholesterol intake (vegetarians) has not been studied so far. Methods We conducted a randomized, double-blind, placebo-controlled, two-phase cross-over study in 18 healthy pure vegetarians to assess the effect of ezetimibe (10 mg/day) on plasma lipids, cholesterol absorption, and its synthesis. Treatment periods lasted 2 weeks each, with an intervening 2-week wash-out period. Fractional cholesterol absorption was determined using the continuous dual stable-isotope feeding method. Results Mean dietary cholesterol intake in the pure vegetarians was extremely low and averaged 29.4 ± 16.8 mg/day and 31.4 ± 14.4 mg/day during the placebo and ezetimibe administration phases, respectively. Fractional cholesterol absorption during placebo was 48.2 ± 8.2% and was lowered by -58% during ezetimibe treatment to 20.2 ± 6.2% (p<0.001). This change in intestinal cholesterol absorption was followed by a significant reduction in LDL cholesterol by 17.3%. Conclusion In individuals with extremely low dietary cholesterol intake, treatment with ezetimibe (10 mg/d) leads to a significant reduction of cholesterol absorption and clinically relevant decrease of plasma LDL cholesterol, comparable to subjects with a normal dietary cholesterol intake. Thus, the lipid-lowering effect of ezetimibe is mediated mainly through a reduction of the absorption of endogenous (biliary) cholesterol.