Conditions: Hypercholesterolemia Coronary Heart Disease
Keywords: Phytosterols Ezetimibe Cholesterol Excretion Cholesterol Absorption Diet Mass Spectrometry Deuterium
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 22
Healthy volunteers: yes

Brief summary:
Phytosterols and ezetimibe each reduce intestinal cholesterol absorption by 30-55% but appear to have different mechanisms of action. The investigators' hypothesis is that phytosterols and ezetimibe given together will block cholesterol absorption in an additive fashion. In a randomized, placebo-controlled crossover trial the effects of placebo, ezetimibe treatment and ezetimibe plus phytosterol treatment will be measured.

Detailed description:
The investigators will perform a randomized, placebo-controlled crossover feeding study in 25 subjects with greater than ideal levels of LDL cholesterol who do not require anti-cholesterol drug treatment. Subjects will consume a baseline diet provided by a feeding center that is deficient in phytosterols for three periods of 21 days separated by 7-day washout periods. Treatments will be given in random order During period B placebo phytosterols and placebo ezetimibe will be given; during period C placebo phytosterols and active ezetimibe will be given; during period A active phytosterols and active ezetimibe will be given. Study endpoints are fecal cholesterol excretion and percent cholesterol absorption determined by gas chromatography/mass spectrometry and circulating LDL cholesterol.

Arms:
arm 1: The order of treatments is A (phytosterols + ezetimibe), B (double placebo), and C (active ezetimibe and phytosterol placebo). arm 2: The order of treatments is B (double placebo), C (active ezetimibe and phytosterol placebo), and A (phytosterols + ezetimibe). arm 3: The order of treatments is B (double placebo), A (phytosterols + ezetimibe), and C (active ezetimibe and phytosterol placebo) arm 4: The order of treatments is A (phytosterols + ezetimibe), C (active ezetimibe and placebo phytosterols, and B (double placebo). arm 5: The order of treatments is C (active ezetimibe and placebo phytosterols), A (phytosterols + ezetimibe), and B (double placebo). arm 6: The order of treatments is C (active ezetimibe and placebo phytosterols), B (double placebo), and A (phytosterols and ezetimibe).

Interventions: intervention 1: Ezetimibe intervention 2: Phytosterols + ezetimibe intervention 3: Placebo
Intervention descriptions: intervention 1: Subjects will undergo three diet periods of 21 days each separated by 7 day washouts. Food will be supplied by a metabolic kitchen and will consist of a phytosterol-deficient baseline diet. During each period subjects will receive either phytosterol esters or placebo and ezetimibe or placebo. intervention 2: Subjects will undergo three diet periods of 21 days each separated by 7 day washouts. Food will be supplied by a metabolic kitchen and will consist of a phytosterol-deficient baseline diet. During each period subjects will receive either phytosterol esters or placebo and ezetimibe or placebo. intervention 3: None

Protocol document: