7007: Effects of Fish Oil, Colesevelam, and Combination Therapy on Sterol Metabolism in Sitosterolemia


Study Summary

For Diseases: Sitosterolemia Background

Sitosterolemia is an inherited condition in which plant sterols (chemicals from plants) are not broken down properly in the body. In sitosterolemia, plant sterols build up, causing damage to body tissues.

Ezetimibe is a drug that is often used to treat sitosterolemia. Ezetimibe reduces the amount of cholesterol (a fat-like substance) and plant sterol in the blood. However, plant sterol levels remain very high compared to those in people without sitosterolemia. We want to see if ezetimibe combined with other treatments will further lower blood levels of plant sterol in sitosterolemia patients more than ezetimibe on its own.

Colesevelam is a drug that is used to help lower cholesterol. The purpose of this study is to see if combining ezetimibe with colesevelam will lower blood levels of plant sterol and cholesterol in sitosterolemia patients.

Fish oil is popularly used to help lower cardiovascular risk factors. Therefore, a second purpose of this study is to see if fish oil has any health benefits in patients with sitosterolemia. The results of this study will help us to learn more about how sitosterolemia develops and how colesevelam and fish oil work in patients with the disease.

About this Study

This is a pilot interventional study of 16 participants. The purpose of the study is to learn more about how colesevelam and fish oil change plant sterol and cholesterol levels when used in combination with ezetimibe for patients with sitosterolemia.

After consent, study participants will be followed for 6 weeks on ezetimibe. After these 6 weeks, participants will be asked to take colesevelam and ezetimibe for 6 weeks. This will be followed by 4 weeks back on ezetimibe by itself, then by 6 weeks on fish oil and ezetimibe. Finally, there will be 4 weeks back on only ezetimibe followed by 6 weeks on colesevelam + fish oil + ezetimibe.

During all phases of the study, participants will be asked to:

  • Keep a log of what they eat
  • Talk to the study coordinator about what is they eaten
  • Have a physical exam
  • Give blood (up to 4 teaspoons per session)
  • Give urine sample (some visits)

Targeted Enrollment

You are eligible to participate if:

  • You have a confirmed diagnosis of homozygous sitosterolemia as established by genotyping and/or clinical parameters.
  • You are age 8 years and older.

You are not eligible to participate if:

  • You are not able to travel to a study site.
  • You are pregnant.
  • You are unwilling or unable to comply with study procedures.
  • You are unwilling or unable to give consent to participate.

How to participate:

In order to participate in a study, you must personally contact the study coordinator, please contact:

University of Manitoba
Semone Myrie, RD, PhD
Study Coordinator