Study of Dietary N-3 Fatty Acids in Patients With Retinitis Pigmentosa and Usher Syndrome

Retinitis Pigmentosa Clinical Trial

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT00004345
• Other study ID #: 199/11904
• Secondary ID: OHSU-2650
• Status: Terminated
• Phase: N/A
• First received: October 18, 1999
• Last updated: June 23, 2005
• Start date: October 1999

Study information

• Verified date: July 2002
• Source: National Center for Research Resources (NCRR)
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Observational

Clinical Trial Summary

OBJECTIVES: I. Examine the concentration of docosahexanoic acid (DHA) and other n-3 fatty acids in plasma, erythrocyte, and adipose tissue in patients with various forms of retinitis pigmentosa and Usher syndrome.

II. Determine the synthesis and catabolism of DHA from linolenic acid in these patients.

III. Determine the synthesis, absorption, and catabolism of DHA under different dietary conditions in these patients.

Description:

PROTOCOL OUTLINE: Patients may participate in one or more of the arms of this study.

Arm I (adipose tissue study): Adipose tissue is collected from the buttocks of patients with Usher II retinitis pigmentosa (RP), patients with non-Usher RP, and control subjects. Dietary histories are obtained from all patients and subjects.

Arm II (isotope study): Patients meeting the same criteria as in arm I receive oral D5-labeled linolenic acid and oral D4-labeled linolenic acid that is dissolved in oil and incorporated into foods. Subjects must avoid eating fish and shellfish during the 35 days of the isotope study. Blood samples are collected at 0, 8, 24, and 48 hours, daily on days 3-7, and then on days 10, 18, and 35.

Arm III (flaxseed oil feeding): Patients with all types of RP and control subjects receive flaxseed oil, a form of linolenic acid, for 12 weeks. Subjects may also receive high oleic safflower oil or olive oil as a control fat for 12 weeks. Subjects complete a diet history at the end of each fatty acid supplementation period. All subjects must follow a diet free of seafood and fish oil supplements.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 100
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: N/A and older

Eligibility

PROTOCOL ENTRY CRITERIA:

• Retinitis pigmentosa, including: Usher syndrome (types I and II) Simplex

• The following inheritance patterns eligible: X-linked recessive; Autosomal dominant; Autosomal recessive

Study Design

Primary Purpose: Screening

Related Conditions & MeSH terms

• Retinitis
• Retinitis Pigmentosa
• Usher Syndrome
• Usher Syndromes

Locations

Country	Name	City	State
United States	Oregon Health Sciences University	Portland	Oregon

Sponsors (2)

Lead Sponsor	Collaborator
National Center for Research Resources (NCRR)	Oregon Health and Science University

Country where clinical trial is conducted

United States,