Heart & Health Study

This study has been completed.
Sponsor:
Collaborators:
University of California, Davis
USDA Beltsville Human Nutrition Research Center
Alta Bates Summit Medical Center
University of Southern California
Information provided by:
USDA, Western Human Nutrition Research Center
ClinicalTrials.gov Identifier:
NCT00536185
First received: September 5, 2007
Last updated: August 3, 2011
Last verified: August 2011
  Purpose

We hope to learn more about why certain people have higher levels of the 5-LO protein and whether taking fish oil supplements gives such individuals greater protection than others against cardiovascular disease. The 5-LO protein is important in the development of heart disease because it converts a type of oil from meat into a compound that can cause inflammation in blood vessels. This inflammation is a major cause of heart disease.

Researchers think that people with higher levels of a protein called 5-LO in their white blood cells may have a healthier response to using fish oil supplements than do people with lower levels of this protein.


Condition Intervention
Heart Disease
Dietary Supplement: Fish Oil
Dietary Supplement: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Variation in the ALOX5 Gene and Response to Omega-3 Fatty Acid Supplements

Resource links provided by NLM:


Further study details as provided by USDA, Western Human Nutrition Research Center:

Primary Outcome Measures:
  • (a) ALOX5 mRNA and protein in resting and stimulated cultures of purified monocytes and purified granulocytes (b) Arachidonic acid-derived leukotrienes in resting and stimulated cultures of whole blood, purified monocytes and purified granulocytes [ Time Frame: 6 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Proinflammatory cytokines, C-reactive protein, triglycerides, glucose and insulin in plasma, and resting heart rate and blood pressure [ Time Frame: 6 weeks ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 166
Study Start Date: December 2006
Study Completion Date: July 2008
Primary Completion Date: July 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1 Dietary Supplement: Fish Oil
capsules, 5.0 g/d fish oil concentrate (3.0 g/d EPA + DHA), 6 weeks
Placebo Comparator: 2 Dietary Supplement: Placebo
capsule, 5.0 g/d corn/soybean oil (50/50 mixture), 6 weeks

Detailed Description:

Fish oil supplements will be given to subjects with different variants in the promoter region of the arachidonate 5-lipoxygenase (ALOX5) gene and outcome measures will be evaluated after 6 wk of supplementation. These outcomes include ALOX5 protein levels (also called 5-lipoxygenase, or 5-LO), leukotriene levels, markers of inflammation, and blood lipids. The 5-LO enzyme converts arachidonic acid (AA) to leukotrienes that promote inflammation. Subjects with different promoter variants are hypothesized to have different basal or stimulated levels of 5-LO expression. Preliminary data suggests that subjects with a promoter variant that causes increased 5-LO expression also may have a "better" anti-inflammatory or lipid-lowering response to fish oil supplements. The homozygous variant genotype is much more common in African Americans than other groups thus we propose to conduct the study in African Americans. The fish oil eicosapentaenoic acid (EPA) competitively inhibits conversion of AA to pro-inflammatory 4-series leukotrienes.

The grant proposes to conduct a community-based, double-masked, randomized, placebo-controlled trial; n = 15/group, total = 166 (genotypes 44 will have n = 8). The intervention group will receive 5.0 g/d fish oil concentrate (3.0 g/d EPA + DHA) for 6 wk. The study will be conducted in Oakland, Davis, and Sacramento, California where African Americans 20 - 59 y of age without serious chronic disease will be recruited.

A recent observational study indicates that subjects with a variant allele for ALOX5 may be at greater risk for cardiovascular disease and, at the same time, may derive a greater benefit from omega-3 fatty acid supplements than do subjects homozygous for the common allele. The variant alleles are less common in the white population (18%) than in the black population (52%). Since African Americans have a higher prevalence of cardiovascular disease and of the ALOX5 variant alleles, as shown in epidemiologic studies, they may have a greater benefit from omega-3 supplementation in the reduction of inflammation and cardiovascular risk factors. Recruitment will be conducted through the community service, Ethnic Health Institute (EHI), of Alta Bates Summit Medical Center in conjunction with UCD, and outreach efforts from the USDA, ARS, Western Human Nutrition Research Center (WHNRC) at UC Davis. We will determine if subjects with one or two variant ALOX5 alleles have higher ALOX5 gene expression, higher production of AA-derived leukotrienes, and a better response to omega-3 supplements than do subjects homozygous for the common allele.

  Eligibility

Ages Eligible for Study:   20 Years to 59 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • African-American, Black, or persons of African Descent
  • Generally Healthy
  • 20 - 59 years of age

Exclusion Criteria:

  • Chronic Diseases (Heart disease, cancer, diabetes, etc.)
  • Smoke > 14 cigarettes per week
  • Consume > 14 alcoholic drinks per week
  • Pregnant Women
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00536185

Locations
United States, California
UC Davis, Western Human Nutrition Research Center
Davis, California, United States, 95616
Ethnich Health Institute
Oakland, California, United States, 94609
UC Davis (TICON-1)
Sacramento, California, United States, 95820
Sponsors and Collaborators
USDA, Western Human Nutrition Research Center
University of California, Davis
USDA Beltsville Human Nutrition Research Center
Alta Bates Summit Medical Center
University of Southern California
Investigators
Principal Investigator: Charles B Stephensen, PhD UC Davis & U.S. Department of Agriculture
  More Information

Additional Information:
No publications provided by USDA, Western Human Nutrition Research Center

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Charles Bolt Stephenson, PhD, Western Human Nutrition Resource Center
ClinicalTrials.gov Identifier: NCT00536185     History of Changes
Other Study ID Numbers: R21 AT003411-01A1, R21AT003411-01A1
Study First Received: September 5, 2007
Last Updated: August 3, 2011
Health Authority: United States: Federal Government

Keywords provided by USDA, Western Human Nutrition Research Center:
ALOX5
5-lipoxygenase
Heart Disease
Blacks

Additional relevant MeSH terms:
Heart Diseases
Cardiovascular Diseases

ClinicalTrials.gov processed this record on August 28, 2014