Oat Fiber and Cardiovascular Risk Reduction: A Systematic Review and Meta-analysis of Randomized Controlled Trials
Trial Snapshot
- Phase
- Not Applicable
- Status
- Active, not recruiting
- Sponsor
- University of Toronto
- Enrollment
- 1
- Locations
- 1
- Primary Endpoint
- Framingham Risk Score (FRS)
Study Overview
Brief Summary
Oat fibre has been shown to lower cholesterol and may have cardioprotective effects. However, whether this translates to actual cardiovascular risk reduction is unclear, as there is a lack of controlled human trials. To address this uncertainty, the investigator proposes to use established cardiovascular disease risk scores, such as those recommended by the Canadian Cardiovascular Society and other clinical practice groups, to create composite risk scores in assessing future risk. The data on oat fibre will be collected through a systematic review of controlled trials, composite cardiovascular risk scores will be calculated for each eligible study, and meta-analyses will be conducted to assess the overall effect. The findings generated by this proposed knowledge synthesis will help improve the health of consumers through informing evidence-based guidelines and improving health outcomes by educating healthcare providers and patients, stimulating industry innovation, and guiding future research design.
Detailed Description
Background: Although oat beta-glucan has an approved health claim for cholesterol-lowering in Canada, US, and Europe, it is unclear whether this effect translates into lower cardiovascular disease risk. There is a well-established causal link between LDL-C and cardiovascular disease based on the results of pharmacological interventions that target different LDL-C- lowering mechanisms and mendelian randomization studies. However, there are no randomized controlled trials of the effect of whole grain oats or oat beta-glucan on cardiovascular outcomes and the few prospective cohort studies that have assessed the relation of whole grain oats with cardiovascular outcomes have failed to show a reliable protective association.
One way to confirm the cardiovascular benefit of whole grain oats and oat beta-glucan would be to use an established 10-year cardiovascular disease risk score such as the modified Framingham Risk Score (FRS) (recommended by the Canadian Cardiovascular Society [CCS]), the American College of Cardiology/American Heart Association (ACC/AHA) ASCVD risk estimator (recommended by the ACC/AHA) or Systemic Coronary Risk Estimation (SCORE) (recommended by the European Society of Cardiology [ESC] and European Atherosclerosis Society [EAS]). These scores are composites of cardiovascular risk factors in which cholesterol and blood pressure carry important weight. There are numerous systematic reviews and meta-analyses of randomized trials showing a benefit of whole grain oats and oat beta-glucan for cholesterol and blood pressure. The investigators propose a novel approach to leverage these benefits to detect an overall reduction in 10-year cardiovascular disease by these scores.
Need for proposed research: High quality systematic reviews and meta-analyses of randomized controlled trials represent the highest level of evidence to support dietary guidelines and public health policy development. As dietary guidelines and public health policy have shifted toward food and dietary-pattern based recommendations, there is a need for systematic reviews and meta-analyses on the effect of oats and oat beta-glucan on cardiovascular risk.
Objective: To improve evidence-based guidance for clinical practice guidelines for nutrition therapy and public health policy development, the investigators will conduct a systematic review and meta-analysis of the effects of whole grain oats and oat beta-glucan on 10-year cardiovascular disease risk using (1) the modified Framingham Risk Score, (2) the ASCVD risk estimator, and (3) the SCORE.
Design: The systematic review and meta-analysis will be conducted according to the Cochrane Handbook for Systematic Reviews of Interventions and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).
Study Design
- Study Type
- Observational
- Observational Model
- Other
- Time Perspective
- Prospective
Eligibility Criteria
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Dietary trials in humans
- •Randomized treatment allocation
- •Intervention with oats or oat beta-glucan
- •Suitable control (i.e. isocaloric diet that is not vegetarian or vegan)
- •Ascertainment of viable outcome data for cardiovascular risk calculations
Exclusion Criteria
- •Non-human studies
- •Non-randomized treatment allocation
- •<3 weeks
- •No intervention of oats or oat beta-glucan
- •Lack of a suitable control (i.e. non-isocaloric)
- •No viable endpoint data
Outcomes
Primary Outcomes
Framingham Risk Score (FRS)
Time Frame: >= 3-weeks
Framingham Risk Score (FRS) calculates 10-year cardiovascular risk using the Cox formula which includes age, sex, total cholesterol, HDL-cholesterol, systolic blood pressure, blood pressure medication use, diabetes status, smoking status; minimum score 0%, maximum score 100% where higher score indicates higher risk of 10-year risk of cardiovascular disease
Secondary Outcomes
- Systematic COronary Risk Evaluation (SCORE)(>= 3-weeks)
- ACC/AHA ASCVD risk estimator(>= 3-weeks)
Investigators
John Sievenpiper
Associate Professor
University of Toronto