The Effect of Viscous Dietary Fibers on LDL-cholesterol

The Effect of Viscous Dietary Fibers on LDL-cholesterol: A Systematic Review and Meta-analysis of Randomized Controlled Trials

This systematic review and meta-analysis is aimed to assess the effect of commonly consumed viscous fibers on blood lipids including LDL-C, non-HDL-C, and ApoB.

Study Overview

• Status: Unknown
• Conditions: Hypercholesterolemia; Cardiovascular Risk Factor
• Intervention / Treatment: Dietary supplement: viscous fiber

Detailed Description

Medline, Embase, CINAHL, and the Cochrane Central databases were searched through May 13, 2019. Three independent reviews extracted data and assessed risk of bias. Randomized controlled trials that assessed the effect of barley b-glucan, oat b-glucan, konjac glucomannan (KJM), psyllium, guar gum, and pectin, with a study duration of ≥ 3 weeks, in adults with or without hypercholesterolemia were included. Data were pooled using the generic inverse variance method with random effects models and expressed as mean differences with 95% confidence intervals. Heterogeneity was assessed by the Cochran Q statistic and quantified by I2 statistic. Overall quality of the evidence was assessed using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) approach.

• Study Type: Observational
• Enrollment (Actual): 7845

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5C 2T2
      • Clinical Risk Factor and Modification Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Hypercholesterolemic or normocholesterolemic adults, overweight and obese individuals or individuals with diabetes

Description

Inclusion Criteria:

• Must be a randomized controlled clinical trial with either a parallel or cross-over design
• have a treatment period of at least 3 weeks
• Hypercholesterolemic or normocholesterolemic adults, overweight and obese individuals or individuals with diabetes were all acceptable
• Sources from β-glucan oats, β-glucan barley, konjac, psyllium, guar gum, and pectin were accepted
• The amount of soluble fiber must be reported or measured or must be computable.
• Must be appropriately controlled.
• Must measure one of LDL-C, non-HDL-C or ApoB. These lipid measures can be either primary or secondary outcomes.
• Enough information must be provided to calculate the magnitude of effect, i.e. end of treatment measures and/or change from baseline measures

Exclusion Criteria:

• If the study was insufficiently controlled, i.e. the control was another soluble fiber
• If the soluble fiber was a combination supplement or in whole food sources where the amount of soluble fiber could not be isolated
• If the outcome measures did not include LDL-C, non-HDL-C or ApoB
• If the treatment period was less than 3 weeks
• If the study was from a non-adult population
• If the study provided insufficient information to calculate a magnitude of effect
• Secondary information such as reviews, editorials, commentaries, were excluded
• If the dose was less than 0.4g/day

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Other

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
LDL-Cholesterol	≥ 3 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
non-HDL-Cholesterol	≥ 3 weeks
ApoB	≥ 3 weeks

Collaborators and Investigators

• Sponsor: Unity Health Toronto

Study record dates

Study Major Dates

• Study Start (Actual): September 17, 2018
• Primary Completion (Anticipated): December 1, 2019
• Study Completion (Anticipated): January 1, 2020

Study Registration Dates

• First Submitted: June 24, 2019
• First Submitted That Met QC Criteria: October 16, 2019
• First Posted (Actual): October 21, 2019

Study Record Updates

• Last Update Posted (Actual): October 21, 2019
• Last Update Submitted That Met QC Criteria: October 16, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Keywords: viscous fiber; barley b-glucan; oat b-glucan; konjac glucomannan; psyllium; guar gum; pectin
• Additional Relevant MeSH Terms: Metabolic Diseases; Lipid Metabolism Disorders; Hyperlipidemias; Dyslipidemias; Hypercholesterolemia
• Other Study ID Numbers: Viscous fiber on LDL-C

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No