Clinical trial NCT04133805: The Effect of Viscous Dietary Fibers on LDL-cholesterol
Official title: The Effect of Viscous Dietary Fibers on LDL-cholesterol: A Systematic Review and Meta-analysis of Randomized Controlled Trials
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Cardiovascular Risk Factor
Hypercholesterolemia
Keywords: viscous fiber
barley b-glucan
oat b-glucan
konjac glucomannan
psyllium
guar gum
pectin
Lead sponsor: Unity Health Toronto
Sponsor class: OTHER
First posted: 2019-10-21
Enrollment: 7845
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: OTHER
Time perspective: OTHER
Sampling method: PROBABILITY_SAMPLE
Study population: Hypercholesterolemic or normocholesterolemic adults, overweight and obese individuals or individuals with diabetes

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: LDL-Cholesterol
timeFrame: ≥ 3 weeks
Secondary outcomes:
measure: non-HDL-Cholesterol
timeFrame: ≥ 3 weeks
measure: ApoB
timeFrame: ≥ 3 weeks
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Clinical Risk Factor and Modification Centre
state: Ontario
Study officials:
References: