Clinical Trial Details
— Status: Active, not recruiting
Administrative data
| NCT number |
NCT05638061 |
| Other study ID # |
CIHR - Soy and BP |
| Secondary ID |
|
| Status |
Active, not recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
October 1, 2022 |
| Est. completion date |
December 1, 2024 |
Study information
| Verified date |
May 2024 |
| Source |
University of Toronto |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Hypertension is one of the leading risk factors for death and significantly increases the
risk for cardiovascular (CVD), brain and kidney diseases. It is also one of the leading
modifiable risk factors for CVD, which also plays a significant role in the global burden of
death and disease. Dietary guidelines for blood pressure management and hypertension
emphasize fruits and vegetables, plant-based proteins and foods low in saturated fat. With
the growing interest in plant-based alternatives and plant-based diets, there is a need to
clarify their benefits on blood pressure. Soy protein is a complete protein and is the only
plant-based beverage alternative that is comparable to dairy milk. There are mixed findings
on the effects of soy on blood pressure due to differences in study design and subjects. To
better address this question and inform public health guidelines the investigators will
conduct a systematic review and meta-analysis of randomized controlled trials of the effect
of soy protein on reducing blood pressure in individuals with and without hypertension.
Description:
RATIONALE: Hypertension is one of the leading risk factors for death and significantly
increases the risk for cardiovascular disease (CVD), brain and kidney diseases. It is also
one of the leading modifiable risk factors for CVD. Dietary guidelines for blood pressure
management and hypertension emphasize fruits and vegetables, plant-based proteins and foods
low in saturated fat. With the growing interest in plant-based alternatives and plant-based
diets, there is a need to clarify their benefits on blood pressure. Soy protein is a complete
protein and is the only plant-based beverage alternative that is comparable to dairy milk.
There are mixed findings on the effects of soy on blood pressure due to differences in study
design and subjects. To better address this question and inform public health guidelines the
investigators will conduct a systematic review and meta-analysis of randomized controlled
trials of the effect of soy protein on reducing blood pressure in individuals with and
without hypertension.
OBJECTIVES: To conduct a systematic review of the effect of soy protein by food source on
systolic (SBP) and diastolic (DBP) blood pressure in individuals with and without
hypertension and assess the certainty of the evidence using the Grading of Recommendations
Assessment Development and Evaluation (GRADE) system.
DESIGN: The systematic review and meta-analyses 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).
DATA SOURCES: Medline, Embase, and The Cochrane Central Register of Controlled Trials
(Clinical Trials; CENTRAL) will be searched using appropriate search terms supplemented by
manual searches of references of included studies.
STUDY SELECTION: Randomized controlled trials of ≥3-weeks assessing the effect of soy protein
food sources compared with a suitable non-soy-containing control group on blood pressure will
be included.
DATA EXTRACTION: Two or more investigators will independently extract relevant data. Authors
will be contacted for additional information and any missing data will be computed/imputed
using standard formulae.
RISK OF BIAS: Two or more investigators will independently assess risk of bias using the
Cochrane Risk of Bias Tool. All disagreements will be resolved by consensus.
OUTCOMES: The primary outcomes will be SBP and DBP.
DATA SYNTHESIS: Data will be pooled using the Generic Inverse Variance method for each
outcome. Random effects models will be used even in the absence of statistically significant
between-study heterogeneity, as they yield more conservative summary effect estimates in the
presence of residual heterogeneity. Fixed-effects models will only be used where there is <5
included studies. Paired analyses will be applied for crossover design trials. Heterogeneity
will be assessed (Cochran Q statistic) and quantified (I2 statistic). Sources of
heterogeneity will be explored (if there are >=10 trial comparisons) by sensitivity analyses
and a priori subgroup analyses (dose, soy protein food source, comparator, follow-up,
baseline levels, design, age, health status, funding and risk of bias). Meta-regression
analyses will assess the significance of categorical and continuous subgroups analyses.
Publication bias will be assessed (if there are >=10 trial comparisons) by inspection of
funnel plots and the Egger and Begg tests. Adjustment for evidence of funnel plot asymmetry
or small study effects will be conducted by the Duval and Tweedie trim-and-fill method.
GRADE ASSESSMENT. To assess the certainty of the evidence, the investigators will use the
GRADE system, an evidence-based grading system adopted by >100 organizations
(http://www.gradeworkinggroup.org/). It grades the evidence as high, moderate, low or very
low quality based on the study design and a series of downgrades (risk of bias, imprecision,
inconsistency, indirectness, publication bias) and upgrades (large magnitude of the effect,
dose-response gradient, and attenuation by confounding). The investigators will follow the
GRADE handbook (https://gdt.gradepro.org/app/handbook/handbook.html) and use the GRADEpro GDT
(gradepro.org) software.
SIGNIFICANCE: The proposed evidence synthesis will assess the role of different food sources
of soy protein for blood pressure management, increasing the evidence-base for health claims
and guidelines development and improving health outcomes, by educating healthcare providers
and patients, stimulating industry innovation, and guiding future research design.
