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Sponsored by: |
University of Cologne |
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Information provided by: | University of Cologne |
ClinicalTrials.gov Identifier: | NCT00654862 |
Intake of cocoa-containing foods has been found to lower blood pressure (BP) in several clinical trials. It is supposed that the cocoa polyphenols represent the active principle, lowering BP by increasing the formation of vasodilative nitric oxide. However, direct evidence for this assumption from controlled clinical studies is lacking. Moreover, in hypertensive subjects vascular dilation appears to be impaired due to endothelial dysfunction and vascular smooth muscle remodeling, but it is unclear whether the BP response to cocoa phenols differs between subjects with high blood pressure and optimal blood pressure.
We hypothesized that (1) intake of cocoa phenols cause a dose-dependent, acute elevation of circulating bioactive NO levels and a reduction in BP, and that (2) the NO elevation and BP reduction are impaired in patients with hypertension.
To test this hypothesis, we will conduct a prospective, randomized, placebo-controlled, double-blind, sample size-calculated, three-period crossover study with pre-planned statistical analysis and trial monitoring, in which cocoa phenols will be orally administered to subjects with mild essential hypertension or subjects with optimal blood pressure. The effects on blood pressure, heart rate and plasma levels of cocoa phenols, circulating bioactive nitric oxide, and plasma markers of oxidative stress will be evaluated. After a 7-day cocoa-free run-in period and a 12-hour overnight fast, 48 subjects (24 with hypertension and 24 sex-, and age (+/- 2yrs)-matched subjects with optimal blood pressure) will receive either a single dose of 1000 mg cocoa polyphenols, 250 mg cocoa phenols or placebo (in capsules of equal form and weight). Each intervention will be followed by a 7-day cocoa-free washout period before cross-over to the subsequent intervention. Subjects will be allocated to the intervention sequence by permuted block randomization (i.e. permuted blocks of 2 subjects with high BP and 2 subjects with optimal BP each, are assigned to permutations of the tree interventions). Measurements of hemodynamic and plasma parameters will be performed directly before and 30, 60, 90, 120, 180, 300, and 480 min after capsule administration. Included subjects will be counseled to maintain their usual diet and physical activity and to abstain from all cocoa products during the study. Analysis of the data will be performed on an intention-to-treat basis.
Condition | Intervention | Phase |
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Hypertension |
Dietary Supplement: cocoa polyphenols |
Phase I |
Study Type: | Interventional |
Study Design: | Treatment, Randomized, Double Blind (Subject, Investigator, Outcomes Assessor), Placebo Control, Crossover Assignment, Efficacy Study |
Official Title: | Randomized Controlled, Double-Blind, Sample Size-Calculated, Three-Period Crossover, Phase 1 Study to Investigate the Efficacy of a Single Oral Dose of Cocoa Phenols on Blood, Pressure, Heart Rate and Plasma Levels of Phenols, Bioactive Nitric Oxide and Oxidation Markers in Subjects With Stage 1 Essential Hypertension and Optimal Blood Pressure |
Enrollment: | 48 |
Study Start Date: | October 2007 |
Estimated Primary Completion Date: | May 2008 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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1: Experimental
Subjects with stage 1 hypertension
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Dietary Supplement: cocoa polyphenols
Oral administration of capsules with 1000 mg polyphenols, 250 mg polyphenols or placebo
|
2: Experimental
Subjects with optimal blood pressure
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Dietary Supplement: cocoa polyphenols
Oral administration of capsules with 1000 mg polyphenols, 250 mg polyphenols or placebo
|
Ages Eligible for Study: | 50 Years to 75 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Exclusion Criteria:
Germany | |
Department of Pharmacology, University of Cologne | |
Cologne, Germany, D-50931 |
Principal Investigator: | Dirk Taubert, MD, PhD | University of Cologne |
Responsible Party: | University of Cologne ( Dirk Taubert ) |
Study ID Numbers: | ECA-02-006 |
Study First Received: | April 3, 2008 |
Last Updated: | April 3, 2008 |
ClinicalTrials.gov Identifier: | NCT00654862 |
Health Authority: | Germany: Federal Institute for Drugs and Medical Devices |
Nitric Oxide Vascular Diseases Essential hypertension Hypertension |
Cardiovascular Diseases |