Acute Hemodynamic Effects of Cocoa Polyphenols in Subjects With Hypertension and Optimal Blood Pressure
Condition: Hypertension
MeSH terms: Hypertension
Study type: Interventional
Phase: Phase 1

Summary: 
      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.

      The investigators 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, the investigators 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, arterial function 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.
    


Intervention name(s): cocoa polyphenols; cocoa polyphenols
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Oral administration of capsules with 1000 mg polyphenols, 250 mg polyphenols or placebo; Oral administration of capsules with 1000 mg polyphenols, 250 mg polyphenols or placebo
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment