Abstract:
INTRODUCTION : Patients with type 2 diabetes mellitus are at high risk to develop vascular
complications resulting in high morbidity and mortality. Cocoa flavanols are promising
nutraceuticals with possible beneficial vascular effects in humans. However, limited
research is currently available on the vascular effects in a diabetic population with
inconsistent results. Possible reasons for this inconsistency might be heterogeneity
in the given intervention (dose per time and day, single dose vs. split-dose, placebo
formula) and the studied population (blood pressure at baseline, duration of diabetes,
use of vasoactive antihypertensive and antidiabetic drugs, sex). Therefore, we aimed to
develop a randomized, double-blinded, placebo-controlled cross-over trial to investigate
whether cocoa flavanols have an acute impact on blood pressure and vascular reactivity
in patients with type 2 diabetes with and without arterial hypertension.
METHODS AND ANALYSIS : We will include participants in four groups: (i) patients
with type 2 diabetes without arterial hypertension, (ii) patients with type 2 diabetes
with arterial hypertension and 1 antihypertensive drug, (iii) non-diabetic participants
with essential hypertension and 1 antihypertensive drug, and (iv) healthy controls.
All participants will complete the same protocol on both testing days, consuming
high-flavanol cocoa extract (790mg flavanols) or placebo. Macrovascular endothelial
function (flow-mediated dilation) and blood pressure will be measured before and
after capsule ingestion. Forearm muscle vasoreactivity (near-infrared spectroscopy) and brachial artery blood flow (echo-doppler) will be assessed in response to a dynamic
handgrip exercise test after capsule ingestion. Data will be analyzed with a random
intercept model in mixed models.
