Effect of Polyphenols on Peripheral Vascular Disease.

Effect of Dark Chocolate on Endothelial Function and Oxidative Stress in Patients With Peripheral Vascular Disease.

Peripheral arterial disease (PAD) is a clinical setting characterized by an exceptionally high risk for cardiovascular events. Oxidative stress seems to play a role in impairing flow-mediated dilation (FMD) and contributing to atherosclerosis in patients with PAD. Cocoa seems to exert artery dilatation via oxidative stress inhibition.

OBJECTIVES: To investigate whether in PAD patients, dark chocolate elicits artery dilatation via down-regulation of NOX2, the catalytic core of NADPH oxidase.

Study Overview

• Status: Completed
• Conditions: Peripheral Arterial Disease
• Intervention / Treatment: Dietary supplement: milk chocolate with crossover to dark chocolate; Dietary supplement: dark chocolate with crossover to milk chocolate

Detailed Description

Atherosclerosis represents the major cause of worldwide death; it is a complex phenomenon that encompasses the intricate interplay of classic cardiovascular risk factors, oxidative stress and inflammation.

Peripheral artery disease (PAD) is a clinical setting that well represents the model of widespread atherosclerosis. PAD affects 20% of patients over the age of 75. Furthermore, PAD patients are at an exceptionally high risk for cardiovascular events and the majority will eventually die of a cardiac or cerebrovascular etiology.

Polyphenol could represent a novel therapeutic strategy to counteract atherosclerosis. During the last decades, a growing interest in polyphenols resulted from prospective and epidemiological studies that showed the beneficial effects of these substances on human health. In particular, polyphenols exert their beneficial effect by inhibition of NADPH oxidase (NOX2), an enzyme directly involved in atherosclerosis; thus, the activation of this enzyme leads to an enhanced production of oxidative stress and inflammatory processes.

The objective of this study is to evaluate the effect of polyphenols on oxidative stress and inflammation and on surrogate markers of atherosclerosis in PAD patients. Polyphenols, inhibiting NOX2-mediated oxidative stress and immune-mediated process, could represent a novel therapy to reduce the high risk of cardiovascular events in PAD.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 2; Phase 1

Contacts and Locations

Study Locations

• Italy
  • Rome, Italy, 00161
    • Sapienza University of Rome, I Clinica Medica, Research Tower

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Every PAD patient to be enrolled in the study had:

1. claudication (defined as leg pain on walking, disappearing within 10 minutes of standing, of presumed atherosclerotic origin) and
2. ankle/brachial index (ABI), that was assessed as ankle/arm systolic blood pressure ratio by Doppler ultrasonography <0.90 on the worst leg at rest.

Patients had to be in stable conditions without abrupt changes of ABI (>20%) in the last month before the enrolment.

Exclusion Criteria:

Subjects were excluded from the study if they had liver insufficiency, serious renal disorders (serum creatinine>2.8 mg/dL), acute stroke, acute myocardial infarction, deep venous thrombosis or if they were current smokers or were taking antioxidants.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: milk chocolate; dosage form: orally given dosage:40 g milk chocolate (≤35% cocoa) frequency and duration: 40 g/day for one month	Dietary supplement: milk chocolate with crossover to dark chocolate; 40 g/d of milk chocolate for 4 weeks followed by wash-out (1 week) and by 40 g/d of dark chocolate for 4 weeks.
Active Comparator: dark chocolate; dosage form: orally given dosage:40 g dark chocolate (≥85% cocoa) frequency and duration: 40 g/day for one month	Dietary supplement: dark chocolate with crossover to milk chocolate; 40 g/d of dark chocolate for 4 weeks followed by wash-out (1 week) and by 40 g/d of milk chocolate for 4 weeks

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
endothelial function assessed by flow mediated dilation (FMD)	2 hours after (dark or milk) chocolate ingestion
endothelial function assessed by flow mediated dilation (FMD)	after 30 days of (dark or milk) chocolate ingestion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxidative stress markers	Oxidative stress markers: sNOX2dp, Isoprostanes, NOx	2 hours after (dark or milk) chocolate ingestion
Maximal walking distance		2 hours after (dark or milk) chocolate ingestion
Ankle Brachial Index (ABI)		2 hours after (dark or milk) chocolate ingestion
Oxidative stress markers	Oxidative stress markers: sNOX2dp, Isoprostanes, NOx	after 30 days of (dark or milk) chocolate ingestion
Maximal walking distance		after 30 days of (dark or milk) chocolate ingestion
Ankle Brachial Index (ABI)		after 30 days of (dark or milk) chocolate ingestion

Collaborators and Investigators

• Sponsor: University of Roma La Sapienza

Publications and helpful links

General Publications

• Loffredo L, Carnevale R, Cangemi R, Angelico F, Augelletti T, Di Santo S, Calabrese CM, Della Volpe L, Pignatelli P, Perri L, Basili S, Violi F. NOX2 up-regulation is associated with artery dysfunction in patients with peripheral artery disease. Int J Cardiol. 2013 Apr 30;165(1):184-92. doi: 10.1016/j.ijcard.2012.01.069. Epub 2012 Feb 14.
• Carnevale R, Loffredo L, Pignatelli P, Nocella C, Bartimoccia S, Di Santo S, Martino F, Catasca E, Perri L, Violi F. Dark chocolate inhibits platelet isoprostanes via NOX2 down-regulation in smokers. J Thromb Haemost. 2012 Jan;10(1):125-32. doi: 10.1111/j.1538-7836.2011.04558.x.
• Loffredo L, Carnevale R, Perri L, Catasca E, Augelletti T, Cangemi R, Albanese F, Piccheri C, Nocella C, Pignatelli P, Violi F. NOX2-mediated arterial dysfunction in smokers: acute effect of dark chocolate. Heart. 2011 Nov;97(21):1776-81. doi: 10.1136/heartjnl-2011-300304. Epub 2011 Jul 31.
• Loffredo L, Perri L, Catasca E, Pignatelli P, Brancorsini M, Nocella C, De Falco E, Bartimoccia S, Frati G, Carnevale R, Violi F. Dark chocolate acutely improves walking autonomy in patients with peripheral artery disease. J Am Heart Assoc. 2014 Jul 2;3(4):e001072. doi: 10.1161/JAHA.114.001072. Erratum In: J Am Heart Assoc. 2014 Aug;3(4):e000456.

Study record dates

Study Major Dates

• Study Start: October 1, 2010
• Primary Completion (Actual): August 1, 2013
• Study Completion (Actual): September 1, 2013

Study Registration Dates

• First Submitted: September 12, 2013
• First Submitted That Met QC Criteria: September 17, 2013
• First Posted (Estimate): September 20, 2013

Study Record Updates

• Last Update Posted (Estimate): September 20, 2013
• Last Update Submitted That Met QC Criteria: September 17, 2013
• Last Verified: September 1, 2013

More Information

Terms related to this study

• Keywords: Oxidative stress; Peripheral arterial disease; polyphenols; Cocoa; NADPH oxidase
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Arteriosclerosis; Arterial Occlusive Diseases; Atherosclerosis; Vascular Diseases; Peripheral Arterial Disease; Peripheral Vascular Diseases
• Other Study ID Numbers: C26A12BPZN (Other Identifier: Sapienza University)