Biodiesel Exhaust, Acute Vascular and Endothelial Responses - Full Text View

Purpose

Exposure to particulate air pollution has been shown to increase cardiovascular mortality and morbidity, and in previous controlled exposure studies has been shown to have acute cardiovascular and respiratory effects. The last decade has seen an unprecedented drive towards finding a bioeconomical and renewable source of fuel in order to reduce our dependence on fossil fuels. Although both biodiesel and bioethanol have emerged as contenders for future fuels, biodiesel remains as the strongest contender within European markets. In 2007 researchers at the EPA released a commentary, which concluded that the assumed correlation between the chemical composition of biodiesel exhaust and a reduction in health effects was only hypothetical. They suggested that there was a clear need for the study of health effects in humans regarding biofuel exhaust. In this project the investigators aim to investigate the cardiovascular, respiratory and inflammatory responses to biofuel exhaust exposure in healthy volunteers.

Condition	Intervention
Healthy	Other: Forearm venous occlusion plethysmography study

Study Type:	Interventional
Study Design:	Allocation: Randomized Intervention Model: Crossover Assignment Masking: Double Blind (Subject, Investigator, Outcomes Assessor) Primary Purpose: Basic Science
Official Title:	Inhalation of Dilute Biodiesel Exhaust: Acute Vascular and Endothelial Responses

Resource links provided by NLM:

MedlinePlus related topics: Air Pollution

U.S. FDA Resources

Further study details as provided by University of Edinburgh:

Primary Outcome Measures:

Vascular vasomotor and fibrinolytic function [ Time Frame: 4-6 hours after exposure ] [ Designated as safety issue: No ]
Forearm venous occlusion plethysmography to measure forearm blood flow during unilateral intrabrachial infusion of endothelial-dependent (bradykinin and acetylcholine) and -independent (sodium nitroprusside and verapamil) vasodilators. Fibrinolytic function assessed by blood sampling after infusion of bradykinin for tissue plasminogen activator and plasminogen activator inhibitor-1.

Secondary Outcome Measures:

Respiratory function tests [ Time Frame: 6 hours after exposure ] [ Designated as safety issue: No ]
Basic spirometry will be performed at baseline and 6 hours after each exposure
Inflammatory markers [ Time Frame: Baseline and up to 24 hours after exposure ] [ Designated as safety issue: No ]
Blood samples will be taken and stored as plasma and serum for measurement of inflammatory mediators
Central arterial stiffness [ Time Frame: Baseline and post exposure ] [ Designated as safety issue: No ]
Central arterial stiffness (PWV and PWA) will be measured at baseline and immediately after the exposure

Enrollment:	16
Study Start Date:	April 2011
Study Completion Date:	November 2011
Primary Completion Date:	July 2011 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
Experimental: Diesel exhaust exposure 1 hour exposure to dilute diesel exhaust (approximate PM10 concentration 300 mcg/m3) during intermittent exercise	Other: Forearm venous occlusion plethysmography study Forearm venous occlusion plethysmography to measure forearm blood flow during unilateral intrabrachial infusion of endothelium-dependent (bradykinin [100, 300 & 1000 pmol/min]; acetylcholine [5, 10 & 20 µg/min]) and -independent [sodium nitroprusside [2, 4 & 8 µg/min]; verapamil [10, 30 & 100 µg/min]) vasodilators. Each drug to be infused for 6 mins at each dose in increasing concentrations. 0.9% sodium chloride will be infused for 20 min between each individual drug to allow washout.
Experimental: Biodiesel exhaust exposure 1 hour exposure to dilute biodiesel exhaust (approximate PM10 concentration 300 mcg/m3) during intermittent exercise	Other: Forearm venous occlusion plethysmography study Forearm venous occlusion plethysmography to measure forearm blood flow during unilateral intrabrachial infusion of endothelium-dependent (bradykinin [100, 300 & 1000 pmol/min]; acetylcholine [5, 10 & 20 µg/min]) and -independent [sodium nitroprusside [2, 4 & 8 µg/min]; verapamil [10, 30 & 100 µg/min]) vasodilators. Each drug to be infused for 6 mins at each dose in increasing concentrations. 0.9% sodium chloride will be infused for 20 min between each individual drug to allow washout.

Arms

Assigned Interventions

Experimental: Diesel exhaust exposure

1 hour exposure to dilute diesel exhaust (approximate PM10 concentration 300 mcg/m3) during intermittent exercise

Other: Forearm venous occlusion plethysmography study

Forearm venous occlusion plethysmography to measure forearm blood flow during unilateral intrabrachial infusion of endothelium-dependent (bradykinin [100, 300 & 1000 pmol/min]; acetylcholine [5, 10 & 20 µg/min]) and -independent [sodium nitroprusside [2, 4 & 8 µg/min]; verapamil [10, 30 & 100 µg/min]) vasodilators. Each drug to be infused for 6 mins at each dose in increasing concentrations. 0.9% sodium chloride will be infused for 20 min between each individual drug to allow washout.

Experimental: Biodiesel exhaust exposure

1 hour exposure to dilute biodiesel exhaust (approximate PM10 concentration 300 mcg/m3) during intermittent exercise

Other: Forearm venous occlusion plethysmography study

Forearm venous occlusion plethysmography to measure forearm blood flow during unilateral intrabrachial infusion of endothelium-dependent (bradykinin [100, 300 & 1000 pmol/min]; acetylcholine [5, 10 & 20 µg/min]) and -independent [sodium nitroprusside [2, 4 & 8 µg/min]; verapamil [10, 30 & 100 µg/min]) vasodilators. Each drug to be infused for 6 mins at each dose in increasing concentrations. 0.9% sodium chloride will be infused for 20 min between each individual drug to allow washout.

Eligibility

Ages Eligible for Study:	20 Years to 55 Years
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

20 healthy, non-smoking subjects, age 20-55 year old, both genders.

All subjects undergo a general health examination and are required to have:

Normal clinical examination Normal EKG Normal routine blood tests Normal lung function

Exclusion Criteria:

Cardiovascular disease
Diabetes Mellitus
Asthma and/or allergy
Respiratory infection within 3 weeks of the study
Antioxidant- and/or vitamin supplementation within 2 weeks prior to, as well as during the course of the study. (incl vitamin C, Acetylcysteine)
Female subjects will take a urinary pregnancy test before each exposure and will be excluded if this is positive.

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT01337882

Locations

Sweden
Umeå University Hospital
Umeå, Sweden, 901 85

Sponsors and Collaborators

University of Edinburgh

Umeå University

Investigators

Principal Investigator:

Jenny A Bosson Damewood, MD PhD

Umeå University

More Information

No publications provided

Responsible Party:	Jeremy Langrish, Clinical Lecturer and Specialty Registrar in Cardiology, University of Edinburgh
ClinicalTrials.gov Identifier:	NCT01337882 History of Changes
Other Study ID Numbers:	BEAVER
Study First Received:	April 15, 2011
Last Updated:	November 30, 2011
Health Authority:	Sweden: Regional Ethical Review Board

Keywords provided by University of Edinburgh:

Air Pollution
Diesel exhaust
Biodiesel exhaust

Vascular function
Fibrinolysis
Acute vascular and endothelial responses

ClinicalTrials.gov processed this record on May 19, 2013

Biodiesel Exhaust, Acute Vascular and Endothelial Responses (BEAVER)