The Impact of Carbon Monoxide and Altitude on Vascular Function

NCT04928183 | Completed DMC

• 1 other identifier: Pro00096251
• Study Type: interventional
• Target: 19
• Locations: 1 country
• Sites: 1

Brief Summary

The CarMA (Carbon Monoxide and Altitude) Study aims to observe the vascular effects of carbon monoxide exposure at low and high altitudes.

Conditions

Vasodilation; Vasoconstriction

Outcome Measures

Primary Outcomes (3)

• Change in brachial artery diameter (assessed via ultrasound) following release of arterial occlusion

  Change in brachial artery diameter (assessed via ultrasound) following release of arterial occlusion

  15 minutes

• Blood flow within the brachial artery during rhythmic handgrip exercise.

  Blood flow within the brachial artery during rhythmic handgrip exercise.

  15 minutes

• Change in brachial artery conductance following an infusion of phenylephrine

  Change in brachial artery conductance following an infusion of phenylephrine

  5 min

Study Arms (2)

Room Air Rebreathe

SHAM COMPARATOR

Rebreathe protocol will be completed with a room air syringe rather than CO

Drug: Sodium Nitroprusside; Drug: Phenylephrine Hydrochloride

CO Rebreathe

EXPERIMENTAL

Rebreathe protocol will be completed with Carbon Monoxide

Other: Carbon monoxide rebreathe; Drug: Sodium Nitroprusside; Drug: Phenylephrine Hydrochloride

Interventions

Carbon monoxide rebreathe OTHER

Carbon monoxide exposure to increase blood (Carboxyhemoglobin) COHb safely to \~10%

Also known as: Schmidt-Prommer blood volume test

CO Rebreathe

Sodium Nitroprusside DRUG

Bolus Sodium Nitroprusside (SNP) injection for endothelium-independent vasodilation measure

Also known as: Nipride

CO Rebreathe; Room Air Rebreathe

Phenylephrine Hydrochloride DRUG

Bolus Phenylephrine injection for observe α1-mediated vasoconstriction during mild exercise

CO Rebreathe; Room Air Rebreathe

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Between the ages of 18-50 years
• No medical history of cardiovascular, respiratory, nervous system, or metabolic disease.
• Women must be pre-menopausal.

You may not qualify if:

• Participants with any known cardiovascular, respiratory, nervous system, or metabolic disease.
• Having travelled above 2,000m within 1 month of testing at low and high altitude.
• Women who are pregnant, confirmed by a pregnancy test.
• Women who are post-menopausal.
• Participants that are classified as obese (body mass index \> 30 kg/m2).
• Participants who are current daily smokers.
• Participants that are currently taking monoamine (MAO) inhibitors, or tricyclic antidepressants.

Sponsors & Collaborators

• University of Alberta: lead

Study Sites (1)

University of Alberta

Edmonton, Alberta, T6G 2R3, Canada

Location

Related Publications (5)

• Basnyat B. High altitude pilgrimage medicine. High Alt Med Biol. 2014 Dec;15(4):434-9. doi: 10.1089/ham.2014.1088.

  PMID: 25330393 BACKGROUND

• Rezk-Hanna M, Mosenifar Z, Benowitz NL, Rader F, Rashid M, Davoren K, Moy NB, Doering L, Robbins W, Sarna L, Li N, Chang LC, Elashoff RM, Victor RG. High Carbon Monoxide Levels from Charcoal Combustion Mask Acute Endothelial Dysfunction Induced by Hookah (Waterpipe) Smoking in Young Adults. Circulation. 2019 May 7;139(19):2215-2224. doi: 10.1161/CIRCULATIONAHA.118.037375.

  PMID: 30764644 BACKGROUND

• Choi BG, Lee J, Kim SW, Lee MW, Baek MJ, Ryu YG, Choi SY, Byun JK, Mashaly A, Park Y, Jang WY, Kim W, Choi JY, Park EJ, Na JO, Choi CU, Lim HE, Kim EJ, Park CG, Seo HS, Oh DJ, Rha SW. The association of chronic air pollutants with coronary artery spasm, vasospastic angina, and endothelial dysfunction. Coron Artery Dis. 2018 Jun;29(4):336-343. doi: 10.1097/MCA.0000000000000603.

  PMID: 29334505 BACKGROUND

• Weber LP, Al-Dissi A, Marit JS, German TN, Terletski SD. Role of carbon monoxide in impaired endothelial function mediated by acute second-hand tobacco, incense, and candle smoke exposures. Environ Toxicol Pharmacol. 2011 May;31(3):453-9. doi: 10.1016/j.etap.2011.02.008. Epub 2011 Feb 26.

  PMID: 21787716 BACKGROUND

• Tymko MM, Tremblay JC, Bailey DM, Green DJ, Ainslie PN. The impact of hypoxaemia on vascular function in lowlanders and high altitude indigenous populations. J Physiol. 2019 Dec;597(24):5759-5776. doi: 10.1113/JP277191. Epub 2019 Nov 28.

  PMID: 31677355 BACKGROUND

MeSH Terms

Conditions

Aneurysm

Interventions

Nitroprusside; Phenylephrine

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Intervention Hierarchy (Ancestors)

Ferricyanides; Cyanides; Anions; Ions; Electrolytes; Inorganic Chemicals; Ferric Compounds; Iron Compounds; Hydrogen Cyanide; Nitrogen Compounds; Ethanolamines; Amino Alcohols; Alcohols; Organic Chemicals; Amines

Study Officials

• Sean van Diepen, MD, MSc

  University of Alberta

  PRINCIPAL INVESTIGATOR

• Craig Steinback, PhD

  University of Alberta

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participant will not be aware of which rebreathe treatment (CO or Room Air) they are receiving.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Participants will partake in both room air and CO exposure on 2 separate visits.

Study Record Dates

• First Submitted: May 6, 2021
• First Posted: June 16, 2021
• Study Start: June 10, 2021
• Primary Completion: August 1, 2021
• Study Completion: May 18, 2022
• Last Updated: May 25, 2022

Record last verified: 2021-06

Locations

CA (1)