NCT04928183

The Impact of Carbon Monoxide and Altitude on Vascular Function

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 19 (actual)
• Sponsor: University of Alberta · Academic / Other
• Sex: All
• Age: 18 Years – 50 Years
• Healthy volunteers: Accepted

Summary

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

Detailed description

Each year, millions of people make journeys from low altitude regions to high altitude for recreation, travel, and religious pilgrimage. Carbon monoxide (CO) is commonly associated with cigarette smoke, exhaust fumes, and is viewed as a life-threatening toxic gas. Exposure to CO occurs during travel to and during activities common in high-altitude travel and pilgrimage including vehicle fumes, incense, and second-hand smoke exposure. High altitude exposure and CO exposure have been observed independently to have complex and opposing effects on vascular endothelial function. Observation of these stimuli together in a controlled environment may allow for further understanding of the underlying mechanisms of vascular physiology and adaptations to both high-altitude and CO exposure. The CarMA (Carbon Monoxide and Altitude) Study aims to observe the vascular effects of carbon monoxide exposure at low and high altitudes. Recently, other studies have showed a significant improvement in flow mediated dilation (FMD) with acute exposure to low levels of CO To date, no research has been presented concerning the effect of CO on vascular function at altitude. The present study aims to observe the effect of acute carbon monoxide exposure on 1) flow mediated dilation, 2) conduit artery flow in exercise induced reactive hyperemia at sea level and at altitude, and 3) the effect of CO on vascular function in a high altitude dwelling (sherpa) population.

Conditions

• Vasodilation
• Vasoconstriction

Interventions

Type	Name	Description
OTHER	Carbon monoxide rebreathe	Carbon monoxide exposure to increase blood (Carboxyhemoglobin) COHb safely to \~10%
DRUG	Sodium Nitroprusside	Bolus Sodium Nitroprusside (SNP) injection for endothelium-independent vasodilation measure
DRUG	Phenylephrine Hydrochloride	Bolus Phenylephrine injection for observe α1-mediated vasoconstriction during mild exercise

Timeline

• Start date: 2021-06-10
• Primary completion: 2021-08-01
• Completion: 2022-05-18
• First posted: 2021-06-16
• Last updated: 2022-05-25

Locations

1 site across 1 country: Canada