Effects of Altitude on Single-Breath Diffusing Capacity for Carbon Monoxide (DLCO)

Effects of Altitude on Single-Breath Diffusing Capacity for Carbon Monoxide in Normal Subjects and Chronic Obstructive Pulmonary Disease

The purpose of this study is to further understand the effects of altitude on the physiology of gas exchange in the pulmonary microcirculation in normal subjects and in people with chronic obstructive pulmonary disease (COPD) measured as the single-breath diffusing capacity for carbon monoxide (DLCOsb). The study will determine a mathematical formula to allow for altitude corrections in both study populations to be used clinically in pulmonary labs.

Study Overview

• Status: Completed
• Conditions: COPD

Detailed Description

The DLCOsb is one of the most common and widely tests clinically used across the world in pulmonary function laboratories to assess gas exchange from the lung to hemoglobin in the pulmonary circulation. This test is used in the differential diagnosis of respiratory related symptoms, to grade the degree of severity in lung disease, and to objectively monitor the progression of disease or the response to therapies. Therefore, it is important to have standard methods of performing and interpreting this test.This is a prospective study, collecting data from subjects at different simulated altitudes. The study hypothesis is that increasing altitude will increase the DLCOsb in a predictable manner that will allow for mathematical corrections to be applied for uniform interpretation in pulmonary labs at differing altitudes.

• Study Type: Observational
• Enrollment (Actual): 23

Contacts and Locations

Study Locations

• United States
  • Utah
    • Murray, Utah, United States, 84157
      • Intermountain Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Men and women, ages 20-80, both healthy subjects and those with a diagnosis of COPD.

Description

Inclusion Criteria:

• Ages 20- 80 years
• Subjects must be either healthy or have been diagnosed with COPD

Exclusion Criteria:

• Anemia (hemoglobin < 10.0 g/dL)
• Carboxyhemoglobin > 3%
• Active smoking
• Heart disease or heart failure
• Pulmonary hypertension
• COPD exacerbation
• Pneumothroax within 6 months
• Bullous emphysema on chest imaging (Chest X-ray or CT)
• Supplemental oxygen use
• Diabetes mellitus
• Alcohol dependence
• Non-English speaking

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Healthy subjects
Subjects with COPD; Subjects with a diagnosis of COPD

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Effect of altitude on measured diffusing capacity for carbon monoxide	3 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Comparison of a novel inert gas technique for measuring alveolar volume with body plethysmography	4 months

Collaborators and Investigators

• Sponsor: Intermountain Health Care, Inc.
• Collaborators: University of Utah
• Investigators: Principal Investigator: Matt Hegewald, MD, Intermountain Health Care, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): August 10, 2017
• Primary Completion (Actual): June 15, 2018
• Study Completion (Actual): July 1, 2019

Study Registration Dates

• First Submitted: July 28, 2017
• First Submitted That Met QC Criteria: July 28, 2017
• First Posted (Actual): August 1, 2017

Study Record Updates

• Last Update Posted (Actual): February 12, 2020
• Last Update Submitted That Met QC Criteria: February 11, 2020
• Last Verified: February 1, 2020

More Information

Terms related to this study

• Keywords: COPD; Pulmonary function testing; Altitude; Diffusing capacity for carbon monoxide
• Other Study ID Numbers: DLCO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No