Long COVID and Post-exertional Pulmonary Diffusion (Long_COVID_Ex)

Lung Diffusing Capacities for Nitric Oxide and Carbon Monoxide in Long COVID With Dyspnea at Rest and After Mild Exercise

Aim of investigators was to study whether abnormalities of lung diffusing capacity for nitric oxide (DLNO) and carbon monoxide (DLCO) in long COVID may have a clinical impact in relation to exercise intolerance.

Study Overview

• Status: Completed
• Conditions: Long COVID; Breathlessness; Exercise Intolerance; Pulmonary Gas Exchange; Alveolar Lung Disease
• Intervention / Treatment: Diagnostic test: Lung volumes, spirometry and standard single-breath DLCO were measured at rest while combined DLNO and DLCO were measured at rest and post-exercise

Detailed Description

Prolonged recovery from acute coronavirus disease 2019 (long COVID) is characterized in about 30% of subjects from breathlessness and fatigue also during daily activities often associated to decreased lung diffusing capacity for carbon monoxide (DLCO) at rest. Aim of investigators was to study whether abnormalities of lung diffusing capacity for nitric oxide (DLNO) and DLCO in long COVID may have a clinical impact in relation to exercise intolerance. Combined DLNO and DLCO were simultaneously measured at rest and immediately after a short bout of treadmill walking in 32 dyspneic subjects ≥3 months after the COVID-19 acute phase. A group of healthy subjects served as a control group.

• Study Type: Observational
• Enrollment (Actual): 32

Contacts and Locations

Study Locations

• Italy
  • Genoa, Italy, 16132
    • Ospedale Policlinico San Martino IRCCS - S.S. Fisiopatologia Respiratoria

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Caucasian subjects with a history of SARS CoV-2 infection confirmed by nasopharyngeal swab with real-time polymerase-chain reaction. They were referred to our pulmonary function laboratory after being tested negative for SARS-CoV-2, because of dyspnea, fatigue, and exercise intolerance persisting or occurring at least 3 months after the COVID-19 acute phase and lasting ≥2 months.

Description

Inclusion Criteria:

• History of dyspnea, fatigue, and exercise intolerance persisting or occurring at least 3 months after the COVID-19 acute phase and lasting ≥2 months.

Exclusion Criteria:

• History of diseases potentially causing dyspnea or affecting pulmonary gas transport, i.e., bronchial asthma, lung bullous disease, chronic obstructive pulmonary disease, pulmonary interstitial fibrosis or vasculitis, hematological diseases, systemic collagen diseases, congestive heart failure, liver or renal diseases, and morbid obesity.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Control
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Long COVID; Caucasian subjects with a history of SARS CoV-2 infection confirmed by nasopharyngeal swab with real-time polymerase-chain reaction were included in the study. They were referred to investigators' pulmonary function laboratory after being tested negative for SARS-CoV-2, because of dyspnea, fatigue, and exercise intolerance persisting or occurring at least 3 months after the COVID-19 acute phase and lasting ≥2 months.	Diagnostic test: Lung volumes, spirometry and standard single-breath DLCO were measured at rest while combined DLNO and DLCO were measured at rest and post-exercise; DLNO and DLCO were measured at rest and 5-10 s after a bout of treadmill exercise simulating usual walking
Healthy controls; Anthropometrically-matched healthy subjects, without history of COVID-19 and vaccinated against SARS-CoV-2 infection.	Diagnostic test: Lung volumes, spirometry and standard single-breath DLCO were measured at rest while combined DLNO and DLCO were measured at rest and post-exercise; DLNO and DLCO were measured at rest and 5-10 s after a bout of treadmill exercise simulating usual walking

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Combined DLNO and DLCO changes after mild exercise	pulmonary gas exchange abnormalities in dyspneic long COVID subjects	through study completion, an average of 6 months

Collaborators and Investigators

• Sponsor: IRCCS Azienda Ospedaliera Universitaria San Martino - IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy

Study record dates

Study Major Dates

• Study Start (Actual): May 24, 2022
• Primary Completion (Actual): June 15, 2022
• Study Completion (Actual): June 15, 2022

Study Registration Dates

• First Submitted: June 19, 2022
• First Submitted That Met QC Criteria: June 23, 2022
• First Posted (Actual): June 24, 2022

Study Record Updates

• Last Update Posted (Actual): June 24, 2022
• Last Update Submitted That Met QC Criteria: June 23, 2022
• Last Verified: June 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Signs and Symptoms, Respiratory; Lung Diseases; Dyspnea
• Other Study ID Numbers: Long_COVID_Exer_DLNO_DLCO

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

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