Long COVID and Post-exertional Pulmonary Diffusion

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

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT05430503

Acronym

Long_COVID_Ex

Enrollment

Registered

2022-06-24

Start date

2022-05-24

Completion date

2022-06-15

Last updated

2022-06-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Alveolar Lung Disease, Breathlessness, Exercise Intolerance, Long COVID, Pulmonary Gas Exchange

Brief summary

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.

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.

Interventions

DIAGNOSTIC_TESTLung 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

Study design

Observational model

CASE_CONTROL

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Healthy volunteers

Yes

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.

Design outcomes

Primary

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

Countries

Italy

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026