Mechanisms of Exercise Intolerance in Chronic Obstructive Pulmonary Disease

Not Applicable

Completed

• Conditions: COPD
• Interventions: Other: Exercise

• Registration Number: NCT02360865
• Lead Sponsor: Rigshospitalet, Denmark

Brief Summary

1: Is endothelium function impaired in COPD? Other chronic cardiovascular diseases are associated with endothelial dysfunction, and the endothelium plays an important role in regulating vascular tone, tissue blood flow, coagulation and the inflammation process. Although the specific causes of endothelial dysfunction remain unclear, physical inactivity, chronic systemic inflammation and smoking are all known to be associated with endothelial abnormality.

2. Is Muscular Sympathetic Nerve Activity (MSNA) increased in COPD? A balanced regulation of blood flow to skeletal muscles may be disturbed by pathophysiology and may therefore contribute to the exercise intolerance and skeletal muscle depletion seen in patients with COPD.Skeletal muscle blood flow is tightly regulated to match tissue oxygen demands and is thus adapted to meet energy requirements. During physical activity, the sympathetic nervous system is activated ("exercise pressor reflex"), resulting in increased ventilation, heart rate and a redistribution of cardiac output from inactive to active tissues. The redistribution of cardiac output to the body organs is heterogeneous. Blood flow to skeletal, respiratory and cardiac muscle increases as exercise intensity increases, whereas blood flow to gastrointestinal, renal and reproductive tissues decreases. As blood pressure during exercise remains largely unchanged, the redistribution of blood flow is caused by changes in vascular conductance. These conductance changes are caused by an overall vasoconstriction induced by the increased sympathetic outflow of noradrenaline (NA), and a vasodilation of vascular beds supplying the working skeletal -, cardiac- and respiratory muscle.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2015-01-19
• Study Start: 2015-02
• Study First Submitted QC: 2015-02-05
• Study First Posted: 2015-02-11
• Primary Completion: 2016-05
• Study Completion: 2016-05
• Status Verified: 2016-06
• Last Update Submitted: 2016-06-15
• Last Update Posted: 2016-06-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 18

Inclusion Criteria

• Forced Expiratory Volume at on second/ Forced Vital Capacity fixed ratio <0.70, - Forced Expiratory Volume at one second <60% of predicted and Medical
• Research Council scale > or equal to 3
• Arterial oxygen saturation at rest> 90%,
• Body Mass Index >18,
• Left Ventricle Ejection Fraction> 45.

Exclusion Criteria

• Unstable ischemic heart disease,
• severe heart valve failure,
• pulmonary emboli,
• severe heart failure,
• severe infections,
• musculoskeletal disorders,
• malignant disease,
• contraindicated medicine as anticoagulants.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
COPD	Exercise	Acute exercise bouts
Healthy	Exercise	Acute exercise bouts

Primary Outcome Measures

Name	Time	Method
Muscular Sympathetic Nerve Activity During acute exercise (handgrip and leg isometric leg extension) by Peroneal microneurography	On one experimental day during acute exercise (handgrib and leg isometric leg extension) and change from baseline
Endothelium function during acute exercise (one legged kicking) by Flow doppler	On one experimental day during acute exercise (one legged knicking) and change from baseline	Flow doppler

Trial Locations

Locations (1)

Centre of Physical Activity Research; 🇩🇰 Copenhagen, Capital Region, Denmark