Changes in Microcirculation and Functional Status During Exacerbation of COPD

Study Overview
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Brief Summary
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This study investigates the influence of acute exacerbation of chronic obstructive pulmonary disease (COPD) on retinal microcirculation, on functional status and also investigates the prognostic value of retinal vessel caliber assessment in terms of hospitalization and mortality during 2 years of follow-up.

Detailed Description
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Recent findings suggest that patients with chronic obstructive pulmonary disease (COPD) are at increased risk for myocardial infarction and stroke during periods of acute exacerbation. These findings might be related to acute endothelial changes associated to increased systemic inflammation. Changes in the microcirculation can be explored noninvasively by studying retinal blood vessels that are visualized in fundus images. The retinal blood vessels have anatomical and physiological features that are comparable with the coronary circulation. Patients with COPD experience quadriceps muscle weakness, which worsens during hospitalization by  1% per day. This is the result of physical inactivity, in combination with increased oxidative stress and systemic inflammation. Physical inactivity is induced by the hospital environment, but is also related to symptoms of dyspnea caused by increased work of breathing and oxygen desaturation. Muscle weakness and physical inactivity are associated to poor functional status and recurrent hospital admissions, independent of pulmonary impairment, which makes those patients with frequent exacerbations prone to enter a vicious cycle. Simple functional screening tests during hospital stay might enable us to quantify the impact of a hospitalization on functional status and to identify patients at risk for repeated exacerbations.

Official Title
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Changes in Microcirculation and Functional Status During Exacerbation of COPD

Conditions
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COPD Exacerbation, Physical Activity, Retinal Vascular

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Stable COPD (post-bronchodilator forced expiratory volume / forced vital capacity < 0.7), no exacerbations in the previous weeks. COPD patients with diagnosis of acute exacerbation, based on the GOLD criteria. Exclusion Criteria: Inability to walk without support from others

Ages Eligible for Study
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Minimum Age: 40 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| COPD-stable<br>Stable COPD patients at pulmonology consultation in Ziekenhuis Oost-Limburg (ZOL) Genk | |
| COPD-Ex<br>Patients admitted to the respiratory ward of ZOL Genk with a diagnosis of acute exacerbation, based on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in Retinal microcirculation | Fundus of the right eye will be photographed using a retinal camera. The vessel diameters had geometric patterns will be measure. | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Changes in Functional status tests | Short physical performance battery (SPPB), which consists of a four meter gait test, a five-repetition sit-to-stand test and a balance test will be done. All the testes ranged from 0 to 4 and the sum of the three components comprised the final SPPB score, with a possible range from 0 to 12. | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional exercise tolerance | Six minute walk test will be done | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Muscle Function | Handgrip and Isometric-eccentric quadriceps strength test will be done | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Changes in Daily physical activity | Activity level will be assess by an accelerometer, the patient will be worn for 7 days. | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Impact of the disease | The COPD assessment test will be applied | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Impact of the dyspnea | The modified medical research council scale will be applied | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Impact of the depression | The patient health questionnaire will be applied | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Impact of the fatigue | The checklist individual strength- fatigue sub-scale will be applied | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Body composition | Bio-electrical impedance analysis will be used to estimate fat-free body mass based on the assessment of total body water. Body mass index and waist circumference will provide general information about body composition. | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Cardiovascular parameters | Resting ankle and brachial blood pressure will be measured and the ankle brachial pressure index will be calculated by the ratio of ankle to ipsilateral brachial systolic blood pressure | Stable: Outpatient clinic/ COPD exacerbated: Day 2-3 in hospital; Day 5-7 in hospital; 4 weeks after discharge | 
| Continuous assessment of oxygen saturation | A portable pulse oximeter will be worn to asses transcutaneous oxygen saturation for 24 hours in patients with an exacerbation. | COPD exacerbated: Day 5-7 in hospital; 4 weeks after discharge | 
| Continuous assessment of heart rate | A portable pulse oximeter will be worn to asses heart rate for 24 hours in patients with an exacerbation. | COPD exacerbated: Day 5-7 in hospital; 4 weeks after discharge |