Peripheral Arterial Disease as an Underdiagnosed Entity in COPD and its Impact on Functional Exercise Capacity- A Cross-sectional Study from a Tertiary Care Hospital in Eastern India

Abstract

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a significant cause of morbidity and mortality globally. COPD is a systemic disease, cardiovascular and Peripheral Arterial Disease (PAD) are common entities in COPD. Asymptomatic, undiagnosed PAD can lead to impaired functional exercise capacity, increased morbidity and mortality. Aim: To find out the occurrence of PAD in COPD and relative contribution of PAD, severity of COPD, and Health Related Quality of Life (HRQL) on functional exercise capacity. Materials and Methods: The present study was a prospective, cross-sectional, analytical study carried out in the Department of Respiratory Medicine of a teaching institution in eastern India over a period of six months. All COPD patients diagnosed as per Global Initiative for Obstructive Lung Diseases (GOLD) criteria were recruited for the study after obtaining written informed consent. HRQL was assessed by Clinical COPD Questionnaire (CCQ). Exercise capacity was assessed by Six Minute Walk Test (6MWT) and PAD was evaluated by Ankle Brachial Index (ABI) on Ultrasound (USG) Doppler. Data were analysed using appropriate statistical tests. Mean, Standard Deviation (SD) and percentages were calculated for descriptive frequencies, p-value was calculated using Fischer’s-exact test or Chi-square test for categorical data and independent sample t-test and Kruskal Wallis test for parametric and non parametric data, respectively. Results: Out of 75 COPD patients, PAD was present in 18 (24%) patients. Majority of COPD patients (n=35; 46.6%) were in GOLD group D. There was no statistically significant difference in age, Body Mass Index (BMI) and smoking index between COPD with and without PAD. Most PAD patients were asymptomatic. In comparison to COPD without PAD, severe PAD cases had significantly less Six Minute Walk Distance (6MWD), more episodes of leg cramps and needed to stop more frequently during 6MWT. Apart from PAD, increasing severity in COPD was associated statistically significant changes in Forced Expiratory Volume in the first second (FEV1), CCQ score, 6MWD, post 6MWT Heart Rate (HR), Respiratory Rate (RR), Borg score, fatigue, Oxygen Saturation (SpO2). Conclusion: The PAD is a frequent entity in COPD and can be diagnosed easily by measuring ABI. Increasing COPD severity affect HRQL and exercise capacity significantly.