Association Between Dyspnea Severity, Functional Exercise Capacity, and Carotid Intima-Media Thickness in Chronic Obstructive Pulmonary Disease

Background: Dyspnea and reduced exercise capacity are hallmark features of chronic obstructive pulmonary disease (COPD). Emerging evidence suggests that systemic vascular changes, particularly increased carotid intima-media thickness (CIMT), may contribute to functional limitation. Objective: To evaluate the association between dyspnea severity (mMRC), functional exercise capacity (6MWD), and CIMT in patients with COPD. Methods: We conducted a cross-sectional study on 31 stable COPD patients. Demographics, spirometry, GOLD staging, CIMT (measured by high-resolution B-mode ultrasonography), mMRC dyspnea grade, and six-minute walk distance (6MWD) were recorded. Correlations between CIMT, mMRC, and 6MWD were analyzed using Pearson’s correlation coefficient. Results: Patients with higher dyspnea scores (mMRC ≥3) demonstrated significantly higher CIMT (2.1 ± 0.6 mm) and lower 6MWD (320 ± 80 m) compared with those with mMRC ≤1 (CIMT 0.7 ± 0.2 mm, 6MWD 500 ± 60 m; p<0.01). CIMT positively correlated with mMRC (r = 0.61, p<0.01) and inversely with 6MWD (r = –0.58, p<0.01). Conclusion: Increased CIMT is strongly associated with higher dyspnea severity and reduced exercise capacity in COPD patients, suggesting systemic vascular remodeling as a contributor to functional limitation beyond airflow obstruction. Key words: COPD, dyspnea, CIMT, six-minute walk distance, systemic atherosclerosis