Correlation between anemia-related red blood cell parameters and pulmonary function severity in patients with AECOPD

Aim This study aimed to investigate the prevalence of anemia and the correlation between specific red blood cell (RBC) parameters—particularly red cell distribution width (RDW) and mean corpuscular hemoglobin (MCH)—and pulmonary function severity in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods A retrospective, single-center cohort study was conducted involving 120 hospitalized AECOPD patients. Participants were stratified by lung function grade (GOLD 1–4) and anemia status. Data on demographics, RBC parameters (Hb, RDW, MCH, MCV), and clinical outcomes were collected. Statistical analyses included correlation tests, ROC curve analysis, multivariate logistic regression, and Kaplan-Meier survival analysis. Results The overall anemia prevalence was 26.7%, increasing significantly with lung function severity, exceeding 50% in GOLD grade IV. RDW exhibited a significant negative correlation with FEV1%pred ( r = –0.418, P 0.001), while MCH showed a positive correlation ( r = 0.391, P 0.001). Multivariate analysis identified decreased Hb and elevated RDW as independent factors associated with severe lung impairment (Grades III–IV). The anemia group had significantly longer hospital stays, and patients with high RDW levels demonstrated significantly reduced survival. Conclusion Anemia is highly prevalent in AECOPD and is closely but moderately associated with disease severity. RDW and MCH are indicators that show independent associations with lung function impairment and selected clinical outcomes in this cohort, but these relationships cannot be interpreted as causal because of the observational study design. Integrating these readily available RBC parameters into routine assessment could help enhance risk stratification when interpreted alongside established clinical and physiological markers.