Value of the neutrophil-to-lymphocyte ratio in chronic obstructive pulmonary disease complicated with pulmonary hypertension

OBJECTIVE: To investigate the relationship between the neutrophil-to-lymphocyte ratio and chronic obstructive pulmonary disease complicated with pulmonary hypertension (COPD + PH). METHODS: We retrospectively analyzed clinical data from 242 COPD patients at our hospital from July 2018 to July 2019. Patients underwent examinations including blood analysis, C-reactive protein, N-terminal brain natriuretic peptide (BNP), pulmonary function, and cardiac color ultrasound. RESULTS: Patients were divided into the COPD and COPD + PH groups using pulmonary arterial pressure (<50 and ≥50 mmHg, respectively). Compared with the COPD group, the COPD + PH group had greater pulmonary arterial pressure, smoking history, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein, BNP, Chronic Obstructive Pulmonary Disease Assessment Test score, and right atrium and ventricular diameters, but smaller body mass index, forced vital capacity, lymphocyte count, and left ventricular diameter. BNP and NLR had positive effects on PH; forced vital capacity had a negative impact. Moreover, BNP (area under the curve [AUC] = 0.748, sensitivity = 0.692, specificity = 0.701) and NLR (AUC = 0.679, sensitivity = 0.831, specificity = 0.452) had predictive value for PH, and both were positively correlated with PH. CONCLUSIONS: NLR is associated with COPD + PH, and may be useful for its diagnosis.