Incidence of pulmonary hypertension in COPD and its relation to inflammatory marker interleukin-1

Many COPD patients present with severe PH defined by a pulmonary vascular resistance (PVR) > 5 WU as measured by right heart catheterization (RHC), and inflammation is thought to be contributing strongly to pulmonary vascular remodeling in COPD besides hypoxia. Interleukin-1 (IL-1) is thought to be a major cytokine that may be involved in development of PH in these patients. This study aimed to identify the incidence of PH in COPD and its relation to inflammatory marker IL-1. One-hundred COPD patients underwent echocardiography and serum IL-1 analysis, and patients with high probability of PH underwent pulmonary artery catheterization using Swan-Ganz catheter. The mean serum IL-1 level was 82 pg/ml ± 22 pg/ml (the normal IL-1 serum level is known to be 0:5 pg/mL), 51% of the participants were categorized as having a low probability of PH, 35% was intermediate, and 14% was high. RHC results were as follows: mild combined pre- and postcapillary PH was diagnosed in 14.3% of the patients. Mild precapillary PH was found in 42.9%, making it the most common type. Severe combined pre- and postcapillary PH was noted in 21.4% of the patients. Severe precapillary PH was present in 14.3%. A significant positive correlations were observed between serum IL-1 and tricuspid regurgitation velocity (TRV) (r = 0.409, P < 0.001), estimated systolic pulmonary artery pressure (ESPAP) (r = 0.508, P < 0.001), and mean pulmonary artery pressure (mPAP) (r = 0.410, P = 0.140). Serum IL-1 is a potent predictor of a high probability of PH in COPD patients, and there was significant positive correlation between serum IL-1 and echocardiographic findings and PH probability and RHC findings in COPD patients.