P742 The role of oxidative stress and inflammation for stress induced right ventricular diastolic dysfunction in non-severe chronic obstructive pulmonary disease patients

Abstract

Background Oxidative stress and inflammation have been implicated in the pathogenesis of diastolic dysfunction (DD) and are both present in chronic obstructive pulmonary disease (COPD). Aim To evaluate the role of oxidative stress markers (8-isoprostane) and inflammation (prostaglandin E2, resistin) in the pathogenesis of stress induced right ventricular diastolic dysfunction (RVDD) in non-severe COPD. Materials and methods 104 patients with non-severe COPD (FEV1 > 50%) and preserved left ventricular ejection fraction >50% underwent incremental cardio-pulmonary exercise testing (CPET). Echocardiography was performed before CPET and 1-2 minutes after peak exercise. Peak E/e’ ratio > 6 was a marker for stress induced RVDD. Urine concentration of 8-isoprostanes was assumed as surrogate marker for oxidative stress; urine concentration of prostaglandine-E2 and plasma resistin levels as inflammatory markers. Mass spectrometry was applied for 8-isoprostane and prostglandine E2 (Cayman. Chemical) measurement. Values were normalised to urine creatinine (µmol/l/cre). ELISA was applied for resistin measurement (Raybio_Human) (ng/ml). Results Patients were divided into two groups: subjects with stress RVDD (82) and those without stress RVDD (22). In patients with and without RVDD the levels of 8-isoprostane were similar (30.78 vs 30.41µmol/l/cre). The urine concentration of prostaglandin E2 in patients with and without RVDD significantly differed (49.73 vs 62. 19µmol/l/cre; p < 0.05). The same is observed regarding resistin plasma levels - in patients with and without RVDD (18.91 vs 5.47ng/ml). Conclusions In non-severe COPD patients oxidative stress levels are similar in the studied groups. Inflammation (resistin) seems to be the predominant pathogenetic factor, associated with stress induced RVDD. The exact role of prostaglandine E2 for RVDD remains elusive.