CHRONIC KIDNEY DISEASE IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE: A ROLE OF EXACERBATIONS

Abstract

The aim of the study was to investigate a relationship between frequency of exacerbations of chronic obstructive pulmonary disease (COPD) and renal dysfunction in patients with COPD. Methods. We examined 200 patients with COPD diagnosed according to GOLD, 2015. The patients were divided into 4 groups according to a rate of exacerbations of COPD and severity of symptoms. A and B groups had rare exacerbations (≤ 1 per year), C and D groups had frequent exacerbations (≥ 2 per year). Patients in A and D groups experienced less symptoms of COPD and patients in B and C groups had more symptoms. To investigate the renal function, glomerular filtration rate (GFR) was calculated in all patients twice during 6 months using the СKDEPI formula; also, albuminuria (AU) was measured and renal ultrasonography was performed. Results. Pathological kidney disorders were found in 106 patients (53%). Positive correlations were found between the renal resistance index (RI) and FEV1 and between RI and age of the patients. Inverse correlations were found between FEV1 and increased AU and between frequency of exacerbations and AU. Chronic kidney disease (CKD) was diagnosed in 105 patients with COPD (52.5%). A persistent decrease in GFR < 60 ml/min/1.73m2 was revealed in 74 patients with COPD (37.0%). Stage I – II CKD was diagnosed in 31 of 126 COPD patients with normal or slightly decreased GFR (15.5%). Thus, stage I CKD was diagnosed in 13 patients with COPD (6.5%), stage II CKD was diagnosed in 18 patients (9.0%), stage III A CKD was diagnosed in 54 patients (27.0%), stage III B CKD was diagnosed in 16 patients (8.0%), and stage IV CKD was diagnosed in 4 patients (2.0%). Conclusions. CKD was diagnosed in 52.5% of patients with COPD. The prevalence of CKD was significantly higher in C and D groups. Stage III – IV CKD was diagnosed in patients with frequent exacerbations of COPD significantly more often. Clinically significant AU could be related to higher cardiovascular risk. Renal dysfunction in COPD patients could be due to endothelial dysfunction and systemic effects of COPD.