Avaliação da taxa de filtração glomerular e albuminúria em pacientes portadores de doença pulmonar obstrutiva crônica

Abstract

The consonance between chronic kidney disease (CKD) and Chronic Obstructive Pulmonary Disease (COPD), two age-related conditions, has fundamental clinics and prognoses. The effect of age on kidney and lung function increases the complexity of the interplay between the kidney and the lung. The aim of this study is to investigate the prevalence of chronic kidney disease in patients with COPD using the creatinine-based glomerular filtration rate (GFR), in addition to trying to correlate GFR, albuminuria and FEV1 (forced expiratory volume in the 1st second) with the COPD groups, since there are several gaps about the lung-kidney interaction, which requires further research for such an analysis. A cross-sectional observational study was carried out with patients previously diagnosed with Chronic Obstructive Pulmonary Disease at the Professor Alberto Antunes University Hospital (HUPAA) in Maceió-AL, northeastern Brazil, from September 2020 to March 2021. A disease-specific symptom questionnaire was performed, besides the analysis of the last spirometry. After data collection, these patients were categorized and divided according to the GOLD 2019 classification groups (A, B and C/D). Serum creatinine, creatinine and albumin were measured in an isolated urine sample to estimate the glomerular filtration rate using the formula CKD - EPI and to define the presence of albuminuria (> 30mg/g albumin/creatinine). Forty-five patients were analyzed (male sex 64.4%, mean age 69.11 ± 9.79, DM 15.5% and hypertension 57.7%). CKD was diagnosed in 22 (48.9%) patients. Of these, 9 (40,9%) patients had only a reduction in GFR, 19 (86,3%) had an increase only in albuminuria, while 6 (27.2%) had altered albuminuria and GFR. Among the patients, 24 were classified as GOLD A, 9 as GOLD B and 12 as GOLD C/D. The mean GFR in GOLD A, B and C/D was, respectively, 75.3 ± 13.74 ml/min/1.73 m2, 74.2 ± 17.27 ml/min/1.73 m2 and 75.7 ± 16.42 ml/min/1.73 m2 (p>0.05). The median of albuminuria in GOLD A, B and C/D was, respectively, 12.27 mg/g (7.21-31.90), 47.83 mg/g (23.45-181.26) and 25.80 mg/g (18.23-64.30) (p>0.05). There was a high prevalence of patients with CKD in the study. GFR was not different between groups and, despite the higher albuminuria in group B and C/D, the difference was not statistically significant.