Avaliação da função respiratória, da capacidade física e da qualidade de vida de pacientes com doença renal crônica pré-dialítica

Abstract

Introduction: Chronic Kidney Disease (CKD) evolves with progressive and irreversible loss of kidney function. Its clinical manifestations and complications cause reduction in physical capacity, low exercise tolerance, reduced quality of life (QOL) self-reported and therefore difficult to perform activities of daily living. Their clinical and metabolic disturbances characteristic of uremia, are already present in patients from the pre-dialysis stage. However, the literature is unclear as to the existence and the factors associated with changes in lung function in patients with pre-dialysis CKD. Objectives: To evaluate the respiratory function, physical capacity and self-reported quality of life in patients with pre-dialysis CKD stages three, four and five of the disease and compare them with healthy volunteers. Methods: We conducted a cross-sectional study that evaluated 38 adult volunteers divided into two groups: a control group (CG) with nine healthy subjects and a group with 29 patients with pre-dialysis CKD stages three, four and five (G3, G4 and G5, respectively) belonging to the Department of Nephrology, University Hospital, Federal University of Juiz de Fora (HU-UFJF), from the Program for the Prevention of Kidney Diseases, the Center for Interdisciplinary Studies, Research and Treatment in Nephrology, Federal University of Juiz de Fora and IMEPEN Foundation (PREVENRIM - NIEPEN / UFJF). Inclusion criteria: adult patients, belonging to stages three, four and five CKD, who agreed to participate by signing an informed consent. The exclusion criteria were patients with age over 65 years, previously diagnosed pulmonary disease, smokers, former smokers who smoked above 20 pack / years and / or who stopped smoking less than ten years, cognitive and musculoskeletal that compromised the testing, unstable angina, active infection in the last three months, uncontrolled hypertension (systolic blood pressure ≥ 200 mmHg and / or diastolic blood pressure ≥ 120 mmHg), using drugs that affect the function of the respiratory muscles, as cyclosporine and steroids or not agreed to participate. To form the control group, we selected healthy individuals matched for age, sex and body mass index (BMI), respecting the same criteria for inclusion. All volunteers were evaluated according to the following protocol: First Visit-Medical Evaluation and Physical Therapy; collection of two blood samples, one for analysis of laboratory data and one for storage of serum; completion of Six-Minutes Walk Test; Manovacuometry; and implementation of the Quality of Life Questionnaire Short Form-36 self-reported. Second Visit: spirometric evaluation. Third Visit: Cardiopulmonary Exercise Test. In addition, records were removed from the data on nutritional assessment. Statistical analysis Data were expressed as mean and standard deviation or percentage as the characteristic variable. For comparison between stages, we used ANOVA, Kruskal-Wallis test or chi-square test. To evaluate the association between variables, we used the Pearson correlation or Spearman, as the characteristic variable. Considered significant at p <0.05. Used the statistical software SPSS 13.0 Results: Compared with control subjects, there was no difference between patients with CKD with respect to age, sex and BMI. The most common cause of CKD were hypertensive nephrosclerosis (34.4%), followed by chronic glomerulonephritis (20.6%) and diabetic kidney disease (17.2%). The most prevalent comorbidities were hypertension (96.5%), dyslipidemia (68.9%) and diabetes mellitus (24.1%). There were significant differences in laboratory variables and iPTH (CG = 71.2 ± 29.8 pg / mL, G3 = 77.0 ± 24.9 pg / mL, G4 = 114.2 ± 52.2 pg / mL, G5 = 337, 2 ± 283.0 pg / mL, p = 0.004) and hemoglobin (CG = 15.0 ± 1.8 g / dL, G3 = 13.7 ± 1.4 g / dL, G4 = 12.3 ± 1.3 g / dL, G5 = 12.3 ± 1.6 g / dL, p = 0.003). Pulmonary Function showed no statistically significant difference between groups in spirometric parameters, but in the manometer, maximal inspiratory pressure (MIP) showed statistically significant difference in absolute values (GC = 95.0 ± 17.6 cmH2O, G3 = 61.0 ± 26.8 cmH2O, G4 = 60.5 ± 14.6 cmH2O, G5 = 66.1 ± 25.3 cmH2O, p = 0.024). Moreover, most of the variables related to physical capacity measured by cardiopulmonary exercise testing, as the relative power output (GC = 4.9 ± 1.3 W / kg, G3 = 3.7 ± 0.9 W / kg, G4 = 3.0 ± 1.2 W / kg, G5 = 3.2 ± 1.0 W / kg, p = 0.007), and oxygen consumption (VO2peak) (GC = 85.4 ± 18.2%, G3 = 75 , 18.3 ± 8%, G4 = 65.9 ± 16.0%, G5 = 63.4 ± 16.0%, p = 0.038) and functional capacity measured by distance walked in the Six Minutes Walk Test (6MWT) (GC = 90.5 ± 7.6%, G3 = 93.9 ± 7.5%, G4 = 83.4 ± 9.5%, G5 = 83.0 ± 8.9%, p = 0.017) showed statistically significant differences. In addition, glomerular filtration rate (GFR) was associated with laboratory variables (hemoglobin, r = 0.596 and p = <0.0001), pulmonary function (FEV1 (%) r = 0.349 and p = 0.020; PImax (cmH2O) (r = 0.415 and p = 0.015) and physical capacity (peak VO2 (ml / kg.mim) r = 0.430 and p = 0.008) and functional (6MWT (m) r = 0.556 and p = <0.0001). Evaluating the quality of life (QOL) by SF-36, we observed a decline of the same in functional capacity (p = 0.003), physical (p = 0.012), general health (p = 0.008), social functioning (p = 0.002), with the progression of CKD stage. QOL was associated with variables related to pulmonary function and cardiopulmonary exercise testing. It is noteworthy that there was a significant correlation between the physical functioning domain assessed by the SF-36 and the walking distance in the 6MWT (r = 0.766 and p <0.0001) and VO2peak in absolute values in CPET (r = 0.688 and p <0.0001). Conclusion: Patients with CKD pre-dialysis had abnormal lung function and physical capacity and functional parameters and their association with GFR suggests that the progression of the disease aggravates these functions. Moreover, there was a worsening of QOL associated with worsening GFR and the association between QOL and functional capacity evaluated by the 6-minute walk and exercise capacity assessed by CPET, indicating that the assessment performed by subjective QOL questionnaire reflects the objective evaluation assessment the 6MWT and the CPET and we can suggest this as a screening instrument for assessing functional / physical in patients with pre-dialysis CKD.