MP468PULSE PRESSURE INCREASES AFTER 6-MIN WALK TEST WITH ADVANCEMENT OF CKD

Abstract

INTRODUCTION AND AIMS: The 6-min walk-test (6MWT) is currently recommended in EBPG 2016 as to be performed every 6-8 weeks in with GFR <45ml/min/ 1.73m2, especially in elderly. Numerous demographic, physiological and anthropometric factors can influence the 6MWT in healthy adults but hemodynamic parameters measured during 6MWT may result from advanced stage of chronic kidney disease (CKD). The aim of the study was to compare hemodynamic parameters (blood pressure, pulse pressure, HR) pre- and post-submaximal exercise (6MWT) in three groups of CKD patients G1-2, G3-4 and G5 according to KDIGO2012 classification. METHODS: Sixty seven CKD patients (25 pts in G1-2, 20 pts in G3-4 and 22pts in G5; all age, gender and BMI adjusted) participated in the study ( table 1). To verify variability of hemodynamic parameters and distance walked the test was repeated within next 2-5 days. Dialyzed pts (G5) did the test on non dialysis days. Both tests were performed in the same conditions (hospital corridor with definite 20m distance, the same temperature, morning hours, the same footwear). In addition to anthropometric data (sex, age, height, weight), the following data were recorded pre- and post-exercise oxygen saturation, heart-rate, systolic/ diastolic blood pressure, dyspnoea Borg value, hemoglobin and albumin level. All patients did not participated in last 6 months in supervised physical therapy program and met following exclusion criteria: active infection or cancer, cardiovascular event in last 3 months, NYHA >II, difficulty walking or vision problems. RESULTS: Majority hemodynamic measures in the second test repeated after 2-5 days did not differ significantly with the previous ones (p>0.5 in Wilcoxon test) except for sys blood pressure in CKD G1-2 (136 vs 132 mmHg, p=0,04). Expected physiological changes resulting from CKD progression were noticed in parameters taken in rest (pre test) and were most prominent between CKD G1-2 and G5 for pulse pressure and sys blood pressure, G1-2 and G3-4 for heart rate and pulse pressure (table 1). Hemodynamic responses to a submaximal stress (6MWT) differed among CKD G1-5 patients mostly in pulse pressure and sys blood pressure (table1). Dialyzed pts ( CKD G5) showed highest pulse pressure after the test revealing poorer vascular reactivity. It also increased during the test (56 vs 63 mmHg, p=0,02 in Wilcoxon test). CONCLUSIONS: In CKD patients beside distance walked also pulse pressure after 6MWT should be noticed as easy to measure indicator of vascular auto-regulation. This parameter (related to arterial stiffness) should be monitored during and after physical therapy program. (Table Presented).