Aerobic Exercise Training Attenuates Blood Pressure Response During Maximal Aerobic Exercise and Improves Endothelial Function in Chronic Kidney Disease

Abstract

IntroductionChronic Kidney Disease (CKD) patients experience an exaggerated increase in blood pressure during exercise that is associated with an increased risk of cardiovascular mortality. Recent work from our group suggests that this exaggerated blood pressure response is associated with endothelial dysfunction. We hypothesized that 12 weeks of structured, aerobic exercise training would attenuate blood pressure increases during maximal exercise and improve endothelial function compared to stretching (an active control intervention) in CKD.Methods12 participants (age =65±2y) with CKD stages III or IV were randomized to 12 weeks of supervised aerobic cycling exercise (N=6) or stretching (N=6) for 45 minutes, 3 times per week. A maximum treadmill exercise test was performed via the modified Balke Protocol to assess blood pressure response and maximal aerobic capacity (VO2peak) before and after the 12‐week intervention. Blood pressure was measured manually by a single investigator (J Park) during the final 30s of each stage of the maximal exercise test. Reactive hyperemia index (RHI), an index of endothelial function assessed via peripheral artery tonometry was also measured at the beginning and end of the intervention. A linear mixed model was used to compare the rate of increase in heart rate, systolic and diastolic blood pressure during the maximal exercise tests, and VO2peak and RHI were compared via a 2‐way repeated measures ANOVA.ResultsVO2peak increased in the exercise group (Pre, 24.6±2.5 vs. Post, 28.2±2.3 ml/kg/min, P=0.046) but not in the stretching group (Pre, 26.8±2.2 vs. Post, 26.04±2.1 ml/kg/min, P=0.641). Similarly, RHI tended to increase with exercise training (Pre, 1.68 ±0.1 vs. Post, 2.21±0.31, P=0.081) but not stretching (Pre, 1.59±0.06 vs. Post, 1.83±0.24, P=0.403). While there was a trend for an attenuation in the rate of increase in systolic blood pressure from pre‐ to post‐intervention in the exercise group (Pre, 11.3±1.1 vs. Post, 8.1±1.0 mmHg/stage, P=0.07), this difference was not observed in the stretching group (Pre, 12.8±1.7 vs Post, 13.0±1.3 mmHg/stage, P=0.876). There were no differences in heart rate or diastolic blood pressure responses during exercise in either group.DiscussionIn support of our hypothesis, 12 weeks of structured aerobic exercise training attenuates blood pressure responses during maximal exercise and improves endothelial function in CKD. These findings suggest that exercise training may attenuate the exaggerated blood pressure responses during exercise and improve endothelial dysfunction that characterize this population. Future work should seek to explore the mechanistic link between endothelial function and blood pressure responses in CKD and determine the optimum dose (frequency, intensity, and duration) of exercise training.Support or Funding InformationThis work was supported by National Institutes of Health R01 HL135183 (to J. Park); National Institutes of Health training grants T32 DK‐00756 (to J. Sands).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.