CKD patients have augmented beat-to-beat BP variability that is not improved with 12 weeks of cycling exercise

Abstract

Increased blood pressure (BP) variability is a powerful predictor of cardiovascular events and end-organ damage and is associated with sympathetic overactivity. Given the heightened cardiovascular (CV) risk in patients with chronic kidney disease (CKD), we hypothesized that patients with CKD would exhibit augmented resting beat-to-beat BP variability. Additionally, since aerobic exercise training exerts CV protective effects and has been shown to reduce resting sympathetic activity, we hypothesized that twelve weeks of aerobic exercise training would improve resting beat-to-beat BP variability in patients with CKD. In 25 sedentary patients with CKD stages III-IV [19 male/6 female, age: 62 ± 10 yr, 23 Black/2 White, systolic/diastolic BP: 130 ± 12/73 ± 9 mmHg, BMI: 31 ±7 kg/m 2 ] and 15 controls [11 male/4 female, age: 56 ± 11 yr, 13 Black/2 White, systolic/diastolic BP: 129 ± 12/83 ± 8 mmHg, BMI: 29 ± 3 kg/m 2 ], resting beat-to-beat blood pressure (finger photoplethysmography) was continuously measured for 5–10 min. Next, a subset of patients with CKD (n = 13) underwent 12 weeks of aerobic cycling exercise (spinning at 85% of maximal heart rate reserve). Exercise training was performed 45 minutes/session 3 days/week. All measurements were performed at baseline (n=40) and following the 12-week intervention (n=13). We calculated the standard deviation (SD), the coefficient of variation [CV (SD/mean)×100], and the average real variability (AVR) as indices of BP variability. Compared with controls, patients with CKD had significantly increased BP variability. The systolic SD BP (6.0 ± 2.1 vs. 3.9 ± 1.8 mmHg, P = 0.002) and the mean SD BP (3.9 ± 1 vs. 2.8 ± 1 mmHg, P = 0.006) were increased in CKD vs. Controls, but there were no differences in diastolic SD BP between groups (3.3 ± 1 vs. 2.6 ± 1 mmHg, P = 0.065). Similar results were found using AVR (Systolic AVR 2.0 ± 0.5 vs. 1.1 ± 0.5 mmHg, P > 0.001 and, Mean AVR, 1.3 ± 0.5 vs. 1.0 ± 0.3 mmHg, P = 0.010 for patients with CKD and controls respectively). Contrary to our hypothesis, we observed no significant change in resting beat-to-beat BP variability after 12 weeks of exercise in patients with CKD (SD SBP 6.3 ± 2.1 vs. 5.7 ± 2.0 mmHg, P = 0.893 and, AVR 1.9 ± 0.5 vs. 1.9 ± 0.6 mmHg, P = 0.970). In summary, our data demonstrate that patients with CKD have augmented beat-to-beat BP variability, and 12 weeks of cycling exercise did not reduce resting beat-to-beat BP variability in CKD patients. This work was supported by National Institutes of Health Grants R01HL135183 and R61AT010457 (J.P). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.