Kidney Week

Abstract: SA-PO431

Altered Lactate Metabolism at Peak Exercise in Patients on Dialysis

Session Information

• Hemodialysis and Frequent Dialysis - 2
  October 26, 2024 | Location: Exhibit Hall, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 801 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Groninger, Nolan, Indiana University School of Medicine, Indianapolis, Indiana, United States

Nolan Groninger

• Arroyo, Eliott, Wake Forest University, Winston-Salem, North Carolina, United States

Eliott Arroyo, PhD

• Burney, Heather, Indiana University School of Medicine, Indianapolis, Indiana, United States

Heather Burney, MS

• Narayanan, Gayatri, Indiana University School of Medicine, Indianapolis, Indiana, United States

Gayatri Narayanan, MS

• Karp, Sharon L., Indiana University School of Medicine, Indianapolis, Indiana, United States

Sharon L. Karp, MD, MPH

• Lim, Kenneth, Indiana University School of Medicine, Indianapolis, Indiana, United States

Kenneth Lim, MD, PhD, FASN

Background

Patients with end-stage kidney disease (ESKD) on hemodialysis commonly exhibit exercise intolerance, as reflected by decrements in oxygen uptake at peak exercise (VO₂Peak). Cardiopulmonary exercise testing (CPET) is the gold-standard for obtaining VO₂Peak and requires participants to exercise past their anaerobic threshold, leading to increased blood lactate concentrations. The purpose of this study was to compare lactate response to maximal exercise in patients with ESKD versus healthy controls.

Methods

We analyzed data from the ongoing “Comparison of the Self-Paced versus Ramp Incremental Exercise Protocols on Patients with Kidney Failure (SPARK)” trial. Participants completed CPET and capillary blood samples were taken at rest, warm-up, and every 2 minutes of exercise and analyzed for blood lactate levels. Wilcoxon tests were conducted to compare blood lactate values between patients with ESKD and healthy controls. Adjusted analysis was conducted using multiple linear regression modeling.

Results

A cohort of 10 patients with ESKD (n=4 men, mean [SD] age=49 [11] years, dialysis vintage=27 [IQR: 14-45] months) and 21 healthy controls (n=10 men, age=55 [9] years) were included in this analysis. Hemoglobin was significantly lower in ESKD patients (11.5 [1.7] g/dl) compared to healthy controls (14.3 [1.0] g/dl; P<0.001). There were no differences in age (P=0.10) or sex (P=0.99) between groups. Resting lactate levels were significantly greater in ESKD patients (1.3 [0.4] mmol/L) than in healthy controls (0.9 [0.3] mmol/L; P=0.029). Significantly, lactate levels at peak exercise were lower in ESKD patients (3.4 [2.7-4.3] mmol/L) compared with healthy controls (7.8 [7.0-9.2] mmol/L; P<0.001), even after adjusting for hemoglobin (P<0.001).

Conclusion

ESKD is complicated by lactatemia in the resting state and may in part, be a direct consequence of impaired renal clearance. The lower levels of lactate at peak exercise in patients with ESKD are reflective of impaired exercise intolerance in the anaerobic phase and indicate a reduced capacity to sustain exercise above the lactate threshold.