Kidney Week

Abstract: PO0489

Oxygen Kinetics and Microvascular Function in CKD

Session Information

• CKD Risk Factors: Diet, Environment, Lifestyle
  October 22, 2020 | Location: On-Demand
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Bohmke, Natalie J., Virginia Commonwealth University, Richmond, Virginia, United States

Natalie J. Bohmke,

• Ramick, Meghan G., West Chester University of Pennsylvania, West Chester, Pennsylvania, United States

Meghan G. Ramick,

• Edwards, David G., University of Delaware, Newark, Delaware, United States

David G. Edwards,

• Kirkman, Danielle L., Virginia Commonwealth University, Richmond, Virginia, United States

Danielle L. Kirkman,

Background

Patients with chronic kidney disease (CKD) have reduced cardiorespiratory fitness levels that are associated with reduced quality of life and mortality. Impaired oxygen uptake kinetics create a larger oxygen deficit that promotes fatigue. CKD related microvascular dysfunction may contribute to impaired oxygen uptake kinetics by hampering oxygen delivery to the working muscle. The purpose of this study is to investigate the relationship between oxygen kinetics and a measure of microvascular function in CKD.

Methods

13 patients with stage 3-5 CKD (Mean±SD, Age 60±14 years; eGFR 48.5±10.3 ml/min/1.73m²) were included in the analysis. Peak oxygen consumption (VO_2peak) was measured via breath by breath expired respiratory gas analysis during a symptom limited graded cycle ergometry test. Oxygen kinetics were quantified as mean response time (MRT), the exponential time constant to reach 63% of steady state VO₂. MRT was analyzed from three minutes of steady state submaximal cycling (<60% VO_2peak). Microvascular function was assessed as cutaneous vasodilation during local heating coupled with intradermal microdialysis, measured by laser Doppler flowmetry.

Results

VO_2peak was 20.36±6.87ml/kg/min. A moderate inverse correlation was shown between oxygen uptake kinetics and microvascular function (Figure 1; r=-0.56, p=0.02).

Conclusion

Microvascular dysfunction may contribute to a larger oxygen deficit in CKD patients. Following further studies, microvascular function could serve as a potential treatment target to improve exercise tolerance in these patients.

Funding

• Other NIH Support