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Kidney Week

Abstract: PO2534

Middle Cerebral Artery Hemodynamics Is Blunted in Kidney Transplant Recipients

Session Information

Category: Transplantation

  • 1902 Transplantation: Clinical

Authors

  • Jurgensen, Andrew J., University of Kansas Medical Center Division of Nephrology, Kansas City, Kansas, United States
  • Ward, Jaimie, University of Kansas Medical Center Department of Physical Therapy and Rehabilitation, Kansas City, Kansas, United States
  • Morton, Allegra, University of Kansas Medical Center Department of Physical Therapy and Rehabilitation, Kansas City, Kansas, United States
  • Geise, Andrew P., University of Kansas Medical Center Department of Physical Therapy and Rehabilitation, Kansas City, Kansas, United States
  • Billinger, Sandra, University of Kansas Medical Center Department of Physical Therapy and Rehabilitation, Kansas City, Kansas, United States
  • Gupta, Aditi, University of Kansas Medical Center Division of Nephrology, Kansas City, Kansas, United States
Background

Kidney transplant (KT) recipients have a higher risk of dementia and cerebrovascular events than the general population. Cerebrovascular hemodynamic response (CVR) to constant-load moderate-intensity exercise marks the ability of the brain to respond to increased oxygen requirements with exercise. Blunted CVR seen with vascular disease and aging can increase risk of dementia and stroke. We evaluated the middle cerebral artery blood velocity (MCAv) dynamic response in KT recipients and compared it to age matched non-CKD controls.

Methods

35 KT recipients and 35 healthy controls completed a 90-second rest followed by a 6-minute moderate intensity exercise on a recumbent stepper at a prescribed step rate and workload. We used transcranial doppler (TCD) monitoring for MCAv while continuously monitoring heart rate and beat-to-beat mean blood pressure during rest and exercise. Baseline resting MCAv and steady state response during exercise was recorded. Outcome measures included resting MCAv and CVR (MCAv during steady state exercise – baseline MCAv) and workload needed to achieve target heart rate. Statistical analysis employed independent t-test.

Results

KT recipients were 52.4±1.7 years old, 74.3% male, 91.4% white, 22.9% with diabetes, and 91.4% with hypertension. Controls were 54.4±2.0 years old, 74.3% male, 80% white, without diabetes, and 14.3% with hypertension. Baseline MCAv was similar in the two groups, but the response during moderate intensity exercise differed; CVR for KT recipients was 8.12 ± 0.8 cm/s compared to 12.9 ± 1.4 cm/s for controls (p=0.003) and target workload for KT recipients was 84.1 ± 2.8 watts compared to 123.1 ± 5.3 for controls (p<0.001) (Table 1).

Conclusion

KT recipients have a blunted middle cerebral artery hemodynamic response to exercise compared to healthy controls. This may be due to vascular disease and can explain the higher white matter disease, dementia, and stroke in this population.

Funding

  • Other NIH Support