Abstract P152: Low Memory Recall And High Common Carotid Artery Flow Pulsatility In Non-Dialysis Chronic Kidney Disease Patients

Abstract

A significant proportion of patients with non-dialysis chronic kidney disease (CKD) present with mild-to-moderate deficits in the cognitive domains of executive function and episodic memory. Excess blood flow pulsatility is damaging to the microvasculature of high-flow, low-resistance organs like the brain and may contribute to the cognitive deficits prevalent among CKD patients. We tested the hypothesis that patients with moderate-to-severe non-dialysis CKD have excess flow pulsatility along their carotid and cerebral vasculature that is associated with deficits in executive function and episodic memory. We recruited 10 non-dialysis CKD patients (age=68±8 yrs; estimated glomerular filtration rate, eGFR=36±18 mL/min/1.73 m 2 ) and 7 healthy age-matched adults (age=65±5 yrs; eGFR=81±17 mL/min/1.73 m 2 ). Global cognitive function was assessed with the Montreal Cognitive Assessment (MoCA). Executive function and episodic memory were assessed using the NIH Toolbox Flanker Inhibitory Control and Attention Test and California Verbal Learning Test III, respectively, and reported as standardized scores (mean=100, SD=15). Pulsatility index [(systolic blood velocity - diastolic blood velocity)/ mean blood velocity] was measured in the common carotid (CCA), internal carotid (ICA), and middle cerebral arteries (MCA) via Doppler and transcranial Doppler ultrasound. Compared to healthy adults, CKD patients did not differ in total brain blood flow (p=0.42) but had lower MoCA (CKD=26±3, Healthy=29±1; p=0.01) and memory recall scores (CKD=92±21, Healthy=110±9; p=0.05). CKD patients did not differ from our healthy control group in executive function (CKD=91±10, Healthy=90±11; p=0.80) but did produce a mean score that was 0.6 SD lower than the NIH Toolbox reference sample. CKD patients had a higher pulsatility index in the CCA (CKD=2.3±0.5, Healthy=1.9±0.3; p=0.05) but not in the ICA (p=0.68) or MCA (p=0.57). CCA pulsatility index was strongly and inversely associated with episodic memory recall scores (r=-0.64, p<0.01, n=17). This data suggests that although the higher CCA flow pulsatility in non-dialysis CKD patients does not appear to be transmitted to the cerebrovasculature, it nevertheless may still be contributing to memory impairments.