Brachial Artery Retrograde and Oscillatory Shear are Increased in Patients with Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have increased risk of cardiovascular disease (CVD). Endothelial function, a nontraditional CVD risk factor and known independent predictor of CVD, is markedly reduced in CKD. Disturbed blood flow patterns (i.e. retrograde and oscillatory shear stress) can impair endothelial function and induce a proatherogenic endothelial cell phenotype. However, resting blood flow patterns in CKD patients have not been fully evaluated and thus was the objective of this investigation. We hypothesized patients with CKD would have altered shear patterns compared to healthy, age-matched controls. 44 patients with CKD (61% female; mean±SE: age 66±1 y; eGFR 44±2 mL/min/1.73 m2) and 44 healthy aged-matched controls (CON, 64% female; mean±SE age 64±1 y; eGFR 85±2 mL/min/1.73 m2) were included in the study. High resolution doppler ultrasound was used to assess resting brachial artery diameter and blood velocity to calculate antegrade and retrograde blood flow and shear rate. Oscillatory shear index was calculated using the following formula: (|retrograde shear rate|)/ (|antegrade shear rate| + |retrograde shear rate|). Resting antegrade shear rate was not different between CKD and CON (145±10 s-1 vs. 129±7 s-1, P=0.2). However, resting retrograde shear rate and oscillatory shear index were greater in CKD vs. CON (Retrograde shear rate: -44± 4 s-1 vs. -32± 3 s-1, P=0.02; oscillatory shear index: 0.22±0.01 au vs. 0.19± 0.01 au, P=0.02). The difference in retrograde shear rate and oscillatory shear index between CKD and CON persisted after statistically adjusting for systolic blood pressure. In conclusion, patients with CKD demonstrate altered shear patterns compared to age-matched controls, which may be a physiological mechanism contributing to reduced endothelial function in patients with CKD. This work was supported by: NIH NIDDK and the American Society of Nephrology This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.