Peripheral arterial stiffness is correlated with intrarenal arteriolosclerosis according to biopsies from patients with kidney disease

Aim To investigate the possible associations between intrarenal arteriolosclerosis as determine by renal biopsy and endothelial function as well as arterial stiffness measured by peripheral arterial tonometry (EndoPAT). Methods This was a cross-sectional study. Patients who underwent both renal biopsy and EndoPAT were recruited, and intrarenal arteriolosclerosis was graded according to the pathological slice. Endothelial function and arterial stiffness were both measured by EndoPAT and were expressed by the reactive hyperemia index (RHI) and augmentation index (AIx), respectively. AIx@75, representing the AIx standardized to a heart rate of 75 bpm was also determined. Results In total, 113 patients were assessed, the mean age was 51 +/- 13, and 68.1% were men. The natural logarithm RHI (LnRHI), AIx and AIx@75 were significantly different among different grades of intrarenal arteriolosclerosis (P = .030, P < .001, P < .001, respectively). In the multivariable adjusted model, for every SD increase in the AIx and AIx@75, the odds of having more severe arteriolosclerosis were 2.506 times (95% confidence interval [CI] 1.464-4.288, P = .001] and 3.191 times (95% CI 1.780-5.719, P < .001) higher, respectively, and the association between the LnRHI and intrarenal arteriolosclerosis was nullified (P = .059). The positive values of the AIx and AIx@75 for the diagnosis of severe intrarenal arteriolosclerosis were 0.80 (95% CI 0.73-0.88, P < .001) and 0.78 (95% CI 0.70-0.87, P < .001), respectively. Conclusion Subjects with more severe intrarenal arteriolosclerosis have greater peripheral vascular stiffness; AIx and AIx@75 reflected peripheral vascular stiffness could be used to identify patients with severe intrarenal arteriolosclerosis.