REN and chronic kidney disease: Potential biological mechanisms underlying the relationship between visit-to-visit BPV and CKD may include fluctuations in renal blood flow, changes in aortic hypertrophy and remodeling, onset of endothelial dysfunction, activation of the renin–angiotensin system, activation of inflammatory cytokines, changes in oxidative stress or extracellular matrix deposition, and onset of glomerular sclerosis [48–52].