PECAM1 and Hypertension: Increased ratio of the levels of circulating CD31+/annexin V+ EMPs to EPCs is associated with subsequent declines in GFR in hypertensive patients, and levels of circulating CD31+/Annexin V+ EMPs significantly predict the degree of urinary albumin excretion rate in humans with hypertension [24], suggesting a vicious cycle of microparticles on injured endothelium in hypertensive patients with nephropathy.