CD34 and Alzheimer disease: In contrast to positive associations with some vascular diseases, with an increase in the CD34+CD133+ EPC quartiles, the incident rates of AD (5.85% vs. 3.94% vs. 2.99% vs. 2.09%, P = 0.04) and all-cause dementia (7.66% vs. 5.56% vs. 4.41% vs. 2.86%, P = 0.02) decreased (Table 3).