Vascular Endothelial Growth Factor remains unchanged in cerebrospinal fluid of patients with Alzheimer's disease and vascular dementia

Background: Increasing evidence suggests that cerebral vascular dysfunction is associated with the early stages of Alzheimer's disease (AD). Vascular endothelial growth factor (VEGF) is one of the key players involved in the development and maintenance of the vasculature. Here, we hypothesized that VEGF levels in cerebrospinal fluid (CSF) may be altered in AD patients with vascular involvement, characterized by the presence of microbleeds (MB), and in vascular dementia (VaD) patients compared to controls. Methods: VEGF levels were determined by electrochemilumiscence Meso Scale Discovery (MULTI-SPOT Assay System) in CSF from age-matched groups of controls with subjective cognitive decline (n = 21), AD without MB (n = 25), AD with MB (n = 25), and VaD (n = 21) patients. Results: The average level of VEGF in the different groups was 2.8 +/- 1 pg/ml CSF. Adjusted for age and gender, no significant differences were detected between groups (p> 0.5). However, we detected a significant correlation between the concentration of VEGF in the CSF and age (r= 0.22, p = 0.03). In addition, males (n = 54) revealed higher VEGF levels in their CSF compared to females (n = 38) (males = 3.08 +/- 0.769 pg/ml (mean +/- SD), females = 2.6 +/- 0.59; p = 0.006), indicating a gender-related regulation. Conclusion: Our study suggests that VEGF levels in the CSF do not reflect the cerebral vascular alterations in either AD or VaD patients. The observed associations of VEGF with age and gender may indicate that VEGF reflects normal aging and that males and females may differ in their aging process.