Vascular Function And Progression Of Alzheimer’s Disease

Abstract

PURPOSE: In aging, cerebral and systemic vascular functions (VF) decline likewise to cognitive decline. Also, reduced availability of nitric oxide (NO) in both cerebral and peripheral blood vessels results in further alterations of VF. So, changes in VF and NO availability may contribute to the development of Alzheimer’s disease (AD). However, current literature lacks of evidence about the progression of AD and VF. To verify if VF is significantly reduced in AD patients compared with age-matched healthy counterparts and if VF declines further with the severity of AD. Potential correlation between VF and NO availability was also assessed. METHODS: In 55 AD patients (severity of dementia distribution: 12 MCI, 15 AD1, 19 AD2, 9 AD3), 13 healthy elderly (OLD), and 10 young (YG) subjects systemic vascular function was assessed by means of passive limb movement (PLM). NO availability was determined via plasma NO metabolites (NO-3+NO-2). RESULTS: Δpeak PLM was 739±150 ml/min, 284±46 ml/min, 227±39, 182±37 ml/min, 166±22 ml/min, 155±26 ml/min in YG, OLD, MCI, AD1, AD2, and AD3 respectively. NO-3+NO-2 was 53±9 μM, 47±3 μM, 42±2 μM, 40±3 μM, 38±3 μM, 35±1 μM in YG, OLD, MCI, AD1, AD2, and AD3 respectively. Correlation between Δpeak PLM and NO-3+NO-2 was r=0.9765. CONCLUSION: Our results confirm that VF is reduced in aging. AD patients exhibited a further reduction of VF compared with healthy age-matched counterparts. Moreover, VF and NO availability were progressively declined with the progression of dementia, implicating that AD and its progression might be the result of an intertwined decline of both neural and vascular functions, likely related to the NO availability.