Early carotid pulse waves are associated with an acceleration of 18 F-FDG PET hypometabolism in Alzheimer’s brain areas

Abstract

Abstract Background Arterial stiffening likely plays a role in Alzheimer disease (AD) pathogenesis and may also favour a potentially deleterious early return of reflected arterial pressure waves. The current study investigated whether inter-individual variations in arterial stiffness and pressure wave parameters were associated with 18F-FDG positron emission tomography (PET) metabolism in AD-associated brain areas independently of age and before the onset of any neuropsychological disorders.Methods A prospective, large age-range population of 67 patients (17 young, 16 middle-aged, and 34 older adults; 37 women) with normal neuropsychological tests, underwent a: 1) brain 18F-FDG PET, 2) blood pressure recording and 3) carotid/femoral pulse wave-based measurements, including the time-to-peak of the reflected backward carotid pulse wave (bT), on the same day. Multivariate and quantitative voxel-to-voxel analyses (p-voxel < 0.005, corrected for cluster volumes) were conducted to assess associations between vascular parameters and 18F-FDG PET metabolism in AD-associated brain areas.Results In the multivariate analysis, only increased age and decreased bT were independently associated with the decline of metabolic activity in AD-associated brain areas (p < 0.001). In the voxel-to-voxel analysis with age as a covariate, bT was strongly associated with the metabolic activity of 40 clusters in AD-associated brain areas (clusters cumulative volume: 63 cm3; T score max: 5.7).Conclusion In patients, who are still unaffected by neuropsychological disorders, an early reflected arterial pressure wave, as evidenced by a decreased bT value, is strongly associated with an acceleration of the age-related decline in the metabolic activity of AD-associated brain areas.Trial registration : This research study was approved by the local ethics committee (CPP accreditation N°2018/26; date of registration : May,11th 2018).