Relationships between diabetes-related vascular risk factors and neurodegeneration biomarkers in healthy aging and Alzheimer's disease

Vascular risk factors such as hyperglycemia and platelet hyperactivation play a significant role in type 2 diabetes (T2D), a risk factor for AD. We investigated the relationships between glycemia levels, platelet indices (platelet count; mean platelet volume (MPV)) and AD neuroimaging markers in 105 cognitively unimpaired adults, including 21 amyloid-negative older adults (A beta-neg controls), and 45 amyloid-positive patients with mild cognitive impairment or dementia (A beta-pos patients). We assessed between-group differences on the two T2D-related vascular risk factors, then the association between blood parameters and multimodal neuroimaging (structural MRI, F-18-fluorodeoxyglucose, and F-18-florbetapir-PET) in cognitively unimpaired adults and A beta-pos patients using multiple regressions. Compared to A beta-neg controls, A beta-pos patients showed lower platelet count and higher MPV. In cognitively unimpaired adults, increased glycemia levels were associated with atrophy and hypometabolism in AD-sensitive regions. In A beta-pos patients, increased MPV was associated with entorhinal and perirhinal cortex atrophy. Subclinical but high glycemia levels in healthy individuals and MPV in AD patients are associated with neurodegeneration in AD-sensitive brain regions but not with amyloid deposition. (c) 2022 The Author(s). Published by Elsevier Inc.

Automated summary

The study indicates a significant relationship between vascular risk factors such as hyperglycemia and platelet hyperactivation and type 2 diabetes (T2D) and Alzheimer's disease (AD). Higher glycemia levels are associated with neurodegeneration in cognitively unimpaired adults and AD patients, while increased mean platelet volume (MPV) is linked to specific brain region atrophy in AD patients.