Vascular risk factors and astrocytic marker for the glymphatic system activity

Objectives Glymphatic system maintains brain fluid circulation via active transportation of astrocytic aquaporin-4 in perivascular space. The diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) is an established method measuring perivascular glymphatic activity, but comprehensive investigations into its influential factors are lacking. Methods Community-dwelling older adults underwent brain MRI scans, neuropsychiatric, and multi-domain assessments. Blood biomarker tests included glial fibrillary acidic protein (GFAP) for astrocyte injury. Results In 71 enrolled participants, the DTI-ALPS index was associated with modifiable factors, including lipid profile (high-density lipoprotein, r = 0.396; very-low-density lipoprotein, r = − 0.342), glucose intolerance (diabetes mellitus, standardized mean difference (SMD) = 0.7662; glycated hemoglobin, r = − 0.324), obesity (body mass index, r = − 0.295; waist, r = − 0.455), metabolic syndrome (SMD = − 0.6068), cigarette-smoking (SMD = − 0.6292), and renal clearance (creatinine, r = − 0.387; blood urea nitrogen, r = − 0.303). Unmodifiable associative factors of DTI-ALPS were age ( r = − 0.434) and sex (SMD = 1.0769) (all p