Associations Between Vascular Risk Factors and Perivascular Spaces in Adults with Intact Cognition, Mild Cognitive Impairment, and Dementia

Background: Perivascular spaces (PVS) are fluid-filled compartments surrounding small intracerebral vessels that transport fluid and clear waste. Objective: We examined associations between PVS count, vascular and neurodegenerative risk factors, and cognitive status among the predominantly Hispanic participants of the FL-VIP Study of Alzheimer's Disease Risk. Methods: Using brain MRI (n = 228), we counted PVS in single axial image through the basal ganglia (BG) and centrum semiovale (CSO). PVS per region were scored as 0 (none), 1 (<10), 2 (11-20), 3 (21-40), and 4 (>40). Generalized linear models examined PVS associations with vascular risk factors and a composite vascular comorbidity risk (VASCom) score. Results: Our sample (mean age 72 +/- 8 years, 61% women, 60% Hispanic, mean education 15 +/- 4 years, 33% APOE4 carriers) was 59% hypertensive, 21% diabetic, 66% hypercholesteremic, and 30% obese. Mean VASCom score was 2.3 +/- 1.6. PVS scores ranged from 0-4 in the BG (mean 1.3 +/- 0.7) and CSO (mean 1.2 +/- 0.9), and 0-7 combined (mean 2.5 +/- 1.4). In multivariable regression models, BG PVS was associated with age (beta = 0.03/year, p < 0.0001), Hispanic ethnicity (beta = 0.29, p =0 .01), education (beta= 0.04/year, p = 0.04), and coronary bypass surgery (beta = 0.93, p = 0.02). CSO PVS only associated with age (beta = 0.03/year, p < 0.01). APOE4 and amyloid-beta were not associated with PVS. Conclusion: BG PVS may be a marker of subclinical cerebrovascular disease. Further research is needed to validate associations and identify mechanisms linking BG PVS and cerebrovascular disease markers. PVS may be a marker of neurodegeneration despite our negative preliminary findings and more research is warranted. The association between BG PVS and Hispanic ethnicity also requires further investigation.