Background: White matter (WM) beta-amyloid uptake has been used as a reference region
to calculate the cortical standard uptake value ratio (SUVr). However, white matter hyperintensities
(WMH) may have an influence on WM beta-amyloid uptake. Our study aimed to investigate
the associations between WMH and WM beta-amyloid deposition in cognitively unimpaired
Methods: Data from 83 cognitively unimpaired individuals in the Alzheimer’s Disease Neuroimaging
Initiative (ADNI) dataset were analyzed. All participants had complete baseline and four-year
follow-up information about WMH volume, WM 18F-AV-45 SUVr, and cognitive function, including
ADNI-Memory (ADNI-Mem) and ADNI-Executive function (ADNI-EF) scores. Cross-sectional
and longitudinal linear regression analyses were used to determine the associations between
WMH and WM SUVr and cognitive measures.
Results: Lower WM 18F-AV-45 SUVr at baseline was associated with younger age (β=0.01,
P=0.037) and larger WMH volume (β=-0.049, P=0.048). The longitudinal analysis found an annual
increase in WM 18F-AV-45 SUVr was associated with an annual decrease in WMH volume
(β=-0.016, P=0.041). An annual decrease in the ADNI-Mem score was associated with an annual
increase in WMH volume (β=-0.070, P=0.001), an annual decrease in WM 18F-AV-45 SUVr
(β=0.559, P=0.030), and fewer years of education (β=0.011, P=0.044). There was no significant association
between WM 18F-AV-45 SUVr and ADNI-EF (P>0.05).
Conclusion: Reduced beta-amyloid deposition in WM was associated with higher WMH load and
memory decline in cognitively unimpaired elderly. WMH volume should be considered when WM
18F-AV-45 SUVr is used as a reference for evaluating cortical 18F-AV-45 SUVr.