Vascular risk modulates the relationship between cerebral amyloid deposition and subjective memory complaints

PURPOSE: We aimed to investigate the relationships of cerebral amyloid beta (Aβ) deposition and neurodegeneration (ND) with subjective memory complaints (SMCs) in cognitively normal (CN) individuals, focusing specially on the modulating effects of vascular risk (VR) on those relationships. PARTICIPANTS AND METHODS: A total of 230 CN elderly individuals underwent comprehensive clinical assessments including the Subjective Memory Complaints Questionnaire (SMCQ), VR assessment, and multimodal brain imaging including [(11)C] Pittsburgh compound B positron emission tomography (PET), [(18)F] fluorodeoxyglucose-PET, and magnetic resonance imaging. RESULTS: We found a significant overall positive association between cerebral Aβ retention and SMCQ score. In addition, we found a significant cerebral Aβ retention × VR interaction effect on the SMCQ score. Subgroup analyses showed that the Aβ–SMC association was found only in VR-negative, and not in VR-positive, individuals. We found no relationship between ND and SMCQ. CONCLUSION: Our findings suggest that SMC in CN elderly individuals reflects early accumulation of Aβ in the brain. Given the modulating effect of VR on the Aβ–SMC relationship, SMC can be used as a meaningful marker of early Aβ deposition in individuals without VR.