Amariglio R, Wadsworth L, Lorius N, Becker A, Johnson K, Sperling R, Rentz D.
Subjective Cognitive Complaint Is Associated with Increased Amyloid Burden in Cognitively Normal Individuals.Human Amyloid Imaging Abstract.
2012 Jan 1;
Background: Accumulating evidence suggests that subjective cognitive complaint (SCC) may represent one of the earliest behavioral changes heralding risk for future cognitive decline due to Alzheimerfs disease (AD). Furthermore, associations between SCC and a variety of AD biomarkers have been found in cognitively normal (CN) individuals but not with amyloid imaging and standardized measures of SCC.
Objective: We sought to determine whether SCC is associated with cortical amyloid burden using Positron Emission Tomography with Pittsburgh Compound B (PiB PET) in CN individuals and with more extensive behavioral measures than used previously.
Methods: Ninety four CN individuals (CDR = 0, MMSE .27) underwent PiB PET imaging and behavioral assessments of SCC including the Everyday Cognition Scale (E-Cog), Memory Function Questionnaire (MFQ), the seven subjective questions (7 Questions) that were previously reported as identifying cognitive impairment in SCC, as well as the Selective Reminding Test (SRT) and Geriatric Depression Scale (GDS). Amyloid deposition was assessed using PiB PET DVR with an aggregate of cortical regions. Multivariate models related PiB retention to the three different SCC questionnaires separately, each controlling for age. Secondary analyses covarying for SRT, GDS, and APOE status were also performed.
Results: Higher PiB retention was associated with greater SCC in two of the behavioral measures (E-Cog: beta=5.11, p=0.01; Questions: beta=1.55, p=0.012) and at trend level for the third (MFQ: beta= -0.81, p=0.06). The relationship between PiB and SCC for the E-Cog and Questions remained significant when SRT and GDS were included as covariates. APOE status did not mediate the relationship between SCC and PiB.
Conclusions: These results suggest that SCC is associated with greater amyloid burden, unrelated to objective memory performance or depressive symptoms in CN. SCC may assist detection of the earliest cognitive changes in preclinical AD, particularly when more extensive and targeted instruments are used.