P2‐134: Clinical characteristics of subjects with conflicting biomarkers of amyloid deposition

HLD history, amyloid positivity (positive is SUVR>1.1), and the interaction of these variables. mH were analyzed by number of regions showing mH (0, 1, 2, 3, 4, 5+) and by presence/absence of mH. Linear regression and chi-square models were used to assess the relationship of HLD history and amyloid positivity to mH, covaried for age. Results: Both amyloid positivity and HLD history were independently associated with presence/absence and number of regions showing mH (all p<0.05). Participants who were both positive for HLD history and amyloid showed the highest rate of mH positivity (39.2%), relative to those positive for only HLD history (22.5%), only amyloid positivity (28.5%), and those showing neither risk factor (19.3%). These effects were independent of baseline diagnostic group, gender, and APOE ε4 genotype. Conclusions: HLD and amyloid deposition are independent risk factors for mH and show an additive effect such that older adults who are both amyloid positive and have a history of HLD have the highest prevalence and number of mH. Future studies of the clinical implications and underlying mechanisms of these effects are warranted. References: [1] Kantarci et al. (2013) Alz & Dem, 9(5 Supp): S116-23. [2] Landau et al. (2013) J Nucl Med, 54(1): 70-77.