Fig. 2

Correlations of plasma markers with demographic features. Demographic factors (age, sex, education, and APOE ε4 status) correlated to plasma measures (log-converted) were analyzed using multiple linear regressions. When one of the demographic factors was analyzed as a predictor variable, the other three factors were included in the model as covariates. The dotted gray lines from the center to the periphery represented the derived correlation coefficient (β) ranging from −0.080 to 0.405 in the CU A−T− and the whole Alzheimer’s continuum (CU A+T−, CU A+T+, MCI+, and AD dementia) groups (A) and from -0.161 to 0.271 in the CU A−T− and preclinical AD (CU A+T−, CU A+T+) groups (B). The * indicated the FDR-corrected p<0.05. C Scatter plots showing the associations of each plasma biomarker with age in the CU A−T− and preclinical AD groups. The standardized regression coefficients (β) and the P-values were computed using multiple linear regressions adjusting for sex, education, and APOE ε4 status. Additionally, we calculated the “age×Aβ status” interaction term. All P-values are corrected for multiple comparisons using the FDR approach. Abbreviations: APOE, apolipoprotein E; MCI, mild cognitive impairment; AD, Alzheimer’s disease; FDR, false discovery rate; Αβ, amyloid-β; GFAP, glial fibrillary acidic protein; NfL, neurofilament light; p-tau, phosphorylated tau