In the original analysis, the plasma TTR level was an independent factor for the MCI conversion to AD (p = 0.023, 95% CI 1.001–1.007), as well as age (p = 0.006, 95% CI 1.021–1.136), sex (p = 0.036, 95% CI 1.043–3.429), baseline MMSE scores (p = 0.002, 95% CI 0.762–0.939), and APOE ɛ4 carrier status (p = 0.001, 95% CI 1.560–5.545). Here, APOE is linked to Alzheimer disease.