NEFL and Alzheimer disease: Previous studies have reported elevated levels of plasma NfL among study participants with Alzheimer’s disease or MCI compared to healthy controls.25,27, -29,83,84 Although the present study did not find that plasma NfL was elevated in the vMCI group compared to controls, it is important to consider that the control group in this study shared a similarly high vascular risk profile (eg, diabetes, hypertension, and CAD).