Cerebrospinal Fluid Irisin Correlates with Amyloid‐β, BDNF, and Cognition in Alzheimer's Disease

Introduction: Irisin is a novel hormone originally identified for its role as a regulator of peripheral metabolism and recently found to protect synapses and rescue memory in mouse models of Alzheimer's disease (AD). However, whether and how cerebrospinal fluid (CSF) irisin varies in relation to canonical AD biomarkers and cognition in humans remains unknown. Methods: We determined CSF levels of irisin and brain-derived neurotrophic factor (BDNF) and examined their correlations with CSF amyloid beta (A beta)(42), total tau, and Mini-Mental State Exam (MMSE) scores in a cohort comprising AD patients (n = 14) and non-demented controls (NDC; n = 25). Results: CSF irisin correlated positively with BDNF, A beta(42), and MMSE scores, but not with CSF total tau. Discussion: Results indicate that CSF irisin and BDNF are directly correlated with A beta pathology and cognition in AD.