Irisin and BDNF serum levels and behavioral disturbances in Alzheimer's disease

Behavioral dysfunctions (BPSD) represent the most important problem in Alzheimer's dementia (AD) management. We assessed the serum levels of two myokines in AD patients, preliminary investigating, as secondary aim, their role as potential biomarkers for agitation/aggression (AA) and aberrant motor behavior (AMB): irisin, since it is able to modify the motor pattern, and BDNF, since it was transcribed following irisin stimulation. Forty AD patients were recruited and characterized according to the expressed neuropsychiatric syndrome. Myokines were measured by ELISA. Irisin serum levels were slightly elevated in AA+ patients (+ 10.0%; p < 0.05) and correlated with the duration of AA (r = 0.74, p < 0.03). BDNF failed to show such differences. We propose that these selected myokines are not useful as surrogate markers for agitation in AD, but might represent interesting secondary outcomes when testing drugs for those BPSD implying elevated motor activity.