Cognitive impairment and BDNF serum levels.
To investigate the alterations of brain-derived neurotrophic factor (BNDF) serum levels in subjects with different intensity of cognitive impairment and different neurodegenerative processes.



Serum BDNF levels were analyzed by ELISA kit in 378 subjects: 134 Alzheimer's disease (AD) patients, 115 amnestic mild cognitive impairment (MCI) patients, and 129 controls divided into two groups: neurodegenerative control group (ND), consisting of 49 Parkinson's disease patients without any cognitive complaints, and cognitively normal control group (CN), consisting of 80 subjects without any neurological disorders.



AD patients had significantly lower (p<0.001) BDNF serum levels compared to MCI, CN and ND controls. Age and education had significant influence on BDNF serum levels regardless the diagnosis or group assignment. We have found no influence of depression on BDNF serum levels either in our group as a whole, or in each group assessed separately. We found significant correlation between BDNF serum levels and cognitive impairments. After multiple comparisons between the groups, we found that, after adjustment for confounding factors (age, gender, education, depression, cognitive impairment), BDNF serum levels were the lowest in AD group (p=0.05).



Advanced age and low educational level are associated with decreased BDNF serum levels. Decreased BDNF serum levels correspond to the severity of cognitive impairment. There is no correlation between BDNF serum levels and depressive symptoms.
Department of Neurology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland; Department of Neurology, Central University Hospital, Katowice, Poland. Electronic address: jsiuda@sum.edu.pl.
Joanna
J
Siuda
Department of Neurology, Central University Hospital, Katowice, Poland.
Maja
M
Patalong-Ogiewa
Department of Neurology, Central University Hospital, Katowice, Poland.
Weronika
W
Żmuda
Department of Neurology, Central University Hospital, Katowice, Poland.
Magdalena
M
Targosz-Gajniak
Department of Biostatistics, School of Public Health in Bytom, Medical University of Silesia, Katowice, Poland.
Ewa
E
Niewiadomska
Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
Iwona
I
Matuszek
Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
Halina
H
Jędrzejowska-Szypułka
Joanna
J
Lewin-Kowalik
Department of Neurology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland; Department of Neurology, Central University Hospital, Katowice, Poland.
Monika
M
Rudzińska-Bar
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood*; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D060825:Cognitive Dysfunction / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood*; D012720:Severity of Illness Index
D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human
Alzheimer's disease; Brain-derived neurotrophic factor; Cognitive impairment; Dementia; Serum brain-derived neurotrophic factor level