BDNF serum concentrations in 2053 participants of the Berlin Aging Study II.

Serum BDNF concentrations in 2053 participants of the Berlin Aging Study II (BASE-II; 1572 individuals from the older age group [60-85 years], 481 individuals from the younger-age reference group [22-37 years]) were studied. There was no effect of age, sex, body mass index, self-reported depression, or BDNF Val66Met variant on serum BDNF concentrations. Multiple linear regression analysis failed to detect significant relationships of Digit Symbol Substitution Test score and Consortium to Establish a Registry for Alzheimer's Disease memory score to BDNF levels. However, we detected a positive correlation between platelet counts and BDNF levels (r = 0.303, p < 0.001). Our findings do not support an effect of aging, self-reported depression, or the Val66Met variant on serum BDNF concentrations. The role of thrombocytes in the biology of serum BDNF merits further study.