Serum brain-derived neurotrophic factor: Determinants and relationship with depressive symptoms in a community population of middle-aged and elderly people

Abstract

ObjectivesBrain-derived neurotrophic factor (BDNF) is involved in major depressive disorder and neurodegenerative diseases. Clinical studies, showing decreased serum BDNF levels, are difficult to interpret due to limited knowledge of potential confounders and mixed results for age and sex effects. We explored potential determinants of serum BDNF levels in a community sample of 1230 subjects.MethodsMultiple linear regression analyses with serum BDNF level as the dependent variable were conducted to explore the effect of four categories of potential BDNF determinants (sampling characteristics, sociodemographic variables, lifestyle factors and somatic diseases) and of self-reported depressive symptoms (Beck's Depression Inventory (BDI).ResultsOur results show that BDNF levels decline with age in women, whereas in men levels remain stable. Moreover, after controlling for age and gender, the assays still showed lower serum BDNF levels with higher BDI sum scores. Effects remained significant after correction for two main confounders (time of sampling and smoking), suggesting that they serve as molecular trait factors independent of lifestyle factors.ConclusionsGiven the age-sex interaction on serum BDNF levels and the known association between BDNF and gonadal hormones, research is warranted to delineate the effects of the latter interaction on the risk of psychiatric and neurodegenerative diseases.

BDNF Val66Met polymorphism and serum concentrations of BDNF with smoking in Thai males

“…Peripheral BDNF levels are widely used as an indicator of the same brain parameter (Karege et al, 2002), but the regulation of BDNF levels in the peripheral blood is not fully understood (Gass and Hellweg, 2010). Recent studies with large sample sizes revealed that current smokers had significantly higher serum BDNF levels than non-smokers (Zhang et al, 2010;Bus et al, 2011Bus et al, , 2012. These findings have been confirmed by this study.…”

Relationship Between Hippocampal Volume, Serum BDNF, and Depression Severity Following Electroconvulsive Therapy in Late-Life Depression

“…This could well be related to an age-related decrease in sBDNF levels. In our sample, the mean sBDNF level was 18.27 ng/ml, which is in line with earlier reports of elderly populations (Erickson et al, 2010;Bus et al, 2012;Rapinesi et al, 2015) but lower compared with levels ranging from 9.5 to 29.0 μg/ml in non-elderly depressed patients (Sen et al, 2008). Differences in the sBDNF level could also be explained by sample characteristics and protocols used (eg, urbanicity, sex, smoking status, time of blood withdrawal, and so on; Bus et al, 2011).…”

“…Although BDNF can have a crucial role in the development of depression and its recovery (Molendijk et al, 2013;Bus et al, 2012Bus et al, , 2015, our study seems to indicate that improvements in depression and sBDNF are unrelated. The inability to elevate sBDNF levels following ECT could be because of an age-related less responsive BDNF system (Calabrese et al, 2013;Rapinesi et al, 2015).…”

“…We hypothesized that, given the decrease in both sBDNF and hippocampal volume in depression (Bus et al, 2012;Erickson et al, 2012;Sexton et al, 2013), ECT would increase the level of sBDNF, which would be associated with an increase in hippocampal volume, and subsequent positive treatment response.…”

Prediction of Depression in Schizophrenia: Can serum Levels of BDNF or EGF Help us?

“…Some of the previous studies reported that clinical determinants such as sex, smoking status, drinking behaviour and age can affect serum BDNF levels [28,29], however some did not report such association [7,21,23]. In the present study, we did not find any significant correlation between the serum BDNF levels and sex, age, age of onset, or body mass index, number of relapses in the patient groups.…”