Brain-derived neurotrophic factor serum levels in genetically isolated populations: gender-specific association with anxiety disorder subtypes but not with anxiety levels or Val66Met polymorphism.

Davide Carlino,Karolina Kulak,Gabriele Baj,Pio d’Adamo,Ruggiero Francavilla,Paolo Gasparini,Sheila Ulivi,Stefania Cappellani,Enrico Tongiorgi

doi:10.7717/peerj.1252

Davide Carlino, Karolina Kulak + Show 7 more

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https://doi.org/10.7717/peerj.1252

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Abstract

Anxiety disorders (ADs) are disabling chronic disorders with exaggerated behavioral response to threats. This study was aimed at testing the hypothesis that ADs may be associated with reduced neurotrophic activity, particularly of Brain-derived neurotrophic factor (BDNF), and determining possible effects of genetics on serum BDNF concentrations. In 672 adult subjects from six isolated villages in North-Eastern Italy with high inbreeding, we determined serum BDNF levels and identified subjects with different ADs subtypes such as Social and Specific Phobias (PHSOC, PHSP), Generalized Anxiety Disorder (GAD), and Panic Disorder (PAD). Analysis of the population as a whole or individual village showed no significant correlation between serum BDNF levels and Val66Met polymorphism and no association with anxiety levels. Stratification of subjects highlighted a significant decrease in serum BDNF in females with GAD and males with PHSP. This study indicates low heritability and absence of any impact of the Val66Met polymorphism on circulating concentrations of BDNF. Our results show that BDNF is not a general biomarker of anxiety but serum BDNF levels correlate in a gender-specific manner with ADs subtypes.

Highlights

Anxiety disorders (ADs) are disabling medical disorders affecting 6% of men and 13% of women in the USA and 21% of the general population in Italy and France (US Census Bureau, 2005; Alonso et al, 2004; Kessler et al, 2005a; Kessler et al, 2005b; Leray et al, 2011).How to cite this article Carlino et al (2015), Brain-derived neurotrophic factor serum levels in genetically isolated populations: gender-specific association with anxiety disorder subtypes but not with anxiety levels or Val66Met polymorphism
To determine whether there was any significant difference related to gender, Brain-derived neurotrophic factor (BDNF) levels were compared in males and females in both healthy donors (HD) and AD groups (Fig. 1B)
Mann–Whitney U test comparison between HD and AD males showed no significant difference in BDNF levels (p = 0.225); and no significant difference was found in female subjects between the two study groups (p = 0.067)

Summary

Introduction

Anxiety disorders (ADs) are disabling medical disorders affecting 6% of men and 13% of women in the USA and 21% of the general population in Italy and France (US Census Bureau, 2005; Alonso et al, 2004; Kessler et al, 2005a; Kessler et al, 2005b; Leray et al, 2011).How to cite this article Carlino et al (2015), Brain-derived neurotrophic factor serum levels in genetically isolated populations: gender-specific association with anxiety disorder subtypes but not with anxiety levels or Val66Met polymorphism. Anxiety disorders (ADs) are disabling medical disorders affecting 6% of men and 13% of women in the USA and 21% of the general population in Italy and France (US Census Bureau, 2005; Alonso et al, 2004; Kessler et al, 2005a; Kessler et al, 2005b; Leray et al, 2011). ADs comprise a collection of syndromes characterized by exaggerated fear responses to perceived threats. Such threats extend to a wide range of situations in Generalized Anxiety Disorder (GAD), and to specific ones, such as social evaluation in Social Phobia (PHSOC). ADs commonly occur along with other mental or physical illnesses, including mood disorders and alcohol or substance abuse, which may mask anxiety symptoms or make them worse (Yu et al, 2013)

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