Blood Brain-derived Neurotrophic Factor Concentrations Research Articles

Blood levels of brain-derived neurotrophic factor (BDNF) in systemic lupus erythematous (SLE): a systematic review and meta-analysis

ObjectivesBDNF has been implicated in the pathophysiology of systemic lupus erythematosus (SLE), especially its neuropsychiatric symptoms. The purpose of this study was to investigate the profile of blood BDNF levels in patients with SLE.MethodsWe searched PubMed, EMBASE, and the Cochrane Library for papers that compared BDNF levels in SLE patients and healthy controls (HCs). The Newcastle–Ottawa scale was used to assess the quality of the included publications, and statistical analyses were carried out using R 4.0.4.ResultsThe final analysis included eight studies totaling 323 healthy controls and 658 SLE patients. Meta-analysis did not show statistically significant differences in blood BDNF concentrations in SLE patients compared to HCs (SMD 0.08, 95% CI [ − 1.15; 1.32], P value = 0.89). After removing outliers, there was no significant change in the results: SMD -0.3868 (95% CI [ − 1.17; 0.39], P value = 0.33. Univariate meta-regression analysis revealed that sample size, number of males, NOS score, and mean age of the SLE participants accounted for the heterogeneity of the studies (R2 were 26.89%, 16.53%, 18.8%, and 49.96%, respectively).ConclusionIn conclusion, our meta-analysis found no significant association between blood BDNF levels and SLE. The potential role and relevance of BDNF in SLE need to be further examined in higher quality studies.

High maternal BMI and low maternal blood BDNF may determine the limit of detection of amniotic fluid BDNF throughout gestation: Analysis of mother-fetus trios and literature review

ObjectiveAn increasing number of studies show the importance of brain-derived neurotrophic factor (BDNF) acting at the feto-placental interface, however, only a few studies describe BDNF levels in amniotic fluid (AF).MethodsIn this cross-sectional, prospective study, 109 maternal blood-amniotic fluid pairs (including 66 maternal blood-fetal-blood-amniotic fluid trios) were analyzed. BDNF concentrations were measured with a commercially available immunoassay.ResultsIn 71 AF from 109 samples, AF-BDNF concentrations were below the lowest limit of Quantitation (LLoQ) of 1.19 pg/ml (group A), leaving 38 samples with measurable BDNF concentrations (group B). Patients in group A showed significantly higher maternal BMI before pregnancy (mean±SD 26.3± 6.7 (kg/m2) vs. 23.8 ±4.5 (kg/m2) p = 0.04) and lower maternal blood BDNF concentrations than the other group (mean±SD 510.6 ± 554.7 pg/ml vs. mean±SD 910.1± 690.1 pg/ml; p<0.0001). Spearman correlation showed a negative correlation between maternal BMI before pregnancy and maternal BDNF concentrations (r = -0.25, p = 0.01).ConclusionOur study is the first to correlate AF-BDNF samples with the corresponding maternal and fetal blood-BDNF samples. The significant negative correlation between maternal BMI before pregnancy and maternal BDNF and AF-BDNF concentrations below the limit of detection has to be evaluated in further studies.

Association of neonatal blood levels of brain-derived neurotrophic factor with development of autism spectrum disorder: a systematic review and meta-analysis.

Our goal was to evaluate the association between neonatal blood brain-derived neurotrophic factor (BDNF) level and autism spectrum disorder (ASD) diagnosis later in life. MEDLINE and Web of Science databases were searched from inception until September 16, 2020. Reference lists of all relevant articles also were reviewed. Mean blood BDNF concentrations, standard deviations, sample sizes, and other data needed for calculation of effect sizes were extracted by two independent investigators. The quality of the included studies was appraised using the Newcastle-Ottawa Scale for case-control studies. Data were pooled using the random-effects model. Five case-control studies involving 1341 cases and 3395 controls were included in the meta-analysis. The meta-analysis of all included studies showed no significant difference in blood BDNF levels between neonates diagnosed with ASD later in life and healthy controls [standardized mean difference (SMD) = 0.261; 95% confidence interval (CI) - 0.052 to 0.573; P = 0.102], with high level of heterogeneity (Q = 64.346; I2 = 93.784; P < 0.001). A subgroup analysis by assay type showed decreased blood BDNF levels in ASDs compared to controls (SMD = - 0.070; 95% CI - 0.114 to - 0.026; P = 0.002), with high level of homogeneity (Q = 0.894; I2 = 0.000; P = 0.827). No evidence of publication bias was observed. Neonates diagnosed with ASD later in life have decreased blood levels of BDNF measured by double-antibody immunoassay. More studies are warranted to facilitate a more robust conclusion.

Ejercicio y algunos mecanismos moleculares que subyacen a una mejora del desempeño en tareas cognitivas

Potenciar el aprendizaje y la memoria se ha convertido en una tarea de interés para muchos investigadores. Artículos recientes han podido comprobar es que el ejercicio es una clara herramienta para mejorar capacidades cognitivas de personas y animales gracias a que favorece la liberación de sustancias tales como neurotransmisores y factores neurotróficos. Uno de los factores más importantes es el factor neurotrófico derivado del cerebro (BDNF), que promueve la generación de cambios a nivel neuronal necesarios para la potenciación a largo plazo (fortalecimiento de memorias). Se realizó una búsqueda en las bases de datos de EBSCOhost -en las bases de Academic Search Complete, ERIC, MEDLINE, PsycARTICLES y SPORTDiscus-, Google Scholar, Pubmed y ScienceDirect utilizando una serie de palabras con sus respectivos criterios de inclusión y exclusión. En este trabajo se explican los procesos asociados con la potenciación a largo plazo, abarcando temas como neuroplasticidad, la unión del BDNF con su receptor (receptores de tirosina quinasa B), y además el mecanismo por medio del cual la liberación de la mioquina irisina, como una consecuencia del ejercicio, promueve el aumento de las concentraciones de BDNF en sangre. Basándose en numerosa literatura se describe la relación que existe entre el ejercicio y la generación de cambios neuroplásticos estimulados por proteínas como el BDNF y la consecuente mejoría en la memoria.

The Impact of Different Types of Exercise Training on Peripheral Blood Brain-Derived Neurotrophic Factor Concentrations in Older Adults: A Meta-Analysis.

As the prevalence of neurodegenerative diseases (such as dementia) continues to increase due to population aging, it is mandatory to understand the role of exercise for maintaining/improving brain health. To analyse the impact of aerobic, strength and combined aerobic/strength exercise training on peripheral brain-derived neurotrophic factor (BDNF) concentrations in older adults (minimum age 60years). This meta-analysis adhered to PRISMA guidelines. Inclusion criteria were: (i) studies with subjects aged ≥ 60years, (ii) completing a single exercise bout or an exercise programme, with (iii) measurements of blood BDNF in the periphery; (iv) with comparison between (a) an intervention and control group or (b) two intervention groups, or (c) pre- and post-measurements of an exercise intervention without control group. Studies with specific interest in known chronic co-morbidities or brain diseases affecting the peripheral and/or central nervous system, except for dementia, were excluded. In general, peripheral blood BDNF concentrations increased significantly after a single aerobic/strength exercise bout (Z = 2.21, P = 0.03) as well as after an exercise programme (Z = 4.72, P < 0.001). However, when comparing the different types of exercise within these programmes, the increase in the peripheral BDNF concentrations was significant after strength training (Z = 2.94, P = 0.003) and combined aerobic/strength training (Z = 3.03, P = 0.002) but not after (low-to-moderate intense) aerobic exercise training (Z = 0.82, P = 0.41). Based on current evidence, to increase the peripheral blood BDNF concentrations in older adults, strength training and combined aerobic/strength training is effective. More studies are needed to examine the impact of aerobic exercise training.

Effect of maternal iron deficiency anemia on fetal neural development.

Perinatal iron deficiency may have deleterious consequences on fetal neural development. The present study was conducted to determine the effect of maternal iron deficiency anemia (IDA) on fetal hippocampal morphogenesis and production of brain-derived neurotrophic factor (BDNF). Seventy term, singleton neonates born to mothers with IDA (hemoglobin <110g/L and serum ferritin <12 μg/L) formed the study group. Twenty gestational age-matched neonates born to healthy mothers without IDA (hemoglobin ≥110 g/L and serum ferritin >12 μg/L) served as controls. Maternal and fetal inflammatory conditions, infections and neonates with perinatal asphyxia were excluded. Cord blood BDNF concentrations were estimated by enzyme-linked immunosorbent assay. Volumetric analysis of hippocampus (right, left and combined, corrected for total intracranial volume) was done by cranial magnetic resonance imaging on days 3-5 of life. In the study group, 24 mothers had mild (hemoglobin 100.0-109.0 g/L), 24 had moderate (hemoglobin 70.0-99.0 g/L), and 22 had severe (hemoglobin <70.0 g/L) anemia. Both hippocampal volumes and serum BDNF concentrations of neonates born to iron-deficient mothers were significantly reduced compared to controls. A progressive decline in hippocampal volumes and BDNF concentrations was observed with increasing severity of maternal anemia. Pearson correlation showed significant correlations among maternal and cord blood hemoglobin, iron indices, hippocampal volumes and BDNF concentrations. Maternal IDA adversely affects hippocampal morphogenesis and fetal production of BDNF. The degree of affection is proportional to the severity of maternal anemia.

The effect of acute exercise on blood concentrations of brain-derived neurotrophic factor in healthy adults: a meta-analysis.

It has been hypothesized that one mechanism through which physical activity provides benefits to cognition and mood is via increasing brain-derived neurotrophic factor (BDNF) concentrations. Some studies have reported immediate benefits to mood and various cognitive domains after a single session of exercise. This meta-analysis sought to determine the effect of a single exercise session on concentrations of BDNF in peripheral blood, in order to evaluate the potential role of BDNF in mediating the beneficial effects of exercise on brain health. MEDLINE, Embase, PsycINFO, SPORTDiscus, Rehabilitation & Sports Medicine Source, and CINAHL databases were searched for original, peer-reviewed reports of peripheral blood BDNF concentrations before and after acute exercise interventions. Risk of bias within studies was assessed using standardized criteria. Standardized mean differences (SMDs) were generated from random effects models. Risk of publication bias was assessed using a funnel plot and Egger's test. Potential sources of heterogeneity were explored in subgroup analyses. In 55 studies that met inclusion criteria, concentrations of peripheral blood BDNF were higher after exercise (SMD=0.59, 95% CI: 0.46-0.72, P<0.001). In meta-regression analysis, greater duration of exercise was associated with greater increases in BDNF. Subgroup analyses revealed an effect in males but not in females, and a greater BDNF increase in plasma than serum. Acute exercise increased BDNF concentrations in the peripheral blood of healthy adults. This effect was influenced by exercise duration and may be different across genders.

The Effect of Exercise Training on Resting Concentrations of Peripheral Brain-Derived Neurotrophic Factor (BDNF): A Meta-Analysis.

BackgroundThe mechanisms through which physical activity supports healthy brain function remain to be elucidated. One hypothesis suggests that increased brain-derived neurotrophic factor (BDNF) mediates some cognitive and mood benefits. This meta-analysis sought to determine the effect of exercise training on resting concentrations of BDNF in peripheral blood.MethodsMEDLINE, Embase, PsycINFO, SPORTDiscus, Rehabilitation & Sports Medicine Source, and CINAHL databases were searched for original, peer-reviewed reports of peripheral blood BDNF concentrations before and after exercise interventions ≥ 2 weeks. Risk of bias was assessed using standardized criteria. Standardized mean differences (SMDs) were generated from random effects models. Risk of publication bias was assessed using funnel plots and Egger’s test. Potential sources of heterogeneity were explored in subgroup analyses.ResultsIn 29 studies that met inclusion criteria, resting concentrations of peripheral blood BDNF were higher after intervention (SMD = 0.39, 95% CI: 0.17–0.60, p < 0.001). Subgroup analyses suggested a significant effect in aerobic (SMD = 0.66, 95% CI: 0.33–0.99, p < 0.001) but not resistance training (SMD = 0.07, 95% CI: -0.15–0.30, p = 0.52) interventions. No significant difference in effect was observed between males and females, nor in serum vs plasma.ConclusionAerobic but not resistance training interventions increased resting BDNF concentrations in peripheral blood.

Peripheral blood brain-derived neurotrophic factor in bipolar disorder: a comprehensive systematic review and meta-analysis

Peripheral blood brain-derived neurotrophic factor (BDNF) has been proposed as a potential biomarker related to disease activity and neuroprogression in bipolar disorder, speculated to mirror alterations in brain expression of BDNF. The research area is rapidly evolving; however, recent investigations have yielded conflicting results with substantial variation in outcomes, highlighting the need to critically assess the state of current evidence. The aims of the study were to investigate differences in peripheral blood BDNF concentrations between bipolar disorder patients and healthy control subjects and between affective states in bipolar disorder patients, including assessment of the effect of treatment of acute episodes on BDNF levels. A systematic review of English language studies without considering publication status was conducted in PubMed (January 1950-November 2014), Embase (1974-November 2014) and PsycINFO (1806-November 2014), and 35 studies comprising a total of 3798 participants were included in the meta-analysis. The results indicated that crude peripheral blood BDNF levels may be lower in bipolar disorder patients overall (Hedges' g=-0.28, 95% CI: -0.51 to -0.04, P=0.02) and in serum of manic (g=-0.77, 95% CI: -1.36 to -0.18, P=0.01) and depressed (g=-0.87, 95% CI: -1.42 to -0.32, P=0.002) bipolar disorder patients compared with healthy control subjects. No differences in peripheral BDNF levels were observed between affective states overall. Longer illness duration was associated with higher BDNF levels in bipolar disorder patients. Relatively low study quality, substantial unexplained between-study heterogeneity, potential bias in individual studies and indications of publication bias, was observed and studies were overall underpowered. It could thus not be excluded that identified differences between groups were due to factors not related to bipolar disorder. In conclusion, limitations in the evidence base prompt tempered conclusions regarding the role of peripheral BDNF as a biomarker in bipolar disorder and substantially improving the quality of further research is warranted.

Prognostic Significance of Blood Brain-Derived Neurotrophic Factor (BDNF) in the Treatment of Various Functional and Organic Nervous System Diseases with Adaptol

The efficacy of using Adaptol in the complex treatment of patients with autonomic-vascular dystonia following closed craniocerebral trauma was studied. Patient status was evaluated before treatment started and after treatment ended, using clinical and neuropsychological scales, with simultaneous investigation of serum BDNF concentrations. On the background of Adaptol treatment, there was a significant (p < 0.05) increase in the serum BDNF concentration, with showed a significant (p < 0.05) correlation with decreases in the severity of anxiety and improvements in cognitive functions. The effects of the agent were dose-dependent. These results allow Adaptol to be recommended for the treatment of diseases requiring stimulation of neuroplasticity in the CNS.

Bdnf Response To Arms Versus Legs Strength Exercise

Blood neurotrophins like brain-derived neurotrophic factor (BDNF) are considered to be of major importance for mediating the benefits of physical exercise on the brain by the induction of central and peripheral growth factor cascades. Increases of blood BDNF concentrations in humans have been reported after acute intensive endurance exercise, but not after acute moderate endurance exercise. Concerning strength exercise, although basal BDNF level is not altered significantly after strength training, we could suggest that acute intensive strength exercise might also increases BDNF blood concentrations. PURPOSE: For this purpose, we performed an intensive strength protocol, through an isokinetic muscle exercise and analyzed the effect of small (arms) versus large (legs) muscle mass on BDNF blood release. METHODS: Sixteen young, healthy male subjects participated in the study. Knee and elbow muscle performance were determined using a Cybex 6000 isokinetic dynamometer (Ronkonkoma, NY) in two separated days. Five series of ten repetitions during 60°/s were performed after 5 min warm up in a stationary bicycle. Successive series was separated by 40 seconds of rest. RESULTS: BDNF plasma concentrations did not alter significantly after acute intensive strength sessions. No significant differences were observed among arms and legs paradigms both at rest and after exercise. CONCLUSION: Our data demonstrated that acute intense muscle contractions (strength exercise) are not able to altered plasma BDNF, suggesting that the type of exercise is a critical factor to provoke plasma BDNF release. Research supported by CNPq, FAPESP, CAPES, INNT and ClnAPCe (Brazil).

Measurements of brain-derived neurotrophic factor: Methodological aspects and demographical data

Although numerous studies have dealt with changes in blood brain-derived neurotrophic factor (BDNF), methodological issues about BDNF measurements have only been incompletely resolved. We validated BDNF ELISA with respect to accuracy, reproducibility and the effect of storage and repeated freezing cycles on BDNF concentrations. Additionally, the effect of demographic characteristics in healthy subjects on BDNF was verified. Whole blood and serum was collected from 206 healthy subjects and a subgroup was genotyped for BDNF Val66Met polymorphism. The effect of age, gender, BDNF genotype and thrombocyte count on whole blood BDNF was assessed. The BDNF ELISA measurement was accurate, 91.6 ± 3.0%, and showed high reproducibility, whereas inter-assay and intra-subject variations were modest, 8.4 ± 5.2% and 17.5 ± 14.1%, respectively. Storage of whole blood samples at 4 °C significantly decreased BDNF concentration, while repeated freezing cycles and storage at −20 °C was without any effect. Storage at −20 °C of serum, but not whole blood, was associated with a significant decrease in BDNF concentration. Women had significantly higher whole blood BDNF concentrations than men (18.6 ± 1.3 ng/ml versus 16.5 ± 1.4 ng/ml), and showed a right-skewed BDNF concentration distribution. No association between whole blood BDNF concentrations and thrombocyte count, age, or BDNF genotype was found. In conclusion, the BDNF ELISA assay determines whole blood BDNF accurately and with high reproducibility. Female gender is associated with higher whole blood BDNF concentrations whereas age, thrombocyte count and BDNF Val66Met polymorphism were un-associated.