Differences In Serum Brain-derived Neurotrophic Factor Levels Research Articles

Sex-dependent associations of serum BDNF, glycolipid metabolism and cognitive impairments in Parkinson's disease with depression: a comprehensive analysis.

Brain-derived neurotrophic factor (BDNF) and glycolipid metabolism have been implicated in cognitive impairments and depression among Parkinson's disease (PD). However, the role of sex differences in this relationship remains elusive. This study aimed to investigate the potential sex differences in the link between serum BDNF levels, glycolipid metabolism and cognitive performance among depressive PD patients. PD patients comprising 108 individuals with depression and 108 without depression were recruited for this study. Cognitive function was assessed using the Montreal Cognitive Assessment Beijing version (MOCA-BJ). The severity of depressive symptoms was assessed using the Hamilton Depression Rating Scale (HAMD-17), while motor symptoms were evaluated using the Revised Hoehn and Yahr rating scale (H-Y) and the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III). Laboratory testing and enzyme-linked immunosorbent assay (ELISA) are used to measure serum levels of glycolipid metabolism and BDNF. Females showed superior performance in delayed recall (all p < 0.05), male PD patients exhibited higher scores in naming tasks compared to females in non-depression group. There was no sex differences in serum BDNF levels between depression and non-depression groups. Liner regression analysis indicated BDNF as an independent risk factor for language deficits in male PD patients with depression (p < 0.05), while cholesterol (CHOL) emerged as a cognitive influencing factor, particularly in delayed recall among male PD patients with depression (p < 0.05). Our study reveals extensive cognitive impairments in PD patients with depression. Moreover, BDNF and CHOL may contribute to the pathological mechanisms underlying cognitive deficits, particularly in male patients with depression.

Severe depression is associated with decreased levels of serum brain-derived neurotrophic factor in type 2 diabetes patients in Ghana

ABSTRACT Objectives Type 2 diabetes (T2DM) has been associated with several mental disorders including depression. Brain-derived neurotrophic factor (BDNF) has been suggested as a mediator between T2DM and depression. We investigated the association between BDNF and depression in T2DM patients in a primary health facility in Ghana. Methods In a case-control study design, depression was assessed using the Patient’s Health Questionnaire (PHQ-9) in 200 T2DM patients and 160 non-diabetic controls. A structured questionnaire was used to collect data on lifestyle, socio-demography and medical history. Fasting blood samples were collected from each participant to measure plasma lipid profile and serum BDNF levels. Results T2DM patients had higher levels of depression (31.5% vs 10.6, p < 0.001) and lower serum levels of BDNF (22.8 ± 4.6 vs 34.6 ± 10.6, p < 0.001) compared to non-diabetic controls. In non-diabetic controls, those with depression had low levels of serum BDNF compared to their non-depressed counterparts (38.9 ± 10.1 vs 32.3 ± 9.9 ng/ml, p = 0.038), but in T2DM patients, no difference in serum BDNF levels was observed in those with and without depression. Severe depression in T2DM patients [OR (95% CI): 0.81 (0.57–0.97), p = 0.042] and mild depression in non-diabetic controls [0.84 (0.6–0.95), p < 0.001] were associated with reductions in serum BDNF levels. Conclusions In our study sample, T2DM patients had a high burden of depression and low levels of BDNF compared to the non-diabetic controls. T2DM with severe depression and non-diabetic controls with mild depression had significant reduction of serum BDNF levels.

Brain-derived Neurotrophic Factor Level and Gene Polymorphism as Risk Factors for Depression in Patients with type 2 Diabetes Mellitus- A Case-Controlled Study.

Diabetes mellitus and depression are comorbidities that can be caused by each other. Brain-derived neurotrophic factor (BDNF) functions as a neuronal growth factor. It maintains the functional integrity of the nervous system. To study the possible association between BDNF levels and gene polymorphism with depression in patients diagnosed with type 2 diabetes mellitus. The Elisa technique measured BDNF, and rs6265 gene polymorphism was detected using real-time PCR. Depression was assessed utilizing a clinical interview tool designed to establish the diagnosis of depression and differentiate it from other psychiatric diseases. BDNF levels were significantly lower in patients with type 2 diabetes mellitus and symptoms of depression than in patients with type 2 diabetes mellitus and no symptoms of depression (82.6±16.1. Vs 122± 17.47, p˂ 0.001). There was a statistically significant difference in BDNF levels in patients with diabetes among the three genotypes of the BDNF gene (p-value < 0.001). Val/ Val carriers had the highest serum BDNF levels, and Met/ Met carriers had the lowest serum BDNF levels. Subgroup analysis showed statistically significant genotype-related differences in serum BDNF levels among the three subgroups in the Depression group. Val/ Val carriers had the highest serum BDNF levels, and Met/ Met carriers had the lowest serum BDNF levels. BDNF Val66Met polymorphism had no significant association with the presence of depression, yet there was a trend towards significance (p = 0.05) Conclusion: In this pilot, Low levels of BDNF were associated with depression in patients with type 2 diabetes. Carriers of the Met/ Met allele have the lowest serum BDNF levels. Multicenter studies with more participants are required.

The Plasma Neurofilament Light Chain, Brain-Derived Neurotrophic Factor, and Risk of Depression in Chronic Hemodialysis Patients.

Depression is highly prevalent among hemodialysis patients. Understanding the relationship between the plasma neurofilament light chain (NfL) and brain-derived neurotrophic factor (BDNF) may help us to better understand the mechanisms of depression. This study determined their impact, alongside that of other factors, on the risk of depression in hemodialysis patients. The study enrolled 82 patients undergoing chronic hemodialysis. Serum NfL, BDNF, uric acid, urea, potassium, calcium, phosphorus, intact parathyroid hormone, and C-reactive protein (CRP) levels were measured. The patients completed the Beck Depression Inventory (BDI). Blood pressure values, body mass before and after hemodialysis, and weekly duration of hemodialysis in hours were assessed. For 19-month survival analysis, the patients were stratified according to baseline BDI scores. Based on the BDI score, 18.3% of the patients had an increased risk of depression. Lower scores were associated with significantly longer duration of hemodialysis treatment (37.5 (25-57) 24 (14-37) months, p = 0.01). Within the 19-month survival analysis, 31.7% of patients died. The patients with BDI scores above the median had significantly lower survival than those below the median (log-rank test p = 0.02). No significant differences in serum BDNF levels (192.7 [125.2-278.2]; 207.7 [142.8-265.8] pg/mL, p = 0.40), or NfL concentrations (1431.5 [1182.6-1625.7]; 1494.6 [1335.7-1667] kDa, p = 0.52) were found between patients with lower and higher risk of depression. Patients with BDI scores above the median had significantly higher levels of CRP (9.6 [4.4-14]) than those with scores below the median (3.6 [2.2-7.5], p = 0.01). A significant positive correlation was found between the BDI score and serum CRP level (r = 0.38, p = 0.01). A significant negative correlation was observed between the BDI score and URR% value (r = -0.36, p = 0.02). Patients with lower BDI scores had a longer dialysis duration, indicating a potential negative association between depression risk and length of dialysis treatment. Neither serum NfL nor BDNF levels can serve as markers of depression risk in the dialysis population.

Cognitive impairment is associated with BDNF-TrkB signaling mediating synaptic damage and reduction of amino acid neurotransmitters in heart failure.

Heart failure (HF) is often accompanied by cognitive impairment (CI). Brain-derived neurotrophic factor (BDNF) deficiency is closely associated with CI. However, the role and mechanism of BDNF in HF with CI is still not fully understood. Here, the case-control study was designed including 25 HF without CI patients (HF-NCI) and 50 HF with CI patients (HF-CI) to investigate the predictive value of BDNF in HF-CI while animal and cell experiments were used for mechanism research. Results found that BDNF levels in serum neuronal-derived exosomes were downregulated in HF-CI patients. There was no significant difference in serum BDNF levels among the two groups. HF rats showed obvious impairment in learning and memory; also, they had reduced thickness and length of postsynaptic density (PSD) and increased synaptic cleft width. Expression of BDNF, TrkB, PSD95, and VGLUT1 was significantly decreased in HF rats brain. In addition, compared with sham rats, amino acids were significantly reduced with no changes in the acetylcholine and monoamine neurotransmitters. Further examination showed that the number of synaptic bifurcations and the expression of BDNF, TrkB, PSD95, and VGLUT1 were all decreased in the neurons that interfered with BDNF-siRNA compared with those in the negative control neurons. Together, our results demonstrated that neuronal-derived exosomal BDNF act as effective biomarkers for prediction of HF-CI. The decrease of BDNF in the brain triggers synaptic structural damage and a decline in amino acid neurotransmitters via the BDNF-TrkB-PSD95/VGLUT1 pathway. This discovery unveils a novel pathological mechanism underlying cognitive impairment following heart failure.

Serum brain-derived neurotrophic factor and glial cell-derived neurotrophic factor in patients with first-episode depression at different ages

Objectives We investigated the differences in serum brain-derived neurotrophic factor (BDNF) and glial cell line–derived neurotrophic factor (GDNF) levels and clinical symptoms with first-episode depression at different ages. Methods Ninety patients (15–60 years old) diagnosed with first-episode depression were enrolled as the study group, and they were divided into early-onset, adult and late-onset groups. The age-matched control groups were healthy volunteers. Serum BDNF and GDNF concentrations were determined by enzyme-linked immunosorbent assay (ELISA). GraphPad Prism 9 was used for t tests, one-way ANOVAs, chi-square tests, and correlation analyses. p < 0.05 indicated significant differences. Results Serum BDNF and GDNF levels were lower in the whole study group and the three subgroups than in the healthy groups. Illness severity, anxiety and education were higher in the early-onset than late-onset patients. Serum BDNF levels were lower in the adult than late-onset patients. Serum BDNF levels were negatively correlated with patient CGI-SI scores. After the LSD test for multiple comparisons, the results were also significant. Conclusions Low serum BDNF and GDNF levels may be involved in the pathophysiology of first-episode depression, and there were differences in serum BDNF levels at different ages, verifying that serum BDNF and GDNF could serve as potential biomarkers of depression. KEY POINTS Depression is often conceptualised as a systemic illness with different biological mechanisms, but satisfactory explanations have not been provided thus far. The aim of our study was to investigate differences in serum BDNF and GDNF levels and their relationships with clinical symptoms in patients with first-episode depression at different ages. The potential of the neurotrophic factor hypothesis to advance the diagnosis and treatment of depression will be a very exciting new strategy for future research.

Comparison of brain-derived neurotrophic factor (BDNF) serum level in inflammatory and non-inflammatory acne vulgaris

Background: Acne vulgaris is a chronic and self-limiting inflammation disorder of the pilosebaceous unit, generally manifested in adolescents with polymorphic lesions, such as comedones, papules, nodules, and cyst. Brain-derived neurotrophic factor (BDNF) is a member of neurotrophins that can be downregulated because of stress. It is suspected that a lower BDNF level is induced inflammatory process, although its relationship with acne vulgaris has not been widely studied. This study compared BDNF serum levels in the inflammatory and non-inflammatory type of acne vulgaris.Methods: This is analytical observational research with a cross-sectional design that involved 31 acne vulgaris patients with inflammatory lesions and 31 acne vulgaris patients with non-inflammatory lesions. Each subject was interviewed and going through dermatology examinations, followed by blood sampling to assessed their BDNF serum levels through the ELISA test. The collected data were analyzed statistically using an independent T-test. P&lt;0.05 was significant.Result: The mean BDNF serum levels in acne vulgaris patients were 32,53±6,32 ng/ml. In subjects with inflammatory-type lesions, the mean BDNF level is 27,55±3,31 ng/ml. While, in the non-inflammatory type lesions group, the mean BDNF is 37,51±4,37 ng/ml. The BDNF serum level is significantly lower in inflammatory-type subjects than in non-inflammatory type (p &lt; 0,001).Conclusion: There was a significant difference in serum BDNF levels between the inflammatory and non-inflammatory type acne groups.

Changes in Cortisol but Not in Brain-Derived Neurotrophic Factor Modulate the Association Between Sleep Disturbances and Major Depression.

Sleep disturbance is a symptom consistently found in major depression and is associated with a longer course of illness, reduced response to treatment, increased risk of relapse and recurrence. Chronic insomnia has been associated with changes in cortisol and serum brain-derived neurotrophic factor (BDNF) levels, which in turn are also changed in major depression. Here, we evaluated the relationship between sleep quality, salivary cortisol awakening response (CAR), and serum BDNF levels in patients with sleep disturbance and treatment-resistant major depression (n = 18), and in a control group of healthy subjects with good (n = 21) and poor (n = 18) sleep quality. We observed that the patients had the lowest CAR and sleep duration of all three groups and a higher latency to sleep than the healthy volunteers with a good sleep profile. Besides, low CAR was correlated with more severe depressive symptoms and worse sleep quality. There was no difference in serum BDNF levels between groups with distinct sleep quality. Taken together, our results showed a relationship between changes in CAR and in sleep quality in patients with treatment-resistant depression, which were correlated with the severity of disease, suggesting that cortisol could be a physiological link between sleep disturbance and major depression.

Decreased Serum Brain-Derived Neurotrophic Factor (BDNF) Levels in Patients with Alzheimer's Disease (AD): A Systematic Review and Meta-Analysis.

Findings from previous studies reporting the levels of serum brain-derived neurotrophic factor (BDNF) in patients with Alzheimer’s disease (AD) and individuals with mild cognitive impairment (MCI) have been conflicting. Hence, we performed a meta-analysis to examine the aggregate levels of serum BDNF in patients with AD and individuals with MCI, in comparison with healthy controls. Fifteen studies were included for the comparison between AD and healthy control (HC) (n = 2067). Serum BDNF levels were significantly lower in patients with AD (SMD: −0.282; 95% confidence interval [CI]: −0.535 to −0.028; significant heterogeneity: I2 = 83.962). Meta-regression identified age (p < 0.001) and MMSE scores (p < 0.001) to be the significant moderators that could explain the heterogeneity in findings in these studies. Additionally, there were no significant differences in serum BDNF levels between patients with AD and MCI (eight studies, n = 906) and between MCI and HC (nine studies, n = 5090). In all, patients with AD, but not MCI, have significantly lower serum BDNF levels compared to healthy controls. This meta-analysis confirmed the direction of change in serum BDNF levels in dementia. This finding suggests that a significant change in peripheral BDNF levels can only be detected at the late stage of the dementia spectrum. Molecular mechanisms, implications on interventional trials, and future directions for studies examining BDNF in dementia were discussed.

Brain derived neurotrophic factor in newly diagnosed diabetes and prediabetes

Brain derived neurotrophic factor (BDNF) is thought to play an important role in glucose metabolism, but the exact mechanism has not been elucidated. The aim was to assess differences in serum BDNF levels across individuals with varying levels of glucose tolerance, and the association of serum BDNF levels with genetic variants and DNA methylation. Participants were selected from an ongoing population-based cohort study in rural China. In a randomly selected subsample of healthy participants (n = 33 males, n = 52 female), we assessed serum BDNF and in n = 50 of these, also DNA methylation. In a second subsample (all women; n = 28 with diabetes, n = 104 with prediabetes, and n = 105 age- and body mass index (BMI)-matched controls), we assessed serum BDNF and genetic variants. In a third subsample (all with diabetes; n = 7 normal BMI + low insulin level, n = 9 normal BMI + high insulin level, n = 9 obese + high insulin level), we assessed DNA methylation. Compared to age- and BMI-matched controls (24.71 (IQR, 20.44, 29.80) ng/ml), serum BDNF was higher in participants with prediabetes (27.38 (IQR, 20.64, 34.29) ng/ml), but lower in those with diabetes (23.40 (IQR, 18.12, 30.34) ng/ml) (P < 0.05). Two genetic variants near BDNF (rs4074134 and rs6265) were confirmed to be associated with BMI. BDNF CpG-6 methylation was positively associated with waist-to-hip ratio (P < 0.05). Furthermore, hyper-methylation in this site was found in participants with diabetes and high fasting insulin levels compared to those with diabetes and low fasting insulin levels, regardless of BMI status (P < 0.001 and P = 0.001, respectively). Observed differences in serum BDNF levels, genetic variants, and DNA methylation patterns across different glucose metabolic state suggest that BDNF may be involved in the pathophysiological process of insulin resistance and type 2 diabetes.

Effect of intraoperative application of ketamine on postoperative depressed mood in patients undergoing elective orthopedic surgery.

A depressed mood frequently occurs in perioperative patients, negatively impacting patient recovery. Recent studies suggested that ketamine has a rapid, obvious, and persistent antidepressant effect. The purpose of this study was to investigate the impact of intraoperative application of ketamine on postoperative depressive mood in patients undergoing elective orthopedic surgery. This was a randomized, double-blind, controlled study. A total of 120 patients (ASA grade I-II) undergoing elective orthopedic surgery were divided randomly into a ketamine group (group K) and a control group (group C). In the K group, 0.5 mg/kg (0.05 ml/kg) ketamine was given at induction of anesthesia, followed by 0.25 mg/kg/h (0.025 ml/kg/h) continuous infusion for 30 min. In the C group, 0.05 ml/kg 0.9 % saline was used at induction of anesthesia, followed by 0.025 ml/kg/h continuous infusion of saline for 30 min. PHQ-9 score was recorded preoperatively (1 day before surgery) and postoperatively (on day 1 and day 5 following surgery). Blood at these time points was drawn for serum brain-derived neurotrophic factor (BDNF) level analysis. Intraoperative blood loss, surgery time, postoperative visual analog scale pain scores and perioperative complications were also recorded. There were no differences in age, sex, surgery time, blood loss, and preoperative PHQ-9 scores between the two groups (P > 0.05). There were no differences in PHQ-9 scores preoperatively and postoperatively for the C group (P > 0.05); however, the PHQ-9 postoperative scores were lower than the preoperative PHQ-9 scores in the K group (P < 0.01). Postoperative PHQ-9 scores of K group were lower than those of C group (P < 0.05). There were no differences in serum BDNF levels in C group pre- to postoperatively (P > 0.05). Compared with the preoperative BDNF levels of K group, postoperative BDNF levels in K group increased significantly (P < 0.01). An inverse correlation between PHQ-9 score and serum BDNF level was shown. Intraoperative application of ketamine was associated with improved scores for depressed mood and increased serum BDNF levels in patients undergoing elective orthopedic surgery.

Increased serum brain-derived neurotrophic factor levels during opiate withdrawal

Brain-derived neurotrophic factor (BDNF) has been implicated in the pathophysiology of opiate addiction. Both increased and decreased serum BDNF levels have been reported in heroin addicts. Moreover, the role of BDNF in heroin-dependent patients during withdrawal has not been studied. This study aimed to explore the differences in serum BDNF levels of heroin addicts and healthy controls, and investigate the changes of serum BDNF levels in heroin addicts at baseline and at one month after heroin cessation. Seventy-two heroin-dependent patients and ninety age- and gender-matched healthy controls were enrolled in this study. We measured serum BDNF levels at baseline (both heroin addicts and healthy controls) and one month after heroin cessation (heroin addicts only). A total of 37 (51.4%) heroin addicts completed the one-month study. We found that baseline serum BDNF levels were significantly higher in heroin addicts compared to controls (F=36.5, p=0.001). There was no difference in serum BDNF levels among heroin addicts at baseline and one month after heroin cessation (F=1.101, p=0.301). These results indicate that BDNF may play a critical role in the course of opiate addiction and withdrawal.

Serum BDNF Levels in Relation to Illness Severity, Suicide Attempts, and Central Serotonin Activity in Patients with Major Depressive Disorder: A Pilot Study

The aim of this study was to test the hypothesis that serum levels of brain-derived neurotrophic factor (BDNF) are correlated with the loudness dependence of auditory evoked potentials (LDAEP). The question of whether there is a difference in BDNF levels between depressive patients according to their illness severity, history of suicide attempts, and central serotonin activity was also addressed. A sample of 51 patients who met the criteria for major depressive disorder following diagnosis using axis I of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders – text revision comprised the study subjects. The patients were stratified into two subgroups based on their illness severity, history of suicide attempts, and their LDAEP values. The LDAEP was evaluated by measuring the auditory event-related potentials, and serum BDNF was measured using blood sampling before beginning medication with serotonergic agents. There was no difference in serum BDNF levels between the two patient subgroups. The subgroup with moderate-to-severe depression (n = 16) was reanalyzed after stratifying it into two subgroups according to LDAEP and BDNF values (dichotomized at the medians into low and high). The high-LDAEP subgroup had higher serum BDNF levels and total Barratt Impulsiveness Scale score than the low-LDAEP subgroup (p = 0.03 and 0.036, respectively). Serum BDNF levels were positively correlated with LDAEP and total Beck Hopelessness Scale (BHS) score (r = 0.56, p = 0.025, and r = 0.59, p = 0.016, respectively). The high-BDNF subgroup had a higher LDAEP and total BHS score than the low-BDNF subgroup (p = 0.046 and p = 0.011, respectively). This is the first study to demonstrate a relationship between the BDNF level and LDAEP in Asian depressive patients. Intriguingly, the high-BDNF subgroup (divided according to illness severity) exhibited a more severe psychopathology on some psychometric rating scales, a finding that conflicts with previous results.

BDNF: an indicator of insomnia?

BDNF: an indicator of insomnia?

P-179 - Brain-derived neurotrophic factor as a biomarker of clinical response in bipolar disorder: 16 week follow-up study

Despite therapeutic advances, we still have difficulties in predicting response to treatment in bipolar disorder (BD). Brain-Derived Neurotrophic Factor (BDNF) has been put forward as a potential peripheral marker of treatment response. To prospectively study the relation between clinical response to treatment and serum BDNF levels. To investigate a) a possible association between serum BDNF levels and clinical response along 16 week follow-up and b) the role of val66met polymorphism in clinical response in a sample of drug-free patients with BD going through a mood episode. This is a naturalistic, open-label prospective nested case control study matched for age, gender and ethnicity. Patients were 18 years or older, required BD diagnosis, undergoing a current manic, mixed or depressive episode and be off-medication for at least 2 weeks. Clinical assessment and blood withdrawn were conducted along follow-up. At the end of the study, patients were classified according to clinical response. 25 of 36 (69.4%) of the patients were female and the mean age was 37.8 (SD 11.8) years old. Baseline serum BDNF levels did not show any difference between patients and controls ( p = 0.075).There was a significant negative correlation between differences in serum BDNF levels and in CGI score along follow-up ( r = −.372, p = 0.028). Serum BDNF levels were significant higher in responders compared to non-responders at week 4, 8 and 16 ( p = 0.026, p = 0.009, p = 0.001 respectively). Val66met polymorphism did not seem to interfere in clinical response. Changes in serum BDNF levels may help in monitoring treatment response.

Effects of Electroconvulsive Therapy and Repetitive Transcranial Magnetic Stimulation on Serum Brain-Derived Neurotrophic Factor Levels in Patients with Depression

Objective: Brain-derived neurotrophic factor (BDNF) levels are decreased in individuals with depression and increase following antidepressant treatment. The objective of this study is to compare pre- and post-treatment serum BDNF levels in patients with drug-resistant major depressive disorder (MDD) who received either electroconvulsive therapy (ECT) or repetitive transcranial magnetic stimulation (rTMS). It is hypothesized that non-pharmacological treatments also increase serum BDNF levels. Methods: This was a prospective, single-blind study comparing pre- and post-treatment serum BDNF levels of 29 patients with drug-resistant MDD who received ECT or rTMS treatment. Serum BDNF levels were measured 1 week prior to and 1 week after treatment using the sandwich ELISA technique. Depression severity was measured 1 week before and 1 week after treatment using the Hamilton Depression Rating Scale. Two-sided normal distribution paired t-test analysis was used to compare pre- and post-treatment BDNF concentration and illness severity. Bivariate correlations using Pearson’s coefficient assessed the relationship between post-treatment BDNF levels and post-treatment depression severity. Results: There was no significant difference in serum BDNF levels before and after ECT, although concentrations tended to increase from a baseline mean of 9.95–12.29 ng/ml after treatment (p = 0.137). Treatment with rTMS did not significantly alter BDNF concentrations (p = 0.282). Depression severity significantly decreased following both ECT (p = 0.003) and rTMS (p < 0.001). Post-treatment BDNF concentration was not significantly correlated with post-treatment depression severity in patients who received either ECT (r = −0.133, p = 0.697) or rTMS (r = 0.374, p = 0.126). It is important to note that these results are based on the small number of patients included in this study. Conclusion: This study suggests that ECT and rTMS may not exert their clinical effects by altering serum BDNF levels in patients with drug-resistant MDD. Serum BDNF concentration may not be a biomarker of ECT or rTMS treatment response.

Associations of serum brain-derived neurotrophic factor with cognitive impairments and negative symptoms in schizophrenia

Brain-derived neurotrophic factor (BDNF) may be involved in the pathophysiology of schizophrenia. The aim of this study was to examine the associations of serum BDNF levels with the cognition and clinical characteristics in patients with schizophrenia. Sixty-three patients with schizophrenia and 52 age- and sex-matched healthy controls were examined with neuropsychological tests. Serum BDNF levels were determined by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in serum BDNF levels between normal controls and patients with schizophrenia. Serum BDNF levels of normal controls showed negative correlations with verbal working memory, but this was not the case with schizophrenic patients. Meanwhile, serum BDNF levels of schizophrenic patients showed positive correlations with the scores of the Scale for the Assessment of Negative Symptoms (SANS) and the Information subtest scores of Wechsler Adult Intelligence Scale Revised (WAIS-R). Serum BDNF levels are related with the impairment of verbal working memory and negative symptoms in patients with schizophrenia.

Brain-Derived Neurotrophic Factor as a Biomarker in Primary Open-Angle Glaucoma

To introduce a novel biomarker for screening of primary open-angle glaucoma (POAG) by detecting and measuring brain-derived neurotrophic factor (BDNF) in the serum of normal subjects and patients with early stage of glaucoma. Twenty-five glaucoma patients as the case group and 25 age- and sex-matched normal persons as the control group were tested. The control group comprised 19 men and 6 women, with the mean age of 59.32 ± 11.8 years and without any apparent ocular or systemic diseases. The case group comprised 20 men and 5 women, with the mean age of 59.64 ± 11.56 years, who were assessed by routinely performed clinical and paraclinical investigations. BDNF levels in serum were determined by enzyme-linked immunosorbent assay using monoclonal antibodies specific for BDNF. The mean of BDNF levels in the serum was 27.16 ± 5.53 ng/mL in the control subjects and 18.42 ± 4.05 ng/mL in the subjects with the early stage glaucoma. A statistically significant difference was evident between the two groups (p < 0.05). We found no significant differences in serum BDNF levels according to the subjects' age, gender, duration of the glaucoma, mean intraocular pressure, and blood pressure (p > 0.05). Glaucoma patients who had lower serum BDNF concentration had disclosed a significant negative correlation with pattern standard deviations. We conclude that BDNF in the serum might be a useful biochemical marker for early detection of POAG. We also propose that this might be a reliable, time efficient, and cost-effective method for diagnosis, screening, and assessing the progression of POAG. However, more studies and trials are needed to investigate these factors in greater detail.

Differential Patterns of Serum Brain-Derived Neurotrophic Factor Levels in Alcoholic Patients With and Without Delirium Tremens During Acute Withdrawal

Brain-derived neurotrophic factor (BDNF) is associated with alcohol addiction and withdrawal-related neurotoxicity. Delirium tremens (DT) is the most serious complication of alcohol withdrawal syndrome (AWS). In this study, we explored the differences in serum BDNF levels, measured at baseline and 1 week after alcohol withdrawal among alcoholic patients with and without DT. Sixty-five inpatients, fulfilling the DSM-IV criteria of alcohol dependence and admitted for alcohol detoxification, as well as 39 healthy control subjects were enrolled. The alcoholic patients were divided by the appearance of DTs into the DT group (n = 25) and non-DT group (n = 40). We collected blood samples of the patient groups on the first and seventh days of alcohol withdrawal and measured serum BDNF levels by sandwich enzyme-linked immunosorbent assay. Serum BDNF levels differed significantly among the three groups: (i) control group 14.8 ± 4.7 ng/ml; (ii) non-DT group 12.3 ± 3.3 ng/ml; (iii) DT group 6.2 ± 2.6 ng/ml (p < 0.001). One week after alcohol withdrawal, the BDNF levels increased significantly for both alcoholic groups. While non-DT group had comparable BDNF levels (13.4 ± 3.5 ng/ml) with controls, the DT group still exhibited lower levels (8.9 ± 4.4 ng/ml). This study suggests chronic drinking leads to a reduction in BDNF levels, and patients with more deficient BDNF expression are vulnerable to the development of DTs. Additionally, BDNF levels elevated after prompt alcohol detoxification treatment. These findings indicate that BDNF could involve modifying the phenotypes of AWS as well as the pertinent neuroadaptive processes of alcohol dependence.

Influence of exercise on serum brain-derived neurotrophic factor concentrations in healthy human subjects

The effect of short-term exercise (15 min step-exercise) on serum brain-derived neurotrophic factor (BDNF) levels was evaluated in healthy human subjects. Results showed a short-term, significant increase in serum BDNF levels after exercise. Intra-individual differences in serum BDNF levels were remarkably small on the rest day and also when compared to rest values on the day of the exercise test. Inter-individual differences, on the other hand, were larger by comparison. The result of this study supports the need for larger sample size in studies on BDNF changes in psychiatric disorders or psychiatric drug effects.