Serum brain-derived neurotrophic factor concentrations in lean and overweight children and adolescents

Effect of high fat diet on maternal behavior, brain-derived neurotrophic factor and neural stem cell proliferation in mice expressing human placental lactogen during pregnancy

Maternal obesity is a serious health concern because it increases risks of neurological disorders, including anxiety and peripartum depression. In mice, a high fat diet (HFD) in pregnancy can negatively affect placental structure and function as well as maternal behavior reflected by impaired nest building and pup-retrieval. In humans, maternal obesity in pregnancy is associated with reduced placental lactogen (PL) gene expression, which has been linked to a higher risk of depression. PL acting predominantly through the prolactin receptor maintains energy homeostasis and is a marker of placenta villous trophoblast differentiation during pregnancy. Impaired neurogenesis and low serum levels of brain-derived neurotrophic factor (BDNF) have also been implicated in depression. Augmented neurogenesis in brain during pregnancy was reported in the subventricular zone (SVZ) of mice at gestation day 7 and linked to increased prolactin receptor signaling. Here, we used transgenic CD-1 mice that express human (h) PL during pregnancy to investigate whether the negative effects of diet on maternal behavior are mitigated in these (CD-1[hGH/PL]) mice. Specifically, we examined the effect of a HFD on nest building prepartum and pup retrieval postpartum, as well as on brain BDNF levels and neurogenesis. In contrast to wild-type CD-1[WT]mice, CD-1[hGH/PL] mice displayed significantly less anxiety-like behavior, and showed no impairment in prepartum nest building or postpartum pup-retrieval when fed a HFD. Furthermore, the HFD decreased prepartum and increased postpartum BDNF levels in CD-1[WT] but not CD-1[hGH/PL] mice. Finally, neurogenesis in the SVZ as well as phosphorylated mitogen-activated protein kinase, indicative of lactogenic signaling, appeared unaffected by pregnancy and diet at gestation day 7 in CD-1[hGH/PL] mice. These observations indicate that CD-1[hGH/PL] mice are resistant to the negative effects of HFD reported for CD-1[WT] mice, including effects on maternal behaviors and BDNF levels, and potentially, neurogenesis. This difference probably reflects a direct or indirect effect of the products of the hGH/PL transgene.

The Association between Brain-Derived Neurotrophic Factor (BDNF) Protein Level and Body Mass Index

Background and Objectives: Obesity is a major health concern worldwide. Many studies emphasize the important role of brain-derived neurotrophic factor (BDNF) in regulating appetite and body weight. We aimed to investigate the association between BDNF protein serum levels and body mass index (BMI). Materials and Methods: We conducted a cross-sectional study among 108 healthy adult participants divided into six categories depending on their body mass index (BMI). The ages of the participants ranged between 21 to 45 years. The BDNF serum level was measured using the enzyme-linked immunosorbent assay (ELISA) technique. Results: A Kruskal−Wallis test showed a significant difference in BDNF between the different BMI categories, χ2(2) = 24.201, p < 0.001. Our data also showed that BDNF levels were significantly lower in people with obesity classes II and III than those of normal weight (p < 0.05). The Spearman rank correlation test was statistically significant with negative correlations between the BMI and BDNF (r) = −0.478, (p < 0.01). Moreover, we observed a negative dose-dependent relationship pattern between BMI categories and the levels of circulating BDNF protein. Conclusions: In this study, our data support the hypothesis that low serum levels of BDNF are associated with high BMI and obesity in Saudi adults.

Relationship between Physical Fitness and Academic Performance in University Students

Several studies involving students have been developed with the objective to analyse the influence of different factors on academic performance. Nevertheless, all these studies were focused on stress and sympathetic modulation response instead of contemplating other physiological parameters that may affect academic performance. The aim of the present study was to analyse body composition, cardiovascular, sleep habits and physical activity factors related to the academic performance of university students. Two hundred and sixty-one students with bachelor's degrees in physical activity and sports science participated in the present study (age: 22.49 ± 3.84 years; weight: 73.94 ± 11.4 kg; height: 176.28 ± 7.68 cm; 87.7% males). Participants were divided into two groups according to their academic performance: low academic performance group (LAPG) and high academic performance group (HAPG). Body composition, blood pressure, physical activity and sleep habits were measured, and maximum oxygen uptake was estimated by the Cooper's 12 min run test. The results show that students with a high academic performance presented a higher VO₂ max than the LAPG (LAPG = 40.32 ± 6.07; HAPG = 47.91 ± 6.89 mL/kg/min; p < 0.001), as well as lower diastolic blood pressure (LAPG = 72.44 ± 14.27; HAPG = 67.48 ± 13.50 mmHg; p < 0.01) and insomnia levels caused by breathing problems (LAPG = 0.37 ± 0.8; HAPG = 0.13 ± 0.42 a.u.; p = 0.046). Therefore, we found a relevant association between academic performance and VO₂ max, diastolic blood pressure, and insomnia caused by breathing problems. These results highlight the importance of applying different programmes that may improve these factors, especially those related to physical activity and sleep habits in order to improve academic achievement.

Association of plasma brain-derived neurotrophic factor levels and frailty in community-dwelling older adults

Brain-derived neurotrophic factor (BDNF), an exercise-induced neurotrophin, is an important factor in memory consolidation and cognitive function. This study evaluates the association between plasma BDNF levels and frailty in community-dwelling older adults. Plasma BDNF levels were analyzed in a total of 302 individuals aged 70-84 years from the Korean Frailty and Aging Cohort Study. There were 30 (9.9%) participants with frailty. They were older and had a higher prevalence of dementia and depression than those without frailty. There were no differences in the proportion of male sex between the frail and non-frail groups. Plasma BDNF levels were significantly lower in participants with frailty than in those without frailty. The presence of frailty was significantly associated with plasma BDNF levels (odds ratio 0.508, 95% confidence interval 0.304-0.849) as well as age, hemoglobin, and the presence of dementia, and depression. After adjustment for confounding factors, the significant association between plasma BDNF and frailty was maintained (0.495, 0.281-0.874). This association remained consistent after exclusion of individuals with dementia, depression, stroke, diabetes, and osteoporosis. Plasma BDNF levels were significantly associated with frailty in community-dwelling older adults. Our study may suggest the possible role of BDNF as a novel biomarker of frailty.

Increased serum levels of brain-derived neurotrophic factor following wheelchair half marathon race in individuals with spinal cord injury

Objective: Brain-derived neurotrophic factor (BDNF) has beneficial effects on metabolism as well as the peripheral and central nervous systems. The aim of this study was to assess the response of serum BDNF concentration ([BDNF]s) to wheelchair half marathon race in individuals with spinal cord injury (SCI).Design: Prospective observational study.Setting: The 34th Oita International Wheelchair Marathon Race in Japan.Participants: Nine cervical SCIs (CSCI) and 8 thoracic and lumber SCIs (LSCI) male athletes. Interventions: Wheelchair half-Marathon Race.Outcome measures: [BDNF]s, plasma concentrations of adrenaline ([Ad]p), noradrenaline ([Nor]p), and cortisol ([Cor]p), hematocrit, and platelet count were measured the day before, immediately after, and an hour after the race.Results: [BDNF]s increased significantly immediately after the race in both groups (CSCI; P = 0.0055, LSCI; P = 0.0312) but returned to the baseline levels at one hour after the race. However, [BDNF]s immediately and one hour after the race were significantly higher in LSCI than in CSCI (immediately after the race; P = 0.0037, 1 h after the race; P = 0.0206). Hematocrit and platelet count remained unchanged throughout the study. In LSCI, [Ad]p, [Nor]p and [Cor]p increased significantly immediately after and one hour after the race, compared with the baseline values (P < 0.05). On the other hand, these variables remained unchanged throughout the study in the CSCI.Conclusions: [BDNF]_s increased significantly from the baseline in both LCSI and CSCI but was higher in LSCI than in CSCI immediately after and one hour after the race.

Exercise-induced increase in blood-based brain-derived neurotrophic factor (BDNF) in people with multiple sclerosis: A systematic review and meta-analysis of exercise intervention trials

Background

Exercise training may affect the blood levels of brain-derived neurotrophic factor (BDNF), but meta-analyses have not yet been performed comparing pre- and post-intervention BDNF concentrations in patients with multiple sclerosis (PwMS).

Objective

To perform a meta-analysis to study the influence of exercise on BDNF levels and define components that modulate them across clinical trials of exercise training in adults living with multiple sclerosis (MS).

Method

Five databases (PubMed, EMBASE, Cochrane Library, PEDro database, CINAHL) were searched up to June 2021. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, we included 13 articles in the meta-analysis, including 271 subjects. To investigate sources of heterogeneity, subgroup analysis, meta-regression, and sensitivity analysis were conducted. We performed the meta-analysis to compare pre- and post-exercise peripheral levels of BDNF in PwMS.

Results

Post-exercise concentrations of serum BDNF were significantly higher than pre-intervention levels (Standardized Mean Difference (SMD): 0.33, 95% CI: [0.04; 0.61], p-value = 0.02). Meta-regression indicated that the quality of the included studies based on the PEDro assessment tool might be a source of heterogeneity, while no significant effect was found for chronological age and disease severity according to the expanded disability status scale.

Conclusion

This systematic review and meta-analysis shows that physical activity increases peripheral levels of BDNF in PwMS. More research on the effect of different modes of exercise on BDNF levels in PwMS is warranted.

Negative Correlation between Serum Brain-derived Neurotrophic Factor Levels and Obesity Predictor Markers and Inflammation Levels in Females with Obesity

BACKGROUND: Obesity has been widely associated with structural and functional changes in the brain, whereas inflammation is one of the potential mechanisms involved in these changes. OBJECTIVE: This study aims to prove the relationship between serum brain-derived neurotrophic factor (BDNF) levels and obesity predictor markers (body mass index and waist to hip ratio) and inflammation (interleukin-6 and Tumor Necrosis Factor-alpha) levels in females with obesity. METHODS: This study used a cross-sectional study method using 33 females with obesity aged 19-23 years, body mass index (BMI) > 27.5 kg/m2, normal blood pressure, normal resting heart rate (RHR), normal hemoglobin (Hb), and fasting blood glucose (FBG) ≤ 100 mg/dL. The examination of serum BDNF, IL-6, and TNF-α levels using the Enzyme-Linked Immunosorbent Assay (ELISA) method. The data were analyzed using Pearson product-moment test with a significant levels p<0.05. RESULTS: The results indicated that there is a negative correlation between serum BDNF levels and BMI (r = –0.759; p<0.001), WHR (r = –0.675; p<0.001), IL-6 levels (r = –0.530; p<0.001) and TNF-α levels (r = –0.561; p<0.001). CONCLUSION: Based on the results of the study, there is a negative correlation between serum BDNF levels and BMI, waist to hip ratio, and inflammation (interleukin-6 and Tumor Necrosis Factor-alpha) levels in females with obesity. Further studies are needed to confirm the present findings.

Current Methodological Pitfalls and Caveats in the Assessment of Exercise-Induced Changes in Peripheral Brain-Derived Neurotrophic Factor: How Result Reproducibility Can Be Improved

Neural mechanisms, such as enhanced neuroplasticity within the motor system, underpin exercise-induced motor improvements. Being a key mediator of motor plasticity, brain-derived neurotrophic factor (BDNF) is likely to play an important role in mediating exercise positive effects on motor function. Difficulties in assessing brain BDNF levels in humans have drawn attention to quantification of blood BDNF and raise the question of whether peripheral BDNF contributes to exercise-related motor improvements. Methodological and non-methodological factors influence measurements of blood BDNF introducing a substantial variability that complicates result interpretation and leads to inconsistencies among studies. Here, we discuss methodology-related issues and approaches emerging from current findings to reduce variability and increase result reproducibility.

The Relationship between Overweight/Obesity and Executive Control in College Students: The Mediating Effect of BDNF and 5-HT

The main aim of this study was to explore the association between overweight/obesity and executive control (EC) in young adults, and to further analyze the mediating effect of brain-derived neurotrophic factor (BDNF) and serotonin (5-hydroxytryptamine (5-HT)) on the relationship between overweight/obesity and EC. A total of 449 college students aged between 18 and 20 years were recruited for the study between March and December 2019. Their height and weight were then measured professionally. Subsequently, body mass index (BMI) was calculated as weight (kg) divided by the square of height (m). The EC of the participants was then estimated using the Flanker task, while their serum BDNF levels and 5-HT levels were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Finally, the multiple intermediary models in SPSS were used to analyze the mediating effect of 5-HT and BDNF between overweight/obesity and EC. The result show that the overweight/obesity of college students was positively correlated with the response of EC (p ≤ 0.005). However, it was negatively correlated with BDNF (p ≤ 0.05) and 5-HT (p ≤ 0.05). Moreover, BDNF (p ≤ 0.001) and 5-HT (p ≤ 0.001) were negatively correlated with the response of EC. The BDNF level played a partial mediating role between overweight/obesity and EC that accounted for 7.30% of the total effect value. Similarly, the 5-HT of college students played a partial mediating role between overweight/obesity and EC that accounted for 8.76% of the total effect value. Gender and age had no regulatory effect on the relationship between overweight/obesity, BDNF, 5-HT, and EC. This study provides the evidence that 5-HT and BDNF mediated the association between overweight/obesity and executive control. It is indicated that 5-HT and BDNF might be the biological pathways underpinning the link between overweight/obesity and executive control.

Hippocampal neural cell loss in high-fat diet-induced obese rats-exploring the protein networks, ultrastructure, biochemical and bioinformatical markers

OBJECTIVE

Obesity, which has become one of the main health problems, results from irregular and unhealthy nutrition. In particular, an increase in the intake of high-fat foods leads to obesity and associated disorders. It is noteworthy to specify that obese individuals have memory problems. This study aims to examine the effects of high-fat diet on hippocampus, with stereological, histopathological methods and STRING bioinformatic tool.

METHODS

Female Adult Sprague Dawley rats (n = 20) were equally divided into control (CONT) and high-fat diet (HFD) groups. The control group was given standard rat pellet feed, while the high-fat diet group was fed with a 40 % fat content for 2 months. Following the feeding program, rats were sacrificed. The collected blood samples were analyzed biochemically to determine the level of oxidative stress while performing a stereological and histopathological examination of the brain tissues. Functional protein-protein networks for BDNF, C-Fos, CAT, LPO, SOD and MPO by gene ontology (GO) enrichment analysis were evaluated.

FINDINGS

The number of neurons decreased in the HFD group compared to the CONT group. Damage to the histological structure of the hippocampus region; such as degenerate neurons, damaged mitochondria and extended cisterns of the endoplasmic reticulum was observed. Although C-Fos level and oxidative stress parameters increased in HFD group, BDNF level decreased. While BDNF and C-Fos were observed in pathways related to neuron death, oxidative stress and memory, BDNF was pronounced in the mitochondria, and C-Fos in the endoplasmic reticulum.

DISCUSSION

This study shows that changes in both BDNF and C-Fos levels in obesity due to high-fat diet increase oxidative stress and cause neuron damage in the hippocampus.

Alpha-Melanocyte-Stimulating Hormone is Elevated in Hypothalamic Obesity Associated with Childhood Craniopharyngioma

OBJECTIVE

The purpose of this study was to investigate the peripheral concentrations of leptin and neuropeptides taking part in the melanocortin pathway in hypothalamic obesity (HO) associated with craniopharyngioma (CP) and to find a peripheral marker for diagnosis.

METHODS

Thirty-one patients (52% girls; median age 16 years) with CP were enrolled in the study group. They were grouped as CP with obesity (CP^obesity , n = 17) and CP without obesity (CP^nonobesity , n = 14). Two control groups without CP consisted of 27 children with obesity (OC) (55% girls; median age 13.8 years) and 25 children without obesity (normal control [NC]) (72% girls; median age 14.5 years). Obesity was defined as BMI percentile ≥ 95%. Fasting serum concentrations of leptin, brain-derived neurotrophic factor (BDNF), and alpha-melanocyte-stimulating hormone (α-MSH) were measured in the groups.

RESULTS

Leptin and BDNF concentrations were correlated with BMI SD score (SDS) in controls (OC + NC) and CP. However, there was no correlation between α-MSH and BMI-SDS in CP or control groups. After adjusting for age, sex, and BMI-SDS, α-MSH was found to be significantly higher in CP^obesity than in other groups, whereas leptin and BDNF were comparable among the four groups.

CONCLUSIONS

Serum BDNF, just like leptin, increased with BMI, regardless of hypothalamic damage. On the contrary, α-MSH concentration was significantly high in HO, designating a potential biomarker for HO in CP.

BDNF influences neural cue-reactivity to food stimuli and food craving in obesity

There is increasing evidence that brain-derived neurotrophic factor (BDNF) impacts on the development of obesity. We are the first to test the hypothesis that BDNF levels might be associated with neural reactivity to food cues in patients suffering from obesity and healthy controls. We assessed visual food cue-induced neural response in 19 obese patients and 20 matched controls using functional magnetic resonance imaging and analyzed the associations between BDNF levels, food cue-reactivity and food craving. Whole-brain analysis in both groups revealed that food cues elicited higher neural activation in clusters of mesolimbic brain areas including the insula (food > neutral). Patients suffering from obesity showed a significant positive correlation between plasma BDNF levels and visual food cue-reactivity in the bilateral insulae. In addition, patients suffering from obesity with positive food cue-induced insula activation also reported significantly higher food craving than those with low cue-reactivity-an effect that was absent in normal weight participants. The present findings implicate that BDNF levels in patients suffering from obesity might be involved in food craving and obesity in humans. This highlights the importance to consider BDNF pathways when investigating obesity and obesity treatment.

Genetic polymorphisms in neuroendocrine disorder-related candidate genes associated with pre-pregnancy obesity in gestational diabetes mellitus patients by using a stratification approach

Background

Certain candidate genes have been associated with obesity. The goal of this study is to determine the association between thirteen neuroendocrine disorder-related candidate genes and pre-pregnancy obesity among gestational diabetes mellitus (GDM) patients using the stratification approach defined the Asian and International criteria-based body mass index (BMI).

Methods

This was a post-hoc case-control exploratory sub-analysis of a cross-sectional study among GDM women to determine which candidate single nucleotide polymorphisms (SNPs) related to neuroendocrine disorders may be associated with obesity. Factors were adjusted for socio-demographic characteristics and concurrent medical problems in this particular population. Pre-pregnancy BMI and concurrent medical profiles were obtained from maternal health records. Obesity is defined as BMI of ≥27.5 kg/m² for Asian criteria-based BMI and >30 kg/m² for International criteria-based BMI. Thirteen candidate genes were genotyped using Agena^® MassARRAY and examined for association with pre-pregnancy obesity using multiple logistic regression analysis. The significant difference threshold was set at P value <0.05.

Results

Three hundred and twelve GDM women were included in this study; 60.9% and 44.2% of GDM patients were obese using Asian and International criteria-based BMI, respectively. GDM patients with AA or AG genotypes in specific SNP of brain-derived neurotrophic factor (BDNF) (G > A in rs6265) are more likely to be obese (adjusted odd ratio =2.209, 95% CI, 1.305, 3.739, P=0.003) compared to those who carry the GG genotype in the SNP adjusted for parity, underlying with asthma, heart disease, anaemia, education background in the International criteria-based BMI stratification group. On the other hand, there were no associations between other candidate genes (NRG1, FKBP5, RORA, OXTR, PLEKHG1, HTR2C, LHPP, SDK2, TEX51, EPHX2, NPY5R and ANO2) and maternal obesity.

Conclusions

In summary, BDNF rs6265 is significantly associated with pre-pregnancy obesity among GDM patients. The exact role of BDNF adjusted for diet intake and lifestyle factors merits further investigation.

Brain-Derived Neurotrophic Factor during Oral Glucose Tolerance Test Predicts Cardiovascular Outcomes

We investigated if brain-derived neurotrophic factor (BDNF) accumulation after glucose intake could predict cardiovascular outcomes. We enrolled patients admitted for angiography due to angina. After their conditions stabilized, serum BDNF levels were detected at 0, 30, and 120 min during oral glucose tolerance test (OGTT). Area under the curve (AUC) of BDNF was calculated. The first occurrence of nonfatal myocardial infarction, nonfatal stroke, and all-cause mortality served as the primary composite endpoint. Of 480 enrolled patients, 428 completed the follow-up, and 36 primary endpoint events occurred during a median follow-up of 4.4 years. The area under the receiver operating characteristic curve significantly increased from 0.61 (95% confidence interval (CI): 0.52–0.73) for the Framingham risk score (FRS) alone model to 0.72 (95%CI: 0.63–0.81) for the AUC of BDNF plus FRS model (p = 0.016) for predicting the primary endpoint, but not to 0.65 (95%CI: 0.55–0.75) for the fasting BDNF plus FRS model (p = 0.160). Grouped by median AUC of BDNF of 38.0 (ng/mL) × h, the low BDNF group had a significantly higher risk of the endpoint than the high BDNF group (hazard ratio = 3.410, 95%CI: 1.520–7.653, p = 0.003). In conclusion, AUC of BDNF during OGTT could be superior to fasting BDNF for predicting a low cardiovascular risk.

Sedentarism, Physical Activity, Steps, and Neurotrophic Factors in Obese Children

PURPOSE

This study aimed to examine the associations of sedentary time, physical activity (PA) and step-related behaviors with neurotrophic growth factors.

METHODS

A total of 97 children with overweight/obesity age 8 to 11 yr participated in this study. Sedentary time, PA, and steps were measured by GT3X+ accelerometers in hip and nondominant wrist. Estimates of light, moderate, vigorous, and moderate-to-vigorous PA (MVPA) were obtained. Steps per daytime, peak 60-, 30-, and 1-min cadence were computed. The time accumulated (min·d) in different cadence bands of steps was also computed from hip accelerometer. Plasma levels of brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), and insulin growth factor-1 (IGF-1) were determined by the XMap technology (Luminex IS 100/200 system, Luminex Corporation, Austin, TX).

RESULTS

Light PA, moderate PA, MVPA, and the peak 60-min cadence were positively related with BDNF concentrations (all P < 0.05), and only light PA to VEGF (P = 0.048). No association was observed for IGF-1 (P > 0.05). The associations of light PA with BDNF and VEGF disappeared (all P > 0.05) after performing analyses with nondominant wrist-placement data. However, moderate PA and MVPA remained significantly associated with BDNF (both P < 0.05). The time accumulated in cadence bands of 40 to 59 steps per day and 60 to 79 steps per day (i.e., walking at slow pace) was positively associated with plasma BDNF (all P < 0.05).

CONCLUSIONS

In conclusion, PA is positively related to plasma BDNF, whereas no relationship was observed for VEGF or IGF-1. Higher amounts of time spent in slow walking cadence bands could increment BDNF levels. Exercise-based randomized controlled trials in children with overweight/obesity should be carried out to better understand the influence of PA behaviors on the neurotrophic factors.

A Cross-Sectional Study Evaluating the Effects of Resistance Exercise on Inflammation and Neurotrophic Factors in Elderly Women with Obesity

PURPOSE

Aging lowers brain functionality, and obesity accelerates this process. Resistance exercise can help reverse aging; however, studies examining how it affects brain function and body mass are limited. Thus, this study aimed to investigate the effect of resistance exercise on inflammation and neurotrophic factors in elderly women with obesity.

METHODS

Twenty-six elderly women with obesity were selected for this study and randomly assigned into a control group (CG, n = 13) and an experimental group (EG, n = 13). The EG performed resistance training thrice weekly for 12 weeks using elastic bands, while the CG did not exercise. Serum lipid profile (total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C)) and nuclear factor Kappa B (NF-κB), interferon-gamma (IFN-γ), brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), and eotaxin-1 levels were analyzed before and after the intervention. Body composition (soft lean mass (SLM), skeletal muscle mass (SMM), body fat mass (BFM), percent body fat (PBF), waist-hip-ratio (WHR), basal metabolic rates (BMR)) measurements and blood tests were performed.

RESULTS

Among the body composition variables, SLM, SMM, and BMR in the EG were significantly increased after intervention (p < 0.05). Serum lipid profile was not significantly different after intervention (p > 0.05). After intervention, the levels of NF-κB, IFN-γ, and eotaxin-1 were significantly lower and BDNF and VEGF were significantly higher in the EG than in the CG (p < 0.05 for all).

CONCLUSIONS

These results imply that regular resistance training in elderly women with obesity can increase muscle mass, reduce inflammation, and stimulate neurotrophic factors.

Changes in appetite-regulating hormones following food intake are associated with changes in reported appetite and a measure of hedonic eating in girls and young women with anorexia nervosa

BACKGROUND

Females with anorexia nervosa (AN) have higher ghrelin and peptide YY (PYY) and lower brain-derived neurotropic factor (BDNF) levels than controls, and differ in their perception of hunger cues. Studies have not examined appetite-regulating hormones in the context of homeostatic and hedonic appetite in AN.

OBJECTIVE

To examine whether alterations in appetite-regulating hormones following a standardized meal are associated with homeostatic and hedonic appetite in young females with AN vs. controls.

METHODS

68 females (36 AN, 32 controls) 10-22 years old were enrolled. Ghrelin, PYY and BDNF levels were assessed before, and 30, 60 and 120 min following a 400-kilocalorie standardized breakfast. Visual Analog Scales (VAS) assessing prospective food consumption, hunger, satiety, and hedonic appetite were administered before and 20 min after breakfast. A Cookie Taste Test (CTT) was conducted after a snack as a measure of hedonic eating behavior ∼3 h after breakfast.

RESULTS

AN had higher fasting ghrelin and PYY, and lower fasting BDNF (p = 0.001, 0.002 and 0.044 respectively) than controls. Following breakfast (over 120 min), ghrelin and PYY area under the curve (AUC) were higher, while BDNF AUC was lower in AN vs. controls (p = 0.007, 0.017 and 0.020 respectively). Among AN (but not controls), reductions in ghrelin and increases in PYY in the first 30-minutes following breakfast were associated with reductions in VAS scores for prospective food consumption. AN consumed fewer calories during the CTT vs. controls (p < 0.0001). In AN (particularly AN-restrictive subtype), BDNF AUC was positively associated with kilocalories consumed during the CTT CONCLUSIONS: In young females with AN, changes in ghrelin and PYY following food intake are associated with reductions in a prospective measure of food consumption, while reductions in BDNF are associated with reduced hedonic food intake. Further studies are necessary to better understand the complex interplay between appetite signals and eating behaviors in AN.

BDNF Val66Met genetic variation and its plasma level in patients with morbid obesity: A case-control study

Obesity is a major public health concern worldwide. Genetic, behavioral, and environmental factors contribute to the multifactorial etiology of obesity. Evidence suggests an association between human Brain-Derived Neurotrophic Factor (BDNF) Val66Met single nucleotide polymorphism (SNP) and obesity. Reduced plasma BDNF levels have also been reported in patients with eating disorders and obesity. We aimed to evaluate the BDNF Val66Met (rs6265) SNP and also plasma BDNF levels in morbidly obese patients compared with healthy normal controls in southern Iran. One hundred morbidly obese patients and one hundred eight healthy normal controls were enrolled. Blood-derived DNA samples were genotyped using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and confirmed by DNA sequencing. Plasma BDNF levels were evaluated using a commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kit for human BDNF. Data analysis was performed by SPSS software, version 18.0. Genotype distribution was not significantly different between obese patients and controls. However, plasma BDNF levels were significantly lower in obese patients compared with controls. Interestingly, a significant association was found between BDNF Val66Met SNP and plasma BDNF levels. No relationship was observed between BDNF Val66Met SNP and all assessed demographic and clinical characteristics of obese patients. It seems that plasma BDNF levels were associated with both obesity and BDNF Val66Met SNP. However, this association was not found between BDNF Val66Met SNP and obesity. Further studies with larger sample sizes are needed for more detailed assessment of this genetic variation as a potential biomarker for obesity.

The role of neurotrophins in psychopathology and cardiovascular diseases: psychosomatic connections

Cardiovascular (CV) diseases and mood disorders are common public health problems worldwide. Their connections are widely studied, and the role of neurotrophins (NTs) is already supposed in both conditions. However, data in the literature of clinical aspects are sometimes controversial and no reviews are available describing possible associations between CV risk and mood disorders based on NTs. The mostly studied NT is brain-derived neurotrophic factor (BDNF). Decreased level of BDNF is observed in depression and its connection to hypertension has also been demonstrated with affecting the arterial baroreceptors, renin–angiotensin system and endothelial nitric oxide synthase. BDNF was also found to be the predictor of CV outcome in different patient populations. Other types of human NT-s, such as nerve growth factor, neurotrophin 3 and neurotrophin 4 also seem to have both psychopathological and CV connections. Our aim was to overview the present knowledge in this area, demonstrating a new aspect of the associations between mood disorders and CV diseases through the mediation of NTs. These findings might enlighten new psychosomatic connections and suggest new therapeutic targets that are beneficial both in respect of mood disorders and CV pathology.

Acute high-intensity interval exercise induces greater levels of serum brain-derived neurotrophic factor in obese individuals

Obesity may attenuate the expression of brain-derived neurotrophic factor (BDNF), thereby increasing the risk of cognitive dysfunction. High-intensity interval exercise (HIIE) has been shown to be as or more effective than continuous moderate-intensity exercise (CME) in promoting the expression of BDNF in normal-weight individuals. Therefore, the primary purpose of this study was to examine whether or not acute HIIE could be utilized as a practical model to explore the BDNF response in obese versus normal-weight subjects when compared to acute CME. The potential relationship of exercise-induced BDNF with blood lactate and cortisol was also examined. Twelve male subjects (six obese and six normal-weight) participated in a counterbalanced and caloric equated experiment: HIIE (30 min, 4 intervals of 4 min at 80%–90% of VO2max with 3 min of active recovery at 50–60% VO2max) and CME (38 min at 50%–60% VO2max). Blood samples were collected prior to, immediately following exercise, and 1 h into recovery for measurements of serum BDNF, blood lactate, and plasma cortisol. Our results showed that the BDNF response to acute HIIE was greater than CME in obese subjects when compared to normal-weight subjects. Similarly, although acute HIIE induced greater blood lactate and plasma cortisol levels than CME, obese subjects produced less blood lactate, but no difference in cortisol than normal-weight subjects. These findings suggest that acute HIIE may be a more effective protocol to upregulate BDNF expression in an obese population, independent of increased lactate and cortisol levels.

Impact statement

High-intensity interval exercise (HIIE) has been shown to be a time-efficient exercise strategy that provides similar or superior physiological benefits as traditional continuous moderate-intensity exercise (CME). Our previous study demonstrated an equivalent elevation on the BDNF response in both obese and normal-weight individuals following 30 min of acute CME. To discover a time-efficient exercise strategy to improve brain health in an obese population, the present study found that obese individuals elicit a greater level of BDNF following acute HIIE versus CME than normal-weight individuals. These findings indicate that acute HIIE may be an effective strategy to upregulate BDNF expression in obese individuals.

Changes in the Brain-Derived Neurotrophic Factor Are Associated with Improvements in Diabetes Risk Factors after Exercise Training in Adolescents with Obesity: The HEARTY Randomized Controlled Trial

Obesity in youth increases the risk of type 2 diabetes (T2D), and both are risk factors for neurocognitive deficits. Exercise attenuates the risk of obesity and T2D while improving cognitive function. In adults, these benefits are associated with the actions of the brain-derived neurotrophic factor (BDNF), a protein critical in modulating neuroplasticity, glucose regulation, fat oxidation, and appetite regulation in adults. However, little research exists in youth. This study examined the associations between changes in diabetes risk factors and changes in BDNF levels after 6 months of exercise training in adolescents with obesity. The sample consisted of 202 postpubertal adolescents with obesity (70% females) aged 14-18 years who were randomized to 6 months of aerobic and/or resistance training or nonexercise control. All participants received a healthy eating plan designed to induce a 250/kcal deficit per day. Resting serum BDNF levels and diabetes risk factors, such as fasting glucose, insulin, homeostasis model assessment (HOMA-B-beta cell insulin secretory capacity) and (HOMA-IS-insulin sensitivity), and hemoglobin A1c (HbA1c), were measured after an overnight fast at baseline and 6 months. There were no significant intergroup differences on changes in BDNF or diabetes risk factors. In the exercise group, increases in BDNF were associated with reductions in fasting glucose (β = -6.57, SE = 3.37, p = 0.05) and increases in HOMA-B (β = 0.093, SE = 0.03, p = 0.004) after controlling for confounders. No associations were found between changes in diabetes risk factors and BDNF in controls. In conclusion, exercise-induced reductions in some diabetes risk factors were associated with increases in BDNF in adolescents with obesity, suggesting that exercise training may be an effective strategy to promote metabolic health and increases in BDNF, a protein favoring neuroplasticity. This trial is registered with ClinicalTrials.gov NCT00195858, September 12, 2005 (funded by the Canadian Institutes of Health Research).

Peripheral Blood Brain-Derived Neurotrophic Factor as a Biomarker of Alzheimer's Disease: Are There Methodological Biases?

Mounting evidence that alterations in brain-derived neurotrophic factor (BDNF) levels and signaling may be involved in the etiopathogenesis of Alzheimer's disease (AD) has suggested that its blood levels could be used as a biomarker of the disease. However, higher, lower, or unchanged circulating BDNF levels have all been described in AD patients compared to healthy controls. Although the reasons for such different findings are unclear, methodological issues are likely to be involved. The heterogeneity of participant recruitment criteria and the lack of control of variables that influence circulating BDNF levels regardless of dementia (depressive symptoms, medications, lifestyle, lack of overlap between serum and plasma, and experimental aspects) are likely to bias result and prevent study comparability. The present work reviews a broad panel of factors, whose close control could help reduce the inconsistency of study findings, and offers practical advice on their management. Research directed at elucidating the weight of each of these variables and at standardizing analytical methodologies is urgently needed.

Association of Brain-Derived Neurotrophic Factor and Vitamin D with Depression and Obesity: A Population-Based Study

BACKGROUND

Depression and obesity are widespread and closely linked. Brain-derived neurotrophic factor (BDNF) and vitamin D are both assumed to be associated with depression and obesity. Little is known about the interplay between vitamin D and BDNF. We explored the putative associations and interactions between serum BDNF and vitamin D levels with depressive symptoms and abdominal obesity in a large population-based cohort.

METHODS

Data were obtained from the population-based Study of Health in Pomerania (SHIP)-Trend (n = 3,926). The associations of serum BDNF and vitamin D levels with depressive symptoms (measured using the Patient Health Questionnaire) were assessed with binary and multinomial logistic regression models. The associations of serum BDNF and vitamin D levels with obesity (measured by the waist-to-hip ratio [WHR]) were assessed with binary logistic and linear regression models with restricted cubic splines.

RESULTS

Logistic regression models revealed inverse associations of vitamin D with depression (OR = 0.966; 95% CI 0.951-0.981) and obesity (OR = 0.976; 95% CI 0.967-0.985). No linear association of serum BDNF with depression or obesity was found. However, linear regression models revealed a U-shaped association of BDNF with WHR (p < 0.001).

CONCLUSION

Vitamin D was inversely associated with depression and obesity. BDNF was associated with abdominal obesity, but not with depression. At the population level, our results support the relevant roles of vitamin D and BDNF in mental and physical health-related outcomes.

A Longitudinal Analysis of the Relationships of Physical Activity and Body Fat With Nerve Growth Factor and Brain-Derived Neural Factor in Children

BACKGROUND

Nerve growth factor (NGF) and brain-derived neural factor (BDNF) are important for brain function and detectable in the blood. This study explored the longitudinal associations of physical activity and body fat with serum NGF and BDNF in children.

METHODS

Two waves of measurements were performed 2 years apart in 8- to 11-year-old children, including physical activity using the ActiGraph model 7164, body composition by dual-energy X-ray absorptiometry, and serum NGF and BDNF determined by multiplex immunoassay. The first wave included 248 children. Full information maximum likelihood estimation with robust standard errors was applied in structural equation modeling.

RESULTS

Vigorous physical activity showed a direct positive longitudinal relationship with NGF (standardized coefficient β = 0.30, P = .01) but not with BDNF (β = 0.04, P = .84). At the same time, body fat percentage was positively related to both NGF (β = 0.59, P < .001) and BDNF (β = 0.17, P = .04). There was an indication of an indirect relationship of vigorous physical activity with NGF (product of unstandardized coefficient β = -0.18, P = .02) and BDNF (β = -0.07, P = .05) through the negative relationship with body fat percentage (β = -0.36, P < .001).

CONCLUSIONS

Vigorous physical activity is directly related to serum NGF and indirectly through the level of body fat. The relationships with serum BDNF are more complex.

Exercise-induced increase in brain-derived neurotrophic factor in human Parkinson's disease: a systematic review and meta-analysis

Background

Animal models of exercise and Parkinson’s disease (PD) have found that the physiologic use of exercise may interact with the neurodegenerative disease process, likely mediated by brain derived neurotrophic factor (BDNF). No reviews so far have assessed the methodologic quality of available intervention studies or have bundled the effect sizes of individual studies on exercise-induced effects on BDNF blood levels in human PD.

Research design and methods

We searched MEDLINE, EMBASE, Cochrane Library, PsycINFO and PubMed from inception to June 2017.

Results

Data aggregated from two randomized controlled trials and four pre-experimental studies with a total of 100 ambulatory patients with idiopathic PD (Hoehn/Yahr ≤3) found improvements in BDNF blood concentration levels in all 6 studies (two RCTs and 4 pre-experimental studies). Pooled BDNF level change scores from the 2 RCTs resulted in a significant homogeneous summary effect size (Standardized Mean Difference 2.06, 95% CI 1.36 to 2.76), and a significant heterogeneous SES for the motor part of the UPDRS-III examination (MD -5.53, 95% CI -10.42 to -0.64). Clinical improvements were noted in all studies using a variety of outcome measures.

Limitations

The evidence-base consists primarily of small studies with low to moderate methodological quality.

Conclusions

This review provides preliminary evidence for the effectiveness of physical exercise treatments for persons with PD on BDNF blood levels. Further research is needed.

Electronic supplementary material

The online version of this article (10.1186/s40035-018-0112-1) contains supplementary material, which is available to authorized users.

Association of Brain-derived neurotrophic factor gene polymorphisms with body mass index: A systematic review and meta-analysis

BACKGROUND

Many studies with inconsistent results have assessed the association of Brain-derived neurotrophic factor (BDNF) gene polymorphisms with prevalence of obesity and overweight. This review aims to provide a summary of the literature evaluating the relation between BDNF genotype and body mass index (BMI).

METHODS

A systematic search through PubMed, Scopus, Science direct, Ovid and Cochrane was performed. We included observational studies with cross-sectional and case-control design, which investigated relationship between all kinds of BDNF polymorphisms with BMI, as a representative index of obesity and overweight. Newcastle-Ottawa Scale was used to assess the quality of included articles.

RESULTS

Thirty five studies were included in quantitative synthesis. Analyses were performed separately using OR, β coefficient and mean. Significant association were documented between rs925946 and BMI (OR=1.12, 95% CI=1.08-1.17, P heterogeneity=0.317), rs10501087 and BMI (OR=1.14, 95% CI=1.04-1.24, P heterogeneity=0.861), rs6265 and BMI (OR=1.13, 95% CI=1.07-1.19, P heterogeneity=0.406), rs988712 and BMI (OR=1.29, 95% CI=1.18-1.40, P heterogeneity=0.602). According to pooled β coefficient analysis, significant result was only observed in the rs925946 polymorphism subgroup. Pooled mean analysis showed that overall effects for the association between BDNF polymorphisms and BMI were not statistically significant.

CONCLUSION

This meta-analysis suggests that some polymorphisms in BDNF gene including rs925946, rs10501087, rs6265 and rs988712 can be considered as genetic determinants of obesity.

The effects of aerobic exercise training on oxidant-antioxidant balance, neurotrophic factor levels, and blood-brain barrier function in obese and non-obese men

PURPOSE

The purpose of this study was to investigate the effects of obesity and aerobic exercise training on oxidant-antioxidant balance, neurotrophic factor levels, and blood-brain barrier (BBB) function.

METHODS

Ten non-obese healthy men (body mass index < 25 kg/m²) and 10 obese men (body mass index ≥ 25 kg/m²) were included in the study. Both groups performed treadmill exercise for 40 min 3 times weekly for 8 weeks at 70% heart rate reserve. Blood samples were collected to examine oxidant-antioxidant balance (reactive oxygen species (ROS) and superoxide dismutase (SOD) activity levels), neurotrophic factors (brain-derived neurotrophic factor (BDNF), nerve growth factor, and glial cell line-derived neurotrophic factor levels), and BBB function (S100β and neuron-specific enolase (NSE) levels) before and after exercise training.

RESULTS

The obese group showed significantly greater changes than the non-obese group in serum ROS (-0.46 ± 0.31 mmol/L vs. -0.10 ± 0.17 mmol/L, p = 0.005), serum S100β levels (-8.50 ± 5.92 ng/L vs. -0.78 ± 5.45 ng/L, p = 0.007), and serum NSE levels (-0.89 ± 0.54 µg/L vs. -0.01 ± 0.74 µg/L, p = 0.007) after training. At baseline, the obese group showed significantly higher serum ROS and S100β levels and significantly lower serum SOD activity and BDNF levels than the non-obese group (p < 0.05). The obese group showed significantly lower serum ROS, S100β, and NSE levels and significantly higher serum SOD activity and BDNF levels after training compared with baseline (p < 0.05).

CONCLUSION

These results suggest that obesity can reduce serum neurotrophic factor levels and can induce BBB dysfunction. On the other hand, aerobic exercise can improve an oxidant-antioxidant imbalance in obese subjects and limit BBB dysfunction.

Correlates of early pregnancy serum brain-derived neurotrophic factor in a Peruvian population

Knowledge about factors that influence serum brain-derived neurotrophic factor (BDNF) concentrations during early pregnancy is lacking. The aim of the study is to examine the correlates of early pregnancy serum BDNF concentrations. A total of 982 women attending prenatal care clinics in Lima, Peru, were recruited in early pregnancy. Pearson's correlation coefficient was calculated to evaluate the relation between BDNF concentrations and continuous covariates. Analysis of variance and generalized linear models were used to compare the unadjusted and adjusted BDNF concentrations according to categorical variables. Multivariable linear regression models were applied to determine the factors that influence early pregnancy serum BDNF concentrations. In bivariate analysis, early pregnancy serum BDNF concentrations were positively associated with maternal age (r = 0.16, P < 0.001) and early pregnancy body mass index (BMI) (r = 0.17, P < 0.001), but inversely correlated with gestational age at sample collection (r = -0.21, P < 0.001) and C-reactive protein (CRP) concentrations (r = -0.07, P < 0.05). In the multivariable linear regression model, maternal age (β = 0.11, P = 0.001), early pregnancy BMI (β = 1.58, P < 0.001), gestational age at blood collection (β = -0.33, P < 0.001), and serum CRP concentrations (β = -0.57, P = 0.002) were significantly associated with early pregnancy serum BDNF concentrations. Participants with moderate antepartum depressive symptoms (Patient Health Questionnaire-9 (PHQ-9) score ≥ 10) had lower serum BDNF concentrations compared with participants with no/mild antepartum depressive symptoms (PHQ-9 score < 10). Maternal age, early pregnancy BMI, gestational age, and the presence of moderate antepartum depressive symptoms were statistically significantly associated with early pregnancy serum BDNF concentrations in low-income Peruvian women. Biological changes of CRP during pregnancy may affect serum BDNF concentrations.

The association between brain-derived neurotrophic factor and central pulse pressure after an oral glucose tolerance test

BACKGROUND

Arterial stiffening blunts postprandial vasodilatation. We hypothesized that brain-derived neurotrophic factor (BDNF) may modulate postprandial central pulse pressure, a surrogate marker for arterial stiffening.

METHODS

A total of 82 non-diabetic subjects received a 75-g oral glucose tolerance test (OGTT) after overnight fasting. Serum BDNF concentrations were determined at 0, 30, and 120min to calculate the area under the curve (AUC). Brachial and central blood pressures were measured using a noninvasive central blood pressure monitor before blood withdrawals at 0 and 120min.

RESULTS

With the median AUC of BDNF of 45(ng/ml)∗h as the cutoff value, the central pulse pressure after glucose intake was significantly higher in the subjects with a low BDNF than in those with a high BDNF (63±16 vs. 53±11mmHg, P=0.003), while the brachial pulse pressure was not significantly different between the 2 groups (P=0.099). In a multivariate linear regression model, a lower AUC of BDNF was an independent predictor of a higher central pulse pressure after oral glucose intake (linear regression coefficient-0.202, 95% confidence interval-0.340 to -0.065, P=0.004).

CONCLUSION

After oral glucose challenge, a lower serum BDNF response is significantly associated with a higher central pulse pressure.

The association between serum brain-derived neurotrophic factor and a cluster of cardiovascular risk factors in adolescents: The CHAMPS-study DK

Background and objective

Cardiovascular disease and type 2 diabetes pose a global health burden. Therefore, clarifying the pathology of these risk factors is essential. Previous studies have found positive and negative associations between one or more cardiovascular risk factors and brain-derived neurotrophic factor (BDNF) probably due to diverse methodological approaches when analysing peripheral BDNF levels. Moreover, only a few studies have been performed in youth populations. Consequently, the main objective of this study was to examine the association between serum BDNF and a composite z-score consisting of six cardiovascular risk factors. A secondary aim was to examine the associations between serum BDNF and each of the six risk factors.

Methods

Four hundred and forty-seven apparently healthy adolescents between 11–17 years of age participated in this cross-sectional study. Cardiorespiratory fitness (CRF), anthropometrics, pubertal status, blood pressure (BP), serum BDNF, high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), blood glucose and insulin were measured. Information about alcohol consumption and socio-economic status was collected via questionnaires. Associations were modelled using linear regression analysis.

Results

Serum BDNF was positively associated with the composite z-score in the total study sample (standardized beta coefficient (std.β) = 0.10, P = 0.037). In males, serum BDNF was positively associated with the composite z-score (Std. β = 0.14, P = 0.034) and HOMA-IR (Std. β = 0.19, P = 0.004), and negatively associated with CRF (Std. β = -0.15, P = 0.026). In females, BDNF was positively associated with TG (Std. β = 0.14, P = 0.030) and negatively associated with waist circumference (WC) (Std. β = -0.16, P = 0.012).

Conclusion

Serum BDNF was positively associated with a composite z-score of cardiovascular risk factors. This association seems to be mainly driven by the association between TG, HOMA-IR and serum BDNF, and particularly for males. Further longitudinal research is warranted to determine the temporal relationship between BDNF and cardiovascular risk factors.

Plasma but not serum brain-derived neurotrophic factor concentration is decreased by oral glucose tolerance test-induced hyperglycemia in children

BACKGROUND

Little is known regarding the relationships among circulating brain-derived neurotrophic factor (BDNF) levels and glucose or insulin in children and adolescents. The objective of this study was to investigate whether circulating BDNF levels would change during the oral glucose tolerance test (OGTT).

METHODS

We performed the OGTT and measured the serial changes in BDNF levels in both plasma and serum.

RESULTS

There were 22 subjects in the normal type (N) group and 20 in the borderline/diabetic type (B/D) group, defined by the results of the OGTT. Serum levels of BDNF were almost five times higher and plasma levels gradually decreased during the OGTT, whereas serum levels showed no significant change. The reduction of plasma BDNF level changes from baseline to 120 min were significantly different between the N and B/D groups (36.3% vs. 20.8%, p=0.023).

CONCLUSIONS

Our results showed that plasma levels of BDNF are more sensitive to acute changes in glucose or insulin levels than serum.

The synergistic effect of vascular cell adhesion molecule-1 and coronary artery disease on brain-derived neurotrophic factor

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is important for neural protection and energy homeostasis. In this study, we examined the effects of vascular cell adhesion molecule-1 (VCAM-1) and coronary artery disease (CAD) on BDNF.

METHODS

Subjects who had undergone diagnostic angiography for angina were recruited, and a total of 240 subjects (144 with CAD and 96 without CAD) were enrolled. Serum BDNF was determined at 0, 30, and 120min during an oral glucose tolerance test (OGTT) to calculate the area under the curve (AUC) for BDNF. Serum VCAM-1 was determined at fasting.

RESULTS

Significantly lower AUC of BDNF (42.8±10.7 vs. 47.4±11.7ng-h/ml, P=0.002) and higher serum VCAM-1 (583±383 vs. 482±171ng/ml, P=0.017) were noted in subjects with CAD compared to those without CAD. High VCAM-1 level was an independent predictor of low AUC of BDNF in subjects with and without CAD (95%CI between -0.011 and -0.002, P=0.008; -0.033 and -0.002, P=0.029, respectively). Serum BDNF was lowest in the CAD subjects with high VCAM-1 levels at all time points during OGTT.

CONCLUSION

Our results showed that CAD was associated with low serum BDNF in response to OGTT, and VCAM-1 had a synergistic effect with CAD on the BDNF.

High-flavonoid intake induces cognitive improvements linked to changes in serum brain-derived neurotrophic factor: Two randomised, controlled trials

BACKGROUND: Recent clinical studies have indicated the beneficial impact of dietary flavonoid intake on human cognitive performance. Although the mechanisms that mediate such improvements are currently unclear, animal and human trial data suggest that changes in neurotrophin expression, and related signalling apparatus, may be involved.

OBJECTIVE: To investigate the link between changes in serum brain-derived neurotrophic factor (BDNF) and changes in human cognitive performance following flavonoid intake.

METHODS: The relationship between serum levels of BDNF and age, gender, BMI, waist circumference, blood pressure and cognition at baseline, and following flavonoid intake, was investigated in two distinct randomised, controlled clinical trials. Trial 1 was conducted in men and women (aged 26–70 y; consuming an average of 3 portions of fruit and vegetables per day) and delivered high-flavonoid (>15 mg/100 g) or low-flavonoid (<5 mg/100 g) fruit and vegetables and increased intake by 2 portions every 6 weeks. The control arm was habitual diet over the same time frame. Trial 2 was conducted in an older males and female cohort (aged 62–75 y) intervening with a high-flavanol cocoa drink (494 mg total flavanols) and a low-flavanol cocoa drink (23 mg total flavanols) for 12 weeks.

RESULTS: Serum BDNF levels increased linearly to the age of 65, after which BDNF levels were found to decrease markedly. All other physiological and anthropometric measurements proved to not be significantly associated with serum BDNF levels (p > 0.05), although higher levels in males compared to females almost achieved significance (p = 0.056). At baseline, higher serum BDNF levels were associated with significantly better global cognition scores, relative to individuals with lower serum levels. In addition, following intervention for 18 weeks, high-flavonoid, but not low-flavonoid, fruit and vegetable intake induced significant improvements in cognitive performance and increases in serum BDNF levels (p = <0.001). Flavanol intervention for 12 weeks also resulted in significant increases in serum BDNF (p = <0.001), and such increases were correlated with improvements in global cognitive performance.

CONCLUSION: Increases in global cognition induced by high flavonoid fruit and vegetables, and cocoa flavanols were paralleled by concurrent changes in serum BDNF levels, suggesting a role for BDNF in flavonoid-induced cognitive improvements. Furthermore, we provide further data suggesting that serum BDNF levels may represent a biomarker of cognitive function.

Effect of chronic consumption of blackberry extract on high-fat induced obesity in rats and its correlation with metabolic and brain outcomes

Flavonoids have been presented as potential protectors against metabolic and cognitive dysfunction. However, mechanisms underlying these 'claims' have not been sufficiently explored. To analyse the effect of long-term supplementation with blackberry extract (BE) in the context of a high-fat or a standard diet, Wistar rats were divided into 4 groups (n = 6) fed with a standard or a high-fat diet, with or without BE supplementation at 25 mg per kg body weight per day. A high-fat diet significantly impaired glucose tolerance and increased body weight, caloric ingestion, very-low-density lipoprotein, triglycerides and cholesterol. Furthermore, it was observed that a high-fat diet increased dopamine content in the prefrontal cortex and decreased brain derived neurotrophic factor (BDNF) levels both in the prefrontal cortex and in plasma. BE supplementation only affected some of these aspects. BE slightly improved glucose metabolism and significantly decreased levels of lactate, independent of diet. BE decreased levels of BDNF and also interacted with the dopaminergic system, increasing dopamine turnover in the striatum, and reverting dopamine content induced by a high-fat diet in the prefrontal cortex. This study shows that, despite some particular benefits of anthocyanin supplementation, some long-term effects may not be desirable and further studies are needed to optimize ingestion conditions.

Tumour biology of obesity-related cancers: understanding the molecular concept for better diagnosis and treatment

Obesity continues to be a major global problem. Various cancers are related to obesity and proper understanding of their aetiology, especially their molecular tumour biology is important for early diagnosis and better treatment. Genes play an important role in the development of obesity. Few genes such as leptin, leptin receptor encoded by the db (diabetes), pro-opiomelanocortin, AgRP and NPY and melanocortin-4 receptors and insulin-induced gene 2 were linked to obesity. MicroRNAs control gene expression via mRNA degradation and protein translation inhibition and influence cell differentiation, cell growth and cell death. Overexpression of miR-143 inhibits tumour growth by suppressing B cell lymphoma 2, extracellular signal-regulated kinase-5 activities and KRAS oncogene. Cancers of the breast, uterus, renal, thyroid and liver are also related to obesity. Any disturbance in the production of sex hormones and insulin, leads to distortion in the balance between cell proliferation, differentiation and apoptosis. The possible mechanism linking obesity to cancer involves alteration in the level of adipokines and sex hormones. These mediators act as biomarkers for cancer progression and act as targets for cancer therapy and prevention. Interestingly, many anti-cancerous drugs are also beneficial in treating obesity and vice versa. We also reviewed the possible link in the mechanism of few drugs which act both on cancer and obesity. The present review may be important for molecular biologists, oncologists and clinicians treating cancers and also pave the way for better therapeutic options.

The relationship between brain-derived neurotrophic factor, irisin and cognitive skills of endurance athletes

OBJECTIVE

The objective of this study was to assess the cognitive performance of endurance athletes and its relation with circulating brain-derived neurotrophic factor (BDNF) and irisin levels.

METHODS

26 endurance athletes (14 elite orienteers (mean ± SD: age = 26.33 ± 4.08, body weight = 70.33 ± 4.64, body height = 177.7 ± 6.1), 12 pentathletes (mean ± SD: age = 29.42 ± 5.32, body weight = 74.77 ± 6.59, body height = 180.8 ± 3.8)) and ten sedentary (mean ± SD: age = 27.30 ± 2.06, body weight = 76.65 ± 12.50, body height = 176.9 ± 5.2) men at almost same ages and educational levels participated in this study. Cognitive functions were analyzed with mini-mental-state examination (MMSE) and Isaacs' Set Test of Verbal Fluency (IST) tests. Insulin-like growth factor-1 (IGF-1), BDNF and irisin levels were measured in the blood samples.

RESULTS

The MSSE and IST scores of the endurance athletes were higher than that of the sedentary control group (P < 0.05). Serum IGF-1 levels were higher in the pentathletes (111.18 ± 22.26 ng mL(-1)) than the orienteers (85.89 ± 19.32 ng mL(-1)) (P < 0.05). Plasma BDNF (2.78 ± 0.81, 4.28 ± 1.03, and 3.93 ± 0.77 ng mL(-1) in the sedentary, orienteers and pentathletes, respectively) and irisin (3.25 ± 0.70, 6.16 ± 0.99, and 6.58 ± 1.09 µg mL(-1) in the sedentary, orienteers and pentathletes, respectively) concentrations of the endurance trained athletes were higher than that of the sedentary control group (P < 0.05). Positive correlation between the cognitive function test results and BDNF and irisin concentrations were observed (P < 0.05). There was also a positive correlation between the circulating irisin and BDNF concentrations (P < 0.05).

CONCLUSION

These results suggested that irisin and BDNF levels positively correlated with cognition in the endurance trained athletes.

Levels of Serum Brain-Derived Neurotrophic Factor in Schizophrenia

Recent meta-analyses of serum brain-derived neurotrophic factor (BDNF) have reported lower levels in patients with schizophrenia. However, most studies did not consider the potential confounding effects of time of collection, age, sex, smoking, and obesity. Here, we sought to examine differences in serum BDNF between medicated patients with schizophrenia compared with control subjects, taking into consideration the potential confounders of serum BDNF. Serum was obtained from a sample of fasted blood collected from all participants, and BDNF was assayed on a commercially available kit. After adjusting for potential confounders, there was no statistically significant difference between cases and control subjects (p = 0.261). In the model, body mass index emerged as the most significant predictor of serum BDNF (β = 0.22, p = 0.009). The present study did not support a role for serum BDNF as a biomarker in schizophrenia. This could be due to the nonspecific nature of serum BDNF and its association with both mental and physical conditions.

Regulation of Energy Balance via BDNF Expressed in Nonparaventricular Hypothalamic Neurons

Brain-derived neurotrophic factor (BDNF) expressed in the paraventricular hypothalamus (PVH) has been shown to play a key role in regulating energy intake and energy expenditure. BDNF is also expressed in other hypothalamic nuclei; however, the role in the control of energy balance for BDNF produced in these structures remains largely unknown. We found that deleting the Bdnf gene in the ventromedial hypothalamus (VMH) during embryogenesis using the Sf1-Cre transgene had no effect on body weight in mice. In contrast, deleting the Bdnf gene in the adult VMH using Cre-expressing virus led to significant hyperphagia and obesity. These observations indicate that the lack of a hyperphagia phenotype in the Sf1-Cre/Bdnf mutant mice is likely due to developmental compensation. To investigate the role of BDNF expressed in other hypothalamic areas, we employed the hypothalamus-specific Nkx2.1-Cre transgene to delete the Bdnf gene. We found that the Nkx2.1-Cre transgene could abolish BDNF expression in many hypothalamic nuclei, but not in the PVH, and that the resulting mutant mice developed modest obesity due to reduced energy expenditure. Thus, BDNF produced in the VMH plays a role in regulating energy intake. Furthermore, BDNF expressed in hypothalamic areas other than PVH and VMH is also involved in the control of energy expenditure.

A method for reproducible measurements of serum BDNF: comparison of the performance of six commercial assays

Brain-Derived Neurotrophic Factor (BDNF) has attracted increasing interest as potential biomarker to support the diagnosis or monitor the efficacy of therapies in brain disorders. Circulating BDNF can be measured in serum, plasma or whole blood. However, the use of BDNF as biomarker is limited by the poor reproducibility of results, likely due to the variety of methods used for sample collection and BDNF analysis. To overcome these limitations, using sera from 40 healthy adults, we compared the performance of five ELISA kits (Aviscera-Bioscience, Biosensis, Millipore-ChemiKine^TM, Promega-Emax^®, R&D-System-Quantikine^®) and one multiplexing assay (Millipore-Milliplex^®). All kits showed 100% sample recovery and comparable range. However, they exhibited very different inter-assay variations from 5% to 20%. Inter-assay variations were higher than those declared by the manufacturers with only one exception which also had the best overall performance. Dot-blot analysis revealed that two kits selectively recognize mature BDNF, while the others reacted with both pro-BDNF and mature BDNF. In conclusion, we identified two assays to obtain reliable measurements of human serum BDNF, suitable for future clinical applications.

Genetic and epigenetic associations to obesity-related appetite phenotypes among African-American children

BACKGROUND

Genetic and epigenetic variations may be an important contributer to altered eating behaviors in childhood which may lead to weight gain and obesity later in life.

OBJECTIVE

This study aimed to evaluate epigenetic as well as genetic associations with appetite in young children.

SUBJECTS AND METHODS

Participants were 32 non-obese and 32 obese African-American children aged 5-6 years. Saliva was collected from each child, and RNA and DNA were extracted for analysis. Individuals were genotyped for eating- and obesity-associated single nucleotide polymorphisms in seven candidate genes (FTO, MAOA, SH2B1, LEPR, DNMT3B, BDNF and CCKAR), and DNA methylation levels were measured in the upstream promoter region of each. Transcript levels of MAOA and FTO were also assessed. The Children's Eating Behavior Questionnaire (CEBQ) was used to assess the aspects of appetite. Child obesity was assessed using measured height and weight, and percent body fat was measured by dual-energy X-ray absorptiometry.

RESULTS

Food responsiveness was higher and satiety responsiveness was lower among obese than non-obese female children (P = 0.001 and P = 0.031), but did not differ among male children. Epigenetic analysis of the BDNF promoter revealed associations with altered satiety responsiveness among female children (P < 0.01).

CONCLUSION

The findings provide new evidence of epigenetic associations with altered appetite among young African-American girls.

Serum Levels of Brain-Derived Neurotrophic Factor Are Associated with Diabetes Risk, Complications, and Obesity: a Cohort Study from Chinese Patients with Type 2 Diabetes

Brain-derived neurotrophic factor (BDNF) is associated with systemic inflammatory conditions, such as diabetes. The aim of this study was to assess the serum BDNF levels in Chinese patients with type 2 diabetes (T2DM). From the outpatient clinic at the endocrinology department of our hospital, all patients with long-standing T2DM were recruited for this study between August 2014 and December 2014. Serum levels of BDNF were assayed with solid-phase sandwich ELISA, and the demographical and clinical data were evaluated on admission. Median serum BDNF levels were significantly lower in patients with T2DM compared to control subjects (15.9 ng/mL (interquartile range (IQR), 12.6-19.8) VS. 24.6 ng/mL (IQR, 17.2-27.8); P < 0.0001). Serum BDNF levels were inversely correlated with fasting glucose (r = -0.394, P < 0.0001) and duration of illness (r = -0.272, P < 0.0001) in T2DM patients. Based on the receiver operating characteristic (ROC) curve, the optimal cutoff value of serum BDNF levels as an indicator for diagnosis of T2DM was projected to be 23.0 ng/mL, which yielded a sensitivity of 89.0 % and a specificity of 60.9 %, with the area under the curve at 0.794 (95 % confidence interval (CI), 0.747-0.841; P < 0.001). In multivariate logistic regression analysis, after adjusting for other significant factors, BDNF can be seen as an indicator of independent diabetes complications with an odds ratio (OR) of 0.84 (95 % CI, 0.75-0.89; P < 0.001) and obesity with an OR of 0.88 (95 % CI, 0.80-0.92; P < 0.001). Our study suggested that low levels of BDNF accompany impaired glucose metabolism. Importantly, we found that decreased BDNF were correlated with obesity and diabetes complications.

Higher BMI is associated with reduced brain volume in heart failure

Background

Heart failure (HF) patients are at risk for structural brain changes due to cerebral hypoperfusion. Past work shows obesity is linked with reduced cerebral blood flow and associated with brain atrophy in healthy individuals, although its effects on the brain in HF are unclear. This study examined the association among body mass index (BMI), cerebral perfusion, and brain volume in HF patients.

Results

Eighty HF patients underwent transcranial Doppler sonography to quantify cerebral blood flow velocity of the middle cerebral artery (CBF-V of the MCA) and brain magnetic resonance imaging (MRI) to quantify total brain, total and subcortical gray matter, white matter volume, and white matter hyperintensities. Body mass index (BMI) operationalized weight status. Nearly 45% of HF patients exhibited a BMI consistent with obesity. Regression analyses adjusting for medical variables, demographic characteristics, and CBF-V of the MCA, showed increased BMI was associated with reduced white matter volume (p < .05). BMI also interacted with cerebral perfusion to impact total gray matter volume, but this pattern did not emerge for any other MRI indices (p < 0.05).

Conclusions

Our findings suggest increased BMI negatively affects brain volume in HF, and higher BMI interacts with cerebral perfusion to impact gray matter volume. The mechanisms for these findings remain unclear and likely involve multiple physiological processes. Prospective studies are needed to elucidate the exact pattern and rates of brain changes in obese HF persons.

Changes in plasma Brain-derived neurotrophic factor (BDNF) levels induced by methylphenidate in children with Attention deficit-hyperactivity disorder (ADHD)

OBJECTIVES

It has been suggested that BDNF may play a role in the pathogenesis of ADHD. Our aim is to determine whether methylphenidate can induce changes in plasma BDNF levels of children with ADHD.

METHODS

We assessed levels of plasma BDNF in 28 ADHD patients (age range = 3.5-10 years) before and after 6 weeks treatment with effective dosages of methylphenidate. Then we evaluated the correlation of levels of plasma BDNF with clinical variables, especially ADHD Conner's parents rating scale.

RESULTS

According to the paired sample T-test, the mean plasma BDNF level in the baseline was 193.06 pg/ml, whereas 271.06 pg/ml in the end point, thus showing significantly higher mean plasma BDNF levels in the post-treatment situation than in the pretreatment (t = -3.393, df = 27, p = 0.002). Pearson's correlation test revealed that there was also significant negative correlation between levels of BDNF in the plasma of ADHD patients before treatment and improvement in hyperactivity symptoms with treatment (Pearson's correlation = -0.395, p = 0.037).

CONCLUSION

The mean plasma BDNF levels increased after 6 weeks of treatment with methylphenidate. Also, we found an improvement in hyperactivity symptoms with decreasing baseline plasma BDNF levels. We recommend that more studies should be conducted in order to assess the possible roles of plasma BDNF levels in treatment response prediction and prognosis.

On the quest for a biomechanism of transsexualism: is there a role for BDNF?

Previous studies hypothesized a neurobiological mechanism for gender identity disorder (GID). Recently a possible role for serum brain-derived neurotrophic factor (BDNF) was suggested on the basis of reduced serum BDNF levels in male-to-female individuals. Here we review the question whether there is indeed a role of BDNF in the development of transsexualism.

Brain-derived neurotrophic factor in human subjects with function-altering melanocortin-4 receptor variants

Background

In rodents, hypothalamic brain-derived neurotrophic factor (BDNF) expression appears to be regulated by melanocortin-4 receptor (MC4R) activity. The impact of MC4R genetic variation on circulating BDNF in humans is unknown.

Objective

To compare BDNF concentrations of subjects with loss-of-function (LOF) and gain-of-function (GOF) MC4R variants to those of controls with common sequence MC4R.

Methods

Circulating BDNF was measured in two cohorts with known MC4R sequence: 148 subjects of Pima Indian heritage ([mean±SD]: age 15.7±6.5y, BMI-Z 1.63±1.03), and 69 subjects of Hispanic heritage (10.8±3.6y, BMI-Z 1.57±1.07). MC4R variants were characterized in vitro by cell surface expression, receptor binding, and cAMP response after agonist administration. BDNF single nucleotide polymorphisms (SNPs) rs12291186, rs6265, and rs7124442 were also genotyped.

Results

In the Pima cohort, no significant differences in serum BDNF was observed for 43 LOF-subjects versus 65 LOF-matched controls [age-, sex-, and BMI-matched] (P=0.29), or 20 GOF-subjects versus 20 GOF-matched controls (P=0.40). Serum BDNF was significantly associated with genotype for BDNF rs12291186 (P=0.006) and rs6265 (P=0.009), but not rs7124442 (P=0.99); BDNF SNPs did not interact with MC4R status to predict serum BDNF. In the Hispanic cohort, plasma BDNF was not significantly different among 21 LOF-subjects, 20 GOF-subjects, and 28 controls (P=0.79); plasma BDNF was not predicted by BDNF genotype or BDNF-x-MC4R genotype interaction.

Conclusions

Circulating BDNF concentrations were not significantly associated with MC4R functional status, suggesting that peripheral BDNF does not directly reflect hypothalamic BDNF secretion and/or that MC4R signaling is not a significant regulator of the bulk of BDNF expression in humans.

Brain-derived neurotrophic factor expression ex vivo in obesity

Obesity is associated with an increased risk in neurodegenerative diseases. To counteract the neuronal damage, the human body increases brain-derived neurotrophic factor (BDNF) expression, leading to neuronal survival and plasticity. Recently, peripheral blood mononuclear cells (PBMCs) have been found to release BDNF as a potential neuroprotective role of inflammation. Therefore, the purpose of this study was to examine whether lipopolysaccharide (LPS)-induced PBMC activation would lead to differences in BDNF and inflammatory responses between obese and non-obese subjects. Thirty-one subjects (14 obese and 17 non-obese), ages 18 to 30years, were recruited. PBMCs were cultured for 24h with 10ng/mL LPS. BDNF, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured in both plasma and cell culture supernatants. Our results did not illustrate any differences in plasma BDNF levels between obese and non-obese groups. However, obese subjects elicited a greater plasma IL-6 production, which was positively associated with plasma BDNF. Furthermore, LPS-induced PBMCs expressed significantly higher BDNF and IL-6 levels in obese subjects compared to the non-obese subjects. Finally, these BDNF levels were positively correlated with IL-6 response ex vivo. These findings suggest that under a high inflammatory state, PBMCs produce greater BDNF and IL-6 expression which may play a collaborative role to protect against neuronal damage associated with obesity.

Lifestyle modification and behavior therapy effectively reduce body weight and increase serum level of brain-derived neurotrophic factor in obese non-diabetic patients with schizophrenia

The goal of the study was to elucidate the relationship between serum circulating brain-derived neurotrophic factor (BDNF) and body weight reduction via lifestyle modification and behavior therapy in obese non-diabetic patients with chronic schizophrenia. Thirty-three obese non-diabetic subjects with schizophrenia treated with stable antipsychotic medication in a day-care unit for at least 3 months were recruited. Thirty age-, body weight-matched subjects without psychiatric disorders were enrolled as controls. All participants underwent a 10-week weight reduction program, including lifestyle modification, psychosocial treatment, behavior therapy and exercise in the day-care unit. Blood biochemistry, serum BDNF, adipokine (adiponectin), inflammatory markers (C-reactive protein, tumor necrosis factor-alpha and interleukin-6) and oral glucose tolerance test were evaluated before and after the program. Serum BDNF concentrations were significantly lower among patients with schizophrenia compared to control subjects. Serum BDNF levels were significantly increased following the weight reduction program. Elevations in serum BDNF levels were positively correlated with body weight and body mass index reduction. Altogether, our results demonstrate that a non-pharmacological weight reduction program effectively reduces body weight with significant elevation of serum BDNF levels in obese non-diabetic patients with schizophrenia.

The skinny on brain-derived neurotrophic factor: evidence from animal models to GWAS

Obesity and its sequelae constitute a major international healthcare problem. The obesity epidemic is due in part to higher calorie diets and reduced exercise over the past 30 years; however, increasing evidence has established genetic regulation of body weight as a major contributor to obesity. Brain-derived neurotrophic factor (BDNF) regulates development and plasticity of the central nervous system, and recent work has established a clear role for signaling through BDNF and its receptor TrkB in the control of body weight. Here we review research findings from animal models and human populations indicating that BDNF is a negative regulator of appetitive behavior and body weight.