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

The association between levels of brain-derived neurotrophic factor and comorbid depression in patients with cardiovascular disease: The Framingham Heart Study

AIM

The current study aims to investigate the association of serum brain-derived neurotrophic factor (BDNF) levels with symptoms of depression in adults with and without prevalent cardiovascular disease (CVD), an often burdensome comorbidity.

METHODS

This cross-sectional study included participants from FHS (Framingham Heart Study) who had available serum BDNF levels. Depressive symptoms were assessed using the Center for Epidemiological Studies-Depression Scale (CES-D) with a score ≥16 indicating mild to moderate and ≥21 severe depression. Participants taking antidepressant medications were excluded from the study.

RESULTS

Altogether 3716 FHS participants were included in the final analysis (mean age, 64.3 ± 11.5 years; 55% women). After adjusting for potential confounders, greater BDNF levels were associated with reduced severe depression risk (odds ratio [OR], 0.78 [95% CI, 0.64-0.96]; P = 0.016). Among participants with CVD, greater BDNF levels were related to lower risk of depressive symptoms (CES-D ≥ 16 OR, 0.63 [95% CI, 0.45-0.89], P = 0.008; CES-D ≥ 21 OR, 0.49 [95% CI, 0.31-0.76], P = 0.002). The inverse relationship between BDNF and depressive symptom risk was present in women with CVD (CES-D ≥ 16 OR, 0.63 [95% CI, 0.40-0.99], P = 0.047; CES-D ≥ 21 OR, 0.38 [95% CI, 0.21-0.70], P = 0.002) but not in men.

CONCLUSION

Lower serum BDNF levels are associated with a higher risk of depressive symptoms in CVD, particularly among women. These findings implicate BDNF in the complex biological mechanisms that underlie prior associations observed between CVD and depression. To reduce the burden of depression in the large proportion of midlife and older adults with CVD, a better understanding of how BDNF may modify these pathways is merited.

Somatization is associated with altered serum levels of vitamin D, serotonin, and brain-derived neurotrophic factor in patients with predominant diarrhea irritable bowel syndrome

BACKGROUND

Patients with irritable bowel syndrome (IBS) often show psychological disorders, including somatization, usually driven by an altered gut-brain axis. These changes are also accompanied by modifications in the circulating levels of vitamin D (VD) and neurotransmitters such as serotonin (5-HT) and brain-derived neurotrophic factor (BDNF). The present study aimed to evaluate the relationship between gastrointestinal (GI) symptoms and circulating levels of VD, 5-HT, and BDNF in IBS patients with diarrhea (IBS-D) categorized according to somatization.

METHODS

Fifty-three IBS-D patients were recruited and profiled for GI symptoms by validated questionnaires. The fasting serum concentrations of VD, 5-HT, and BDNF were assessed. The health of the intestinal barrier, minimal inflammation, and dysbiosis was also evaluated.

KEY RESULTS

Thirty patients showed high somatization scores, IBS-D(S+), and 23 low somatization scores, IBS-D(S-). IBS-D(S+) patients reported higher "Abdominal pain" and the "Abdominal pain duration in days" scores, lower serum VD levels and increased 5-HT and BDNF concentrations than IBS-D(S-). Besides, in IBS-D(S+) patients, the GI symptoms correlated with 5HT, BDNF, and VD concentrations. These parameters were associated with impaired small intestinal permeability and increased inflammation markers.

CONCLUSIONS AND INFERENCES

These data support the multifactorial IBS pathogenesis in which organic and psychological factors interact. An active role by VD, 5-HT, and BDNF in affecting the clinical and biochemical profiles in IBS-D(S+) patients may be conceivable. Therefore, the routine VD estimation and the assay of circulating levels of 5-HT and BDNF could be considered a new approach for managing these patients.

The association between vitamin D and BDNF on cognition in older adults in Southern Brazil

OBJECTIVE

To estimate the association between vitamin D and the cognitive decline of older adults and evaluate whether this association is mediated by brain-derived neurotrophic factor (BDNF) serum concentration.

METHODS

Cross-sectional study nested in a population-based cohort. Of the 604 participants in the complementary examination of the EpiFloripa Study, 576 older adults (60 years or older) were eligible for the study. The outcome is cognitive decline evaluated by the Mini-Mental State Examination, the exposure is vitamin D, and BDNF is the mediator. The control variables are age, sex, per capita family income, and educational level. The direct effect of vitamin D and BDNF on cognitive decline and the indirect effect mediated by BDNF was evaluated using path analysis, with the estimation of standardized coefficients.

RESULTS

Among the participants, we observed a direct and positive effect of vitamin D on cognitive function (Coef: 0.06; 95%CI: 0.02 to 0.11; p < 0.001) and serum BDNF concentration (Coef: 21.55; 95%CI: 9.92 to 33.17; p = 0.002), i.e., the higher the vitamin D, the higher the cognitive function and serum level of BDNF.

CONCLUSION

There was an association between vitamin D on serum BDNF and on cognitive decline in older adults. Moreover, BDNF did not have an effect on cognitive decline, so BDNF was not a mediator of the vitamin D effect on cognitive decline.

Exercise-Induced Adipose Tissue Thermogenesis and Browning: How to Explain the Conflicting Findings?

Brown adipose tissue (BAT) has been widely studied in targeting against metabolic diseases such as obesity, type 2 diabetes and insulin resistance due to its role in nutrient metabolism and energy regulation. Whether exercise promotes adipose tissue thermogenesis and browning remains controversial. The results from human and rodent studies contradict each other. In our opinion, fat thermogenesis or browning promoted by exercise should not be a biomarker of health benefits, but an adaptation under the stress between body temperature regulation and energy supply and expenditure of multiple organs. In this review, we discuss some factors that may contribute to conflicting experimental results, such as different thermoneutral zones, gender, training experience and the heterogeneity of fat depots. In addition, we explain that a redox state in cells potentially causes thermogenesis heterogeneity and different oxidation states of UCP1, which has led to the discrepancies noted in previous studies. We describe a network by which exercise orchestrates the browning and thermogenesis of adipose tissue with total energy expenditure through multiple organs (muscle, brain, liver and adipose tissue) and multiple pathways (nerve, endocrine and metabolic products), providing a possible interpretation for the conflicting findings.

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.

Association between Serum Brain-derived Neurotrophic Factor and 25-OH Vitamin D Levels with Vitamin D Receptors Gene Polymorphism (rs2228570) in Patients with Autoimmune Thyroiditis and Hypothyroidism

BACKGROUND: Different polymorphisms in Vitamin D receptors (VDRs) have an important role in autoimmune thyroiditis (AIT) risk. Hashimoto’s thyroiditis (HT) is the most recurrent autoimmune thyroid disorder. Patients with HT may suffer from cognitive impairment brain-derived neurotrophic factor (BDNF) which has been identified as an important growth factor that is involved in learning and memory. AIM: This study examined the linkage of VDR gene polymorphism (rs2228570) with blood serum levels of BDNF and 25-OH Vitamin D in thyroid pathology of patients in the West Ukrainian population. METHODS: This research is a case–control study was performed in HSEEU “Bukovinian State Medical University,” Chernivtsi Regional Endocrinology Center, and I. Horbachevsky Ternopil National Medical University, Ukraine, from September 2017 to December 2020. The study involved a total of 153 patients with post-operative hypothyroidism, hypothyroidism induced by AIT, and patients with both AIT and elevated serum antibodies anti-thyroglobulin (anti-Tg) and anti-thyroid peroxidase. BDNF levels in the sera of the patients and healthy individuals were quantified using enzyme-linked immunosorbent assay (ELISA) with highly sensitive Human BDNF ELISA Kit. Genotyping of the VDR (rs2228570) gene polymorphism using TaqMan probes and TaqMan Genotyping Master Mix (4371355) on CFX96™ Real-Time Polymerase Chain Reaction (PCR) Detection System (Bio-Rad Laboratories, Inc., USA). PCR for TaqMan genotyping was carried out according to the kit instructions (Applied Biosystems, USA). RESULTS: Our study revealed a significant decrease in the BDNF level in the study group in carriers of the AA and AG genotypes by 1.58 and 2.39 times, corresponding, compared with carriers of the AA genotype in the control group. Concurrently, there was no significant difference in the BDNF level between different genotypes of VDR rs2228570 in the research group. In our study, analysis of the correlation between serum BDNF levels and 25-OH Vitamin D concentration shows a moderate direct relationship (r = 0.4) between BDNF and 25-OH Vitamin D (p = 0.006). CONCLUSIONS: The rs2228570 VDR polymorphism is not a risk factor for decreased serum BDNF levels. At the same time, our study found a moderate direct relationship between serum BDNF levels and 25-OH Vitamin D.

Randomized study of the effects of vitamin D and/or magnesium supplementation on mood, serum levels of BDNF, inflammation, and SIRT1 in obese women with mild to moderate depressive symptoms

OBJECTIVES

This study aimed to evaluate the effects of vitamin D and/or magnesium supplementation on mood, serum levels of BDNF, inflammation, and SIRT1 in obese women with mild to moderate depressive symptoms.

METHODS

In this trial, the 108 obese women with mild to moderate depressive symptoms were randomly allocated into 4 groups: (1) co- supplementation group (n = 27): receiving a 50000 IU vitamin D soft gel weekly + a 250- mg magnesium tablet daily; (2) vitamin D group (n = 27): receiving a 50000 IU vitamin D soft gel weekly + a magnesium placebo daily; (3) magnesium group (n = 27): receiving a vitamin D placebo weekly + a 250- mg magnesium tablet daily; (4) control group (n = 27): receiving a vitamin D placebo weekly + a magnesium placebo daily, for 8 weeks. Before and after the intervention, anthropometric indices, depressive symptoms, serum levels of BDNF, 25(OH)-D, inflammation, and SIRT1, were measured.

RESULTS

At the end of the study, ANCOVA demonstrated significant differences between the 4 groups in 25(OH)-D, magnesium, TNF-α, IL-6, and BDNF levels. But, we found no significant differences in terms of hs-CRP and SIRT1 levels. A significant reduction in depression score was observed in 3 intervention groups and also in control group. No significant differences in BDI-II score were shown among the 4 groups at the end of the intervention.

CONCLUSION

Vitamin D plus magnesium supplementation in obese women with mild to moderate depressive symptoms has beneficial influences on mood, serum levels of BDNF, inflammation, and SIRT1.

Similarities and Differences of Mental Health in Women and Men: A Systematic Review of Findings in Three Large German Cohorts

In Germany, large, population-based cohort studies have been implemented in order to identify risk and protective factors for maintaining health across the life span. The purpose of this systematic review is to analyse findings from three large ongoing cohorts and to identify sex-specific prevalence rates, risk and protective factors for mental health. Published studies from the Cooperative Health Research in the Region Augsburg (KORA), the Study of Health in Pomerania (SHIP) and the Gutenberg Health Study (GHS)), representing the southern, north-eastern and middle parts of Germany, were identified through searches of the databases PubMed and Web of Science. A total of 52 articles was identified from the start of each cohort until June 2019. Articles reporting prevalence rates of mental health [N = 22], explanatory factors for mental health [N = 25], or both [N = 5] were identified. Consistent across cohorts, higher prevalence rates of internalizing disorders were found for women and more externalizing disorders for men. Risk and protective factors for mental health included social factors, lifestyle, physical health, body mass index (BMI), diabetes, genetic and biological factors. In all areas, differences and similarities were found between women and men. The most evident were the sex-specific risk profiles for depression with mostly external risk factors for men and internal risk factors for women. Gender was not assessed directly, therefore we examined whether socioeconomic and family-related factors reflecting gender roles or institutionalized gender could be used as a proxy for gender. Overall, this systematic review shows differences and similarities in prevalence rates and determinants of mental health indicators between women and men. They underline the importance of focussing on sex specific approaches in mental health research and in the development of prevention measures. Current research on mental health still lacks focus on gender aspects. Therefore, an increased focus on sex and gender in mental health research is of great importance.

Vitamin D moderates the interaction between 5-HTTLPR and childhood abuse in depressive disorders

A complex interplay between genetic and environmental factors determines the individual risk of depressive disorders. Vitamin D has been shown to stimulate the expression of the tryptophan hydroxylase 2 (TPH2) gene, which is the rate-limiting enzyme for serotonin production in the brain. Therefore, we investigate the hypothesis that serum vitamin D levels moderate the interaction between the serotonin transporter promotor gene polymorphism (5-HTTLPR) and childhood abuse in depressive disorders. Two independent samples from the Study of Health in Pomerania (SHIP-LEGEND: n = 1 997; SHIP-TREND-0: n = 2 939) were used. Depressive disorders were assessed using questionnaires (BDI-II, PHQ-9) and interview procedures (DSM-IV). Besides serum vitamin D levels (25(OH)D), a functional polymorphism (rs4588) of the vitamin D-binding protein is used as a proxy for 25(OH)D. S-allele carriers with childhood abuse and low 25(OH)D levels have a higher mean BDI-II score (13.25) than those with a higher 25(OH)D level (9.56), which was not observed in abused LL-carriers. This significant three-way interaction was replicated in individuals with lifetime major depressive disorders when using the rs4588 instead of 25(OH)D (p = 0.0076 in the combined sample). We conclude that vitamin D relevantly moderates the interaction between childhood abuse and the serotonergic system, thereby impacting vulnerability to depressive disorders.

Role of Adiponectin and Brain Derived Neurotrophic Factor in Metabolic Regulation Involved in Adiposity and Body Fat Browning

Obesity, characterized by excessive fat mass, has been emerging as a major global epidemic and contributes to the increased risk of morbidity around the world. Thus, the necessity to find effective therapy and specific regulatory mechanisms is increasing for controlling obesity. Lately, many researchers have been interested in the linkage between obesity and adipokines/myokines, particularly adiponectin and brain-derived neurotrophic factor (BDNF). However, the role of adiponectin and BDNF in adiposity has not been clearly defined yet. We examined the association of adiposity with adiponectin and BDNF through human study (observational study) with Korean women and in vitro experiments. In the human study, we found a negative relationship between adiposity and circulating adiponectins but irregular patterns in the relationship between adiposity and circulating BDNFs. In the in vitro study using 3T3-L1 adipocytes, adiponectin treatment strongly promoted adipocyte differentiation and the fat browning process, whereas BDNF treatment attenuated adipocyte differentiation and the fat browning process in differentiated adipocytes. Our results demonstrate that adiponectin and BDNF play an important role in regulating fat mass and the expression of fat-browning markers in different ways, and also suggest that circulating adiponectin may be used as an important monitoring index for obesity status.

Vitamin D levels are associated with trait resilience but not depression in a general population sample

INTRODUCTION

Insufficient vitamin D levels were found to be related to various psychiatric disorders and particularly depression. The functional polymorphisms rs4588 and rs7041 of the vitamin D-binding protein (also group-specific component or Gc) influence vitamin D level and activity. Resilience is considered the individual predisposition to maintain psychological functioning in the face of adversities. We sought to investigate whether associations of vitamin D levels and genotypes of rs4588 and rs7041 were associated with trait resilience and symptoms of depression.

METHODS

Serum levels of total 25(OH)D were measured in a general population sample (n = 1,908) of the Study of Health in Pomerania (SHIP-1). The Resilience Scale-25 (RS-25) was applied to assess trait resilience. Lifetime depressive symptoms were assessed using the CID-S, while current depressive symptoms were measured using the Beck Depression Inventory II (BDI-II). Study participants were genotyped for rs4588 and rs7041.

RESULTS

Participants with vitamin D insufficiency had lower adjusted mean RS-25 scores as compared to vitamin D replete subjects (p = .002). Linear regression analyses revealed a positive association between 25(OH)D and RS-25 scores (ß = 2.782, p = .002). Additional adjustment for BDI-II scores slightly attenuated this result (ß = 1.830 and p = .026). Symptoms of depression and the lifetime diagnosis of MDD were not significantly associated with vitamin D concentrations. rs4588 and rs7041 showed strong associations with vitamin D concentrations (both p < .001), but not RS-25 scores.

CONCLUSIONS

In contrast with previous studies, our findings do not provide evidence for a strong role of vitamin D in the psychopathology of depression. However, considering the role of trait resilience as a common protective factor to different psychiatric disorders, our results support the concept of low vitamin D as a general risk factor to stress-related psychopathologies.

Effects of vitamin D and/or magnesium supplementation on mood, serum levels of BDNF, inflammatory biomarkers, and SIRT1 in obese women: a study protocol for a double-blind, randomized, placebo-controlled trial

Background

Emerging evidence has shown that vitamin D and magnesium have anti-inflammatory and anti-depressant effects. Dietary intake of magnesium is associated with reduced body mass index, waist circumference, body fat percentage, as well as inflammatory biomarkers and depressive symptoms. Vitamin D deficiency has been linked to inflammation, obesity, and depressive symptoms. This study will test the effects of vitamin D and magnesium co-supplementation on mood, serum level of brain-derived neurotrophic factor (BDNF), inflammation, and sirtuin 1 (SIRT1) in obese women.

Methods

We will conduct an 8-week, double-blind, randomized, placebo-controlled clinical trial, in a factorial design, to evaluate the individual effects of vitamin D and magnesium, and co-supplementation of them, on mood, serum level of BDNF, inflammation, and SIRT1 in 108 obese women.

Discussion

We hypothesize that vitamin D and magnesium co-supplementation may provide a new adjuvant therapy through modulation of BDNF, inflammation, and SIRT1 in obese women.

Trial registration

Iranian Registry of Clinical Trials, IRCT20090822002365N23. Registered on 16 August 2019.

Posttraumatic stress disorder is associated with reduced vitamin D levels and functional polymorphisms of the vitamin D binding-protein in a population-based sample

OBJECTIVE

Low levels of vitamin D were found to be associated with different mental disorders. However, the role of vitamin D in the pathogenesis of PTSD is unclear. In this study, we aimed at investigating whether PTSD is linked to reduced vitamin D levels and vitamin D deficiency. Moreover, we sought to investigate the role of the vitamin D-binding protein (also group-specific component or Gc) by testing if two functional polymorphisms (rs4588 and rs7041) were associated with vitamin D levels and PTSD.

METHODS

Serum levels of total 25(OH)D were measured in a general-population sample of the Study of Health in Pomerania (SHIP-1). The number of traumatic events and status of PTSD were assessed using the PTSD module of the Structured Clinical Interview for the DSM-IV. Study participants were genotyped for rs4588 and rs7041. Associations of 25(OH)D levels and the genotypes with PTSD were tested in subjects with at least one traumatic event (n = 1653).

RESULTS

25(OH)D levels were inversely (OR: 0.96; p = 0.044) and vitamin D deficiency was positively (OR = 2.02; p = 0.028) associated with PTSD. Both polymorphisms of the Gc were associated with 25(OH)D levels and PTSD: Carriers of the CC-genotype of rs4588 showed significantly higher 25(OH)D levels (ß = 0.179, p < 0.001) and lower odds for PTSD (OR = 0.35; p = 0.023) compared to the AA-genotype. Likewise, carriers of the TT-allele of rs7041 showed lower 25(OH)D levels (-0.122; p < 0.001) and increased odds for PTSD (OR = 2.80; p = 0.015) compared to the GG-genotype.

CONCLUSIONS

Our results suggest that an altered vitamin D metabolism may be involved in the pathophysiology of PTSD. Also, genotypes of the Gc and thus Gc serum levels may impact on PTSD development over and above the effects of 25(OH)D. Our findings contribute to explain the associations of PTSD with different mental and physical disorders.

Non-Phosphorylated Tau in Cerebrospinal Fluid is a Marker of Alzheimer's Disease Continuum in Young Urbanites Exposed to Air Pollution

Long-term exposure to fine particulate matter (PM2.5) and ozone (O3) above USEPA standards is associated with Alzheimer's disease (AD) risk. Metropolitan Mexico City (MMC) children exhibit subcortical pretangles in infancy and cortical tau pre-tangles, NFTs, and amyloid phases 1-2 by the 2nd decade. Given their AD continuum, we measured in 507 normal cerebrospinal fluid (CSF) samples (MMC 354, controls 153, 12.82±6.73 y), a high affinity monoclonal non-phosphorylated tau antibody (non-P-Tau), as a potential biomarker of AD and axonal damage. In 81 samples, we also measured total tau (T-Tau), tau phosphorylated at threonine 181 (P-Tau), amyloid-β1-42, BDNF, and vitamin D. We documented by electron microscopy myelinated axonal size and the pathology associated with combustion-derived nanoparticles (CDNPs) in anterior cingulate cortex white matter in 6 young residents (16.25±3.34 y). Non-P-Tau showed a strong increase with age significantly faster among MMC versus controls (p = 0.0055). Aβ1 - 42 and BDNF concentrations were lower in MMC children (p = 0.002 and 0.03, respectively). Anterior cingulate cortex showed a significant decrease (p = <0.0001) in the average axonal size and CDNPs were associated with organelle pathology. Significant age increases in non-P-Tau support tau changes early in a population with axonal pathology and evolving AD hallmarks in the first two decades of life. Non-P-Tau is an early biomarker of axonal damage and potentially valuable to monitor progressive longitudinal changes along with AD multianalyte classical CSF markers. Neuroprotection of young urbanites with PM2.5 and CDNPs exposures ought to be a public health priority to halt the development of AD in the first two decades of life.

Brain-derived neurotrophic factor is related with adverse cardiac remodeling and high NTproBNP

The brain-derived neurotrophic factor (BDNF) is a neuronal growth factor essential for normal cardiac contraction and relaxation. Alterations in BDNF signaling are related to the development of cardiovascular disease. Whether BDNF is related to subclinical cardiac remodeling is unclear. We related BDNF with echocardiographic parameters and NTproBNP in a large population-based cohort (n = 2,976, median age 48 years; 45% male). Transthoracic echocardiography was performed on all subjects and BDNF was measured by ELISA. Study participants with severe kidney dysfunction, previous myocardial infarction, and LV ejection fraction <40% were excluded. Linear regression models were adjusted for age, sex, lean mass, fat mass, current smoking, systolic blood pressure and depression. Low BDNF was associated with high NTproBNP. A 10,000 pg/ml lower BDNF was related with a 2.5 g higher (95%-confidence interval [CI]: 0.2 to 4.9; p = 0.036) LV mass, 0.01 cm posterior wall thickness (0.003 to 0.022; p = 0.007) and 0.02 E/A ratio (0.003 to 0.042, p = 0.026). Here we show that low BDNF levels are related with adverse cardiac remodeling and higher levels of NTproBNP. Further research is warranted to assess if BDNF may be used to monitor neuronal-cardiac damage during CVD progression.

Sex-Specific Associations of Brain-Derived Neurotrophic Factor and Cardiorespiratory Fitness in the General Population

The brain-derived neurotrophic factor (BDNF) was initially considered to be neuron-specific. Meanwhile, this neurotrophin is peripherally also secreted by skeletal muscle cells and increases due to exercise. Whether BDNF is related to cardiorespiratory fitness (CRF) is currently unclear. We analyzed the association of serum BDNF levels with CRF in the general population (Study of Health in Pomerania (SHIP-TREND) from Northeast Germany; n = 1607, 51% female; median age 48 years). Sex-stratified linear regression models adjusted for age, height, smoking, body fat, lean mass, physical activity, and depression analyzed the association between BDNF and maximal oxygen consumption (VO₂peak), maximal oxygen consumption normalized for body weight (VO₂peak/kg), and oxygen consumption at the anaerobic threshold (VO₂@AT). In women, 1 mL/min higher VO₂peak, VO₂peak/kg, and VO₂@AT were associated with a 2.43 pg/mL (95% confidence interval [CI]: 1.16 to 3.69 pg/mL; p = 0.0002), 150.66 pg/mL (95% CI: 63.42 to 237.90 pg/mL; p = 0.0007), and 2.68 pg/mL (95% CI: 0.5 to 4.8 pg/mL; p = 0.01) higher BDNF serum concentration, respectively. No significant associations were found in men. Further research is needed to understand the sex-specific association between CRF and BDNF.

Sunlight radiation as a villain and hero: 60 years of illuminating research

In the 60 years since the inaugural edition of the International Journal of Radiation Biology, much of our understanding of the biological effects of solar radiation has changed. Earlier in the century, sunlight played a 'hero's' role in reducing disabling rickets, while today debate still continues on the amount of sun required before exposure reveals the 'villainous' side of solar radiation. Although knowledge of the ultra violet (UV) component of sunlight as a carcinogen has become widespread, skin cancer rates are still rising yearly. Twentieth century attitudes have seen an about-face in the field of dermatological sun protection, with sunscreens changing from recipes designed to promote a 'healthy tan' to formulations proven to block both ultraviolet B (UVB) and more recently, ultraviolet A (UVA), to minimize premature sun-aging and skin cancer risk. In the early 1960s, DNA was first found to exist within mitochondria, while recently the connections between mitochondrial changes and UV radiation exposure have been expanded. Sixty years ago, understanding of the endocrine systems of mammals was enjoying its infancy. Early discoveries that light, particularly natural light, could have profound effects on functions such as sleep patterns and hormonal balance were made, while today more advanced knowledge has led to lighting improvements having pronounced effects on human wellbeing. Photosensitization 60 years ago was a health concern for both humans and their domestic animals, while today chemically engineered photosensitizing drugs can be administered along with highly directed light to pinpoint delivery targets for drug action. Life on earth is inextricably bound up with solar radiation. This article attempts to outline many of the ways in which our opinions about solar radiation have changed since the journal's inception.

Hericium erinaceus Improves Mood and Sleep Disorders in Patients Affected by Overweight or Obesity: Could Circulating Pro-BDNF and BDNF Be Potential Biomarkers?

Epidemiological data indicate that subjects affected by obesity have an increased risk of developing mood disorders. The relationship between obesity and mood disorders is bidirectional. We assessed whether a Hericium erinaceus treatment improved depression, anxiety, sleep, and binge eating disorders after 8 weeks of supplementation in subjects affected by overweight or obesity under a low calorie diet regimen. Looking for a possible clinical biomarker, we assessed the serum balance between brain-derived neurotrophic factor (BDNF) and its precursor pro-BDNF before and after H. erinaceus supplementation. Seventy-seven volunteers affected by overweight or obesity were recruited at the offices of the Department of Preventive Medicine, Luigi Devoto Clinic of Work, Obesity Centre, at the IRCCS Foundation Policlinico Hospital of Milan (Italy). Patients were recruited only if they had a mood and/or sleep disorder and/or were binge eating as evaluated through self-assessment questionnaires. We used two different enzyme-linked immunosorbent assays kits to discriminate circulating levels of pro-BDNF and BDNF. Eight weeks of oral H. erinaceus supplementation decreased depression, anxiety, and sleep disorders. H. erinaceus supplementation improved mood disorders of a depressive-anxious nature and the quality of the nocturnal rest. H. erinaceus increased circulating pro-BDNF levels without any significant change in BDNF circulating levels.

Demographic and lifestyle correlates of brain-derived neurotrophic factor in a working population: The Furukawa Nutrition and Health Study

This study aimed to examine the cross-sectional association of demographic and lifestyle factors with serum brain-derived neurotrophic factor (BDNF) concentrations in a Japanese working population. Participants were 1678 men and 172 women aged 19-69 years who received health check-ups and participated in a nutrition and health survey. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Dietary intake was assessed using a validated self-administered diet history questionnaire. Serum BDNF concentrations were measured using a solid phase sandwich enzyme-linked immunosorbent assay. Multiple linear regression analysis was used to estimate the mean and 95% confidence interval of serum BDNF concentrations according to demographic and lifestyle factors. Higher body mass index (BMI) was significantly associated with higher circulating BDNF concentrations. Current smokers had significantly higher mean BDNF concentrations than never-smokers. BDNF concentrations were not associated with folate and 25-hydroxyvitamin D concentrations in serum, or dietary eicosapentaenoic acid and docosahexaenoic acid intake. Serum BDNF concentrations were not associated with depressive symptoms or CES-D score per se. In this study, higher BMI and smoking were associated with higher concentrations of serum BDNF, while nutrients that have been linked to depression were not associated with BDNF concentrations among Japanese workers.