Associations of fatty acids with cognition, psychopathology, and brain-derived neurotrophic factor levels in patients with first-episode schizophrenia and related disorders treated with paliperidone extended release

Association between reduced plasma BDNF concentration and MMSE scores in both chronic schizophrenia and mild cognitive impairment

Reduced brain derived neurotrophic factor (BDNF) concentration is reported to be associated with a cognitive decline in schizophrenia, depending on the stage of the disease. Aim of the study was to examine the possible association between plasma BDNF and cognitive decline in chronic stable schizophrenia and mild cognitive impairment (MCI). The study included 123 inpatients of both sexes with schizophrenia, 123 patients with MCI and 208 healthy control subjects. Cognitive abilities were assessed using mini mental state examination (MMSE), Clock Drawing test (CDT) and cognitive subscale of the Positive and Negative Syndrome Scale (PANSS). Plasma BDNF concentration was determined using ELISA. BDNF concentration was lower in patients with schizophrenia and MCI compared to age-matched healthy controls and was similar in carriers of different BDNF Val/66Met genotypes. The MMSE and CDT scores were lower in patients with schizophrenia compared to healthy controls and subjects with MCI. Reduced plasma BDNF was significantly associated with lower MMSE scores in all subjects. BDNF concentration in patients with schizophrenia was not affected by clinical and demographic factors. BDNF Val66Met polymorphism was not associated with the MMSE scores in all participants. Further studies should include longitudinal follow-up and other cognitive scales to confirm these results and offer cognition-improving strategies to prevent cognitive decline in chronic schizophrenia.

Correlation of the Serum Fatty Acids with Cognitive Function: An NHANES 2011-2014 and Multivariate Mendelian Randomization Analysis

Background

The relationship between serum fatty acids and cognitive function has been the subject of extensive study.

Objective

To analyze the relationship between serum fatty acids composition and cognitive function by NHANES database and multivariate Mendelian randomization (MR) analysis.

Methods

A sub-cohort of 1,339 individuals with serum fatty acids and Digit Symbol Substitution Test (DSST) examinations from the 2011-2014 wave of the NHANES were analyzed using fully adjusted multiple linear regression models for associations between serum hydrolyzed fatty acid levels and cognitive function. Univariable and multivariable MR was used to analyze the correlation between 98 exposures related to serum fatty acids and cognitive function. Results from different database sources were combined using meta-analysis.

Results

The fully adjusted regression analysis showed that linoleic acid (LA), Omega 6, fatty acids (FAs), and LA/FAs were positively correlated with DSST. 27 exposures were included for univariate MR analysis. Ultimately, only 2 traits had IVW test p-values ranging between 0.0019 and 0.05, both of which were LA/FAs. The meta-analysis of univariate MR revealed that LA/FAs was positively associated with cognitive function (β: 0.040, 95% CI = 0.013-0.067, p = 0.0041). In multivariate MR analysis, after adjusting for education, ischemic stroke, and age, LA/FAs was positively independently associated with cognitive function (IVW β: 0.049, 95% CI = 0.021-0.077, p = 0.0006). The results of MVMR are well in line with the univariate results.

Conclusions

Both the Cross-sectional observational analyses and MR-based studies supported a suggestive causal relationship between the serum ratio of Linoleic acid in fatty acids and cognitive function.

The Effects of Treatment in Psychotic Disorders-Changes in BDNF Levels and Clinical Outcomes: Systematic Review

Psychotic disorders are associated with significant impairment in functioning, and their treatment remains a great therapeutic challenge. Patients are at a higher risk of suicide and premature mortality. Biomarkers, such as brain-derived neurotrophic factor (BDNF), play a vital role in neurotransmission and neurodevelopment. Decreased levels of BDNF alter neuronal signaling and cause the appearance of symptoms such as the impairment of working memory. A literature search was performed using the PubMed data base. Following the inclusion and exclusion criteria, 24 original articles were selected. We collected available data showcasing the influence of antipsychotic and non-pharmacological treatments, in patients suffering from psychotic disorders, on clinical conditions and BDNF levels in serum or plasma. In this review, we outline emerging data regarding the influence of different antipsychotic drugs and non-pharmacological treatment methods on BDNF and discuss their role as predictors of treatment outcome. Most studies conducted with antipsychotics saw an increase in BDNF levels; however, no positive correlation between change in BDNF and PANSS scores was observed. Studies based on non-pharmacological methods varied based on the treatment applied. Therefore, it is difficult to draw definite conclusions.

Peripheral Blood Levels of Brain-Derived Neurotrophic Factor in Patients with First Episode Psychosis: A Systematic Review and Meta-Analysis

Background: Peripheral blood level of brain-derived neurotrophic factor (BDNF) may be used as a diagnostic and/or prognostic marker for schizophrenia. Previous studies were inconsistent. A systematic review was conducted to examine whether BDNF level is different in patients with first episode psychosis (FEP) compared to health controls (HC) and whether it changes after treatment. Methods: Literature search was done in PubMed, Web of Science, and Google Scholar following standard procedures. Hedges’ g was used as the measure of effect size (ES), which was pooled with random effects model. Publication bias and moderator effects were examined. Results: Search yielded 29 studies with a total sample size of 2912. First meta-analysis included 27 studies with FEP vs. HC comparison. Pooled ES was −0.63, p < 0.001, indicating that BDNF level was lower in FEP than in HC. Studies were heterogeneous, and moderator analysis showed that studies of younger patient, higher symptom severity, and more drug naïve had larger ES. Second meta-analysis examined change in BDNF levels before and after antipsychotic treatment in eight studies. A pooled ES of −0.003 (p = 0.96) showed no change in peripheral BDNF level after treatment. Conclusion: Peripheral BDNF level was decreased in FEP compared to HC, but it did not change after treatment.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

Cardiovascular Risk Factors and Insulin Resistance after Two Hypocaloric Diets with Different Fat Distribution in Obese Subjects: Effect of the rs10767664 Gene Variant in Brain-Derived Neurotrophic Factor

BACKGROUND

The role of brain-derived neurotrophic factor (BDNF) variants on change in body weight and cardiovascular risk factors after weight loss remains unclear in obese patients.

OBJECTIVE

Our aim was to analyze the effects of the rs10767664 BDNF gene polymorphism on body weight, cardiovascular risk factors, and serum adipokine levels after a high monounsaturated fatty acids (MUFAs) hypocaloric diet (diet M) versus a high polyunsaturated fatty acids (PUFAs) hypocaloric diet (diet P).

METHODS

A Caucasian population of 361 obese patients was enrolled. Subjects who met the inclusion criteria were randomly allocated to one of two diets for a period of 3 months.

RESULTS

Two hundred and sixteen subjects (59.8%) had the genotype AA (wild-type group), and 145 (40.2%) patients had the genotypes AT (122 patients, 33.8%) or TT (23 patients, 6.4%) (mutant-type group). After weight loss with diet P and diet M and in both genotype groups, body mass index, weight, fat mass, waist circumference, systolic blood pressure, serum leptin levels, low-density lipoprotein cholesterol, and total cholesterol decreased in a significant way. Secondary to weight loss with diet M and only in the wild-type group, insulin levels (-2.1 ± 2.0 vs. -0.7 ± 2.9 IU/L, p < 0.05) and homeostatic model assessment of insulin resistance (-0.7 ± 0.9 vs. -0.3 ± 1.0 U, p < 0.05) decreased.

CONCLUSION

Our data show that the rs10767664 variant of the BDNF gene modifies insulin resistance and insulin levels after weight loss with a hypocaloric diet enriched with MUFAs.