Difference in inflammatory cytokine production by mononuclear cells from obese and non-obese schizophrenic patients

Selenium as a Factor Moderating Depression and Obesity in Middle-Aged Women

The aim of this study was to evaluate the effect of serum selenium on PPAR-γ and the selected proinflammatory cytokines (IL-1β, IL-6, TNF-α) in relation to depressive symptoms and obesity in middle-aged women. The research procedure was as follows: a survey was performed using the authors’ questionnaire and the BDI, anthropometric measurements, and the analysis of blood for the levels of selenium, cytokines, and genetic analysis of the PPAR-γ polymorphism (n = 443). It was found that the BMI increased along with the concentration of IL-6. No moderating effect of selenium was observed, although the cut-off values for “p” were established for IL-β*Se (p = 0.068) and IL-6*Se (p = 0.068), so there was a potential association with these two markers. At high selenium levels, the effect of higher IL-β levels on a decrease in BMI was stronger, as was the effect of an increase in IL-6 levels on an increase in BMI. No effect of selenium on PPAR-γ was found in relation to depressive symptoms and obesity. Higher selenium levels may have a beneficial effect on BMI even at high IL-β concentrations, however, at high IL-6 concentrations, this effect was not observed. Selenium levels had no impact on depressive symptoms.

TonEBP in Myeloid Cells Promotes Obesity-Induced Insulin Resistance and Inflammation Through Adipose Tissue Remodeling

The phenotypic and functional plasticity of adipose tissue macrophages (ATMs) during obesity plays a crucial role in orchestration of adipose and systemic inflammation. Tonicity-responsive enhancer binding protein (TonEBP) (also called NFAT5) is a stress protein that mediates cellular responses to a range of metabolic insults. Here, we show that myeloid cell-specific TonEBP depletion reduced inflammation and insulin resistance in mice with high-fat diet-induced obesity but did not affect adiposity. This phenotype was associated with a reduced accumulation and a reduced proinflammatory phenotype of metabolically activated macrophages, decreased expression of inflammatory factors related to insulin resistance, and enhanced insulin sensitivity. TonEBP expression was elevated in the ATMs of obese mice, and Sp1 was identified as a central regulator of TonEBP induction. TonEBP depletion in macrophages decreased induction of insulin resistance-related genes and promoted induction of insulin sensitivity-related genes under obesity-mimicking conditions and thereby improved insulin signaling and glucose uptake in adipocytes. mRNA expression of TonEBP in peripheral blood mononuclear cells was positively correlated with blood glucose levels in mice and humans. These findings suggest that TonEBP in macrophages promotes obesity-associated systemic insulin resistance and inflammation, and downregulation of TonEBP may induce a healthy metabolic state during obesity.

Prospective cohort study of the evaluation of patient benefit from the redevelopment of a complete national forensic mental health service: the Dundrum Forensic Redevelopment Evaluation Study (D-FOREST) protocol

INTRODUCTION

Secure forensic mental health services are low volume, high cost services. They offer care and treatment to mentally disordered offenders who pose a high risk of serious violence to others. It is therefore incumbent on these services to systematically evaluate the outcomes of the care and treatment they deliver to ensure patient benefit in multiple domains. These should include physical and mental health outcomes, as well as offending related outcomes. The aim of Dundrum Forensic Redevelopment Evaluation Study (D-FOREST) is to complete a structured evaluation study of a complete national forensic mental health service, at the time of redevelopment of the National Forensic Mental Health Service for the Ireland.

METHODS AND ANALYSIS

D-FOREST is a multisite, prospective observational cohort study. The study uses a combination of baseline and repeated measures, to evaluate patient benefit from admissions to forensic settings. Patients will be rated for physical health, mental health, offending behaviours and other recovery measures relevant to the forensic hospital setting at admission to the hospital and 6 monthly thereafter.Lagged causal model analysis will be used to assess the existence and significance of potential directed relationships between the baseline measures of symptomatology of schizophrenia and violence risk and final outcome namely length of stay. Time intervals including length of stay will be measured by median and 95% CI using Kaplan-Meier and Cox regression analyses and survival analyses. Patient related measures will be rated as changes from baseline using general estimating equations for repeated measures, analysis of variance, analysis of covariance or logistic regression.

ETHICS AND DISSEMINATION

The study has received approval from the Research Ethics and Effectiveness Committee of the National Forensic Mental Health Service, Ireland. Results will be made available to the funder and to forensic psychiatry researchers via international conferences and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

NCT05074732.

History of Suicide Attempts and COVID-19 Infection in Veterans with Schizophrenia or Schizoaffective Disorder: Moderating Effects of Age and Body Mass Index

Introduction

Relative to the general population, patients with schizophrenia or schizoaffective disorder have higher rates of suicide attempts and mortality from COVID-19 infection. Therefore, determining whether a history of suicide attempt is associated with COVID-19 in patients with schizophrenia or schizoaffective disorder has implications for COVID-19 vulnerability stratification in this patient population.

Methods

We carried out cross-sectional analyses of electronic health records of veterans with a diagnosis of schizophrenia or schizoaffective disorder that received treatment at any United States Veterans Affairs Medical Center between January 1, 2020, and January 31, 2021. We used logistic regression to estimate unadjusted and adjusted (including age, sex, race, marital status, body mass index (BMI), and a medical comorbidity score) odds ratios (ORs) for COVID-19 positivity in suicide attempters relative to nonattempters.

Results

A total of 101,032 veterans (mean age 56.67 ± 13.13 years; males 91,715 [90.8%]) were included in the analyses. There were 2,703 (2.7%) suicide attempters and 719 (0.7%) patients were positive for COVID-19. The association between history of suicide attempt and COVID-19 positivity was modified by age and BMI, such that the relationship was only significant in patients younger than 59 years, and in obese (BMI ≥30) patients (adjusted OR 3.42, 95% CI 2.02–5.79 and OR 2.85, 95% CI 1.65–4.94, respectively).

Conclusions

Higher rates of COVID-19 in young or obese suicide attempters with a diagnosis of schizophrenia or schizoaffective disorder might be due to the elevated risk for the infection in this subgroup of patients.

Metabolic Syndrome is Associated with Oxidative Stress and Proinflammatory State

Metabolic syndrome (MetS) is associated with increased risk of developing diabetes and cardiovascular diseases. MetS is also characterized by an increase of oxidative stress which contributes to impaired inflammation, vascular function, and atherosclerosis. The aim was to assess the oxidative stress and inflammatory markers in plasma and PBMCs in adults with or without MetS. Antioxidant and inflammatory parameters were measured in peripheral blood mononuclear cells (PBMCs) of 80 men and 80 women over 55 to 80-years-old residing in the Balearic Islands without previously documented cardiovascular disease. Circulating leukocytes, neutrophils, lymphocytes, basophils, and monocytes were higher in MetS subjects with respect to those without MetS. Plasma levels of malondialdehyde, tumor necrosis factor α (TNFα), and interleukin 6 (IL-6) levels were higher in MetS subjects in both genders, but the superoxide dismutase activity was lower. The myeloperoxidase plasma activity was higher in the MetS male subjects. Higher activities and protein levels of catalase and glutathione reductase in PBMCs were observed in MetS subjects in both genders. Obtained data show that MetS is associated with oxidative stress and a proinflammatory state and with high antioxidant defenses in PBMCs probably derived from a pre-activation state of immune cells.

Association Between SIRT1, Cytokines, and Metabolic Syndrome in Schizophrenia Patients With Olanzapine or Clozapine Monotherapy

Objective: Previous studies consistently showed the interaction between Sirtuin 1 (SIRT1) and immune inflammation is significantly related to metabolic abnormalities, but their role in the pathogenesis of metabolic syndrome caused by second-generation antipsychotics (SGAs) in schizophrenia patients largely remains unknown. Hence, the present study aimed to fill this gap. Methods: A total of 54 schizophrenia patients with olanzapine or clozapine monotherapy [metabolic syndrome (MetS)/non-MetS patients, 27/27] and 67 healthy subjects were recruited in the present study. The Positive and Negative Syndrome Scale was used, and the plasma levels of SIRT1, interleukin 6 (IL-6), IL-8, IL-10, and tumor necrosis factor α (TNF-α) were measured. Results: The results showed that schizophrenia patients treated with olanzapine or clozapine (both MetS and non-MetS groups) had significantly higher plasma levels of IL-6, IL-10, and TNF-α compared to normal controls (all P < 0.05). Moreover, the MetS patients exhibited markedly lower plasma levels of SIRT1 and higher plasma levels of IL-6 than non-MetS patients and normal controls (all P < 0.05). However, there were no significant differences in IL-8 levels between groups. Our correlation analysis showed that SIRT1 was significantly correlated with diastolic blood pressure, triglyceride, and high-density lipoprotein cholesterol in schizophrenia patients. The stepwise logistic regression analysis further identified the IL-6 × SIRT1 (β = -0.463, t = 10.040, P = 0.002) as the influencing factor for the MetS in the patients. Conclusion: Our preliminary findings suggest that SIRT1 interacted with inflammatory cytokines associated with MetS in schizophrenia patients treated with SGA monotherapy.

Plasmacytoid dendritic cell and myeloid dendritic cell function in ageing: A comparison between elderly and young adult women

Ageing is associated with a changing immune system, leading to inflammageing (increased levels of inflammation markers in serum) and immunosenescence (reduced immune cells and reduced responses towards pathogens). This results in reduced vaccination responses and increased infections in elderly. Much is known about the adaptive immune system upon ageing, but less is known about the innate immune system. Therefore, the aim of this study was to compare innate immune function of Toll like receptor (TLR)-mediated responses between elderly and young adult women.

To this end, elderly and young adult women were compared to study the effect of ageing on the relative prevalence and reactivity to TLR-mediated responses of myeloid- and plasmacytoid dendritic cells (mDC, pDC). In addition, TLR expression and inflammatory markers in serum were investigated. Elderly women had reduced numbers of circulating pDCs. In addition, pDCs and mDCs of elderly women responded differently towards TLR stimulation, especially TLR7/8 mediated stimulation was reduced, compared to young adults. In serum, markers involved in inflammation were generally increased in elderly. In conclusion, this study confirms and extends the knowledge about immunosenescence and inflammageing on innate immunity in elderly women.

In vitro cytokine synthesis in unstimulated and mitogen-stimulated peripheral blood mononuclear cells from individuals with schizophrenia

Increasing evidence has shown that the immune system is involved in the schizophrenia development, with alterations in immune cell reactivity being one possible factor contributing to its pathogenesis. The purpose of the study was to evaluate in vitro the capability of peripheral blood mononuclear cells (PBMCs) obtained from subjects with schizophrenia and controls to engage in spontaneous and phytohemagglutinin (PHA)-stimulated cytokine production. The concentrations of various cytokines (interleukin (IL)-1β, IL-17A, tumor necrosis factor (TNF), interferon (IFN)-γ and IL-10) in supernatants from cultured PBMCs were measured using the cytometric bead array. No significant differences in the spontaneous production of IL-1β, IL-17A, IFN-γ and IL-10 by PBMCs were detected between individuals with schizophrenia and controls. TNF synthesis by PBMCs was found to be lower among those with schizophrenia. In all subjects and controls, greater cytokine generation was associated with PBMCs treated with PHA compared with those that were not. The PBMCs from people with schizophrenia displayed considerably higher sensitivity to mitogen stimulation, as the production of IL-17A, TNF and IFN-γ was at least threefold of that observed in healthy subjects, which may be driven by antipsychotics taken by patients with schizophrenia. Correlation was observed between spontaneous production of IFN-γ and Positive and Negative Syndrome Scale G subscore (which measures the general symptoms of schizophrenia) and between PHA-stimulated synthesis of IL-17A and G subscore. Our data confirm that the immune system dysregulation may underlie schizophrenia pathophysiology. There is a potential possibility that immunological tests could be used as a diagnostic, therapeutic and side-effects biomarker for schizophrenia, but further studies are needed.

Association between IL-6 and metabolic syndrome in schizophrenia patients treated with second-generation antipsychotics

OBJECTIVE

Second-generation antipsychotics (SGAs) have a high risk of causing metabolic syndrome (MetS). There is accumulating evidence supporting the fact that the activation of inflammatory pathway contributes to the development of MetS and further aggravates cognitive impairment. This study aimed to investigate the relationship between interleukin-6 (IL-6), cognitive function, and MetS in schizophrenia patients treated with SGAs.

METHODS

One hundred and seventy-four patients with schizophrenia using SGAs were divided into MetS and non-MetS group, based on the criteria of the National Cholesterol Education Program's Adult Treatment Panel III. Cognitive function was measured using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). A total of 138 patients and 29 healthy controls were examined in the plasma IL-6 levels.

RESULTS

The prevalence of MetS in schizophrenia patients treated with SGAs was 33% in this study. There were no significant differences in cognitive functions (both RBANS total score and subscale score) between MetS and non-Mets patients (P>0.05). Patients with MetS had higher plasma levels of IL-6 compared to non-MetS patients (P=0.019). However, such difference was only found in male patients (male: P=0.012; female: P=0.513). The partial correlational analysis further showed that IL-6 levels were notably negative related to the HDL levels in male schizophrenia patients after age, years of education, body mass index (BMI), age of onset, total disease course, and equal dose of olanzapine were controlled (male: P=0.009; female: P=0.450). In addition, the multiple regression analysis (stepwise model) performed in the male patient subgroup showed that IL-6 (beta =-0.283, t=-2.492, P=0.015) was an independent contributor to the HDL levels. However, the IL-6 was not an independent contributor to the HDL levels in female patients.

CONCLUSION

Our findings provide evidence suggesting that the immune-inflammatory effect of IL-6 on SGAs-induced MetS may be in a gender manner.

Kinetics of Cytokine Levels during Antipsychotic Treatment in Schizophrenia: A Meta-Analysis

BACKGROUND

Immune system dysfunction is a hypothesis in the psychopathology of schizophrenia, but the impact of antipsychotic treatment within this system is not clear. The aim of this meta-analysis was to investigate the impact of antipsychotic treatment on cytokine levels in in vivo studies on schizophrenia.

METHODS

After a systematic database search, original data were extracted with the help of certain authors. Means and SDs were extracted to calculate standardized mean differences. Cytokine levels were compared in vivo in schizophrenia patients, before and after antipsychotic treatment. Meta-regressions were performed to explore the influence of demographic and clinical variables on cytokine level standardized mean differences. Stratifications by treatment and diagnosis were also performed.

RESULTS

Forty-seven studies were included in this meta-analysis. Proinflammatory cytokine level decreases were found for interleukin-1 β levels (P<.0001) and interferon-γ (P=.01) and a statistical trend towards a decrease in interleukin-6 (P=.08) and tumor necrosis factor-α (P=.07) levels. An antiinflammatory cytokine level increase was found for soluble tumor necrosis factor-R2 (P<.001) and soluble interleukin 2-R (P=.03) levels. A meta-regression analysis found a correlation between interleukin-6 level standardized mean differences and positive schizophrenia symptom score standardized mean differences before and after treatment (P=.01). Stratification by diagnosis or treatment found a possible impact of the kinetics of cytokine levels.

CONCLUSIONS

The present meta-analysis provides evidence that antipsychotic treatment has an antiinflammatory effect and could normalize immune balance dysfunction in schizophrenia. Interleukin-6 level normalization could be a marker of illness equilibration and thus used in clinical practice.

Cytokines dysregulation in schizophrenia: A systematic review of psychoneuroimmune relationship

INTRODUCTION

Schizophrenia is a multifactorial psychiatric disease with complex interactions among the brain and the immune system. A psycho-immune relationship underling schizophrenia is supported by several studies and integrates a specific area of knowledge - psychoneuroimmunology.

METHODS

A systematic review was performed by 2009 Preferred Reporting Items (PRISMA) recommendations. Based on the inclusion/exclusion criteria, publications with relevant information (evaluated by the Joanna Briggs Institute Critical Appraisals tools to quality assessment) were included.

RESULTS

In this review, we considered the inflammatory activity promoted by cytokine alterations in schizophrenia aetiology, which reflects the systemic comprehension of this disease in opposition to the traditional approach focused solely on the brain. We focus on the analysis of several specific outcomes, such as proinflammatory cytokines, sample sort, laboratory techniques, diagnosis scales and results of each publication.

CONCLUSION

This systematic review confirms the existence of cytokines abnormalities in schizophrenia disease. Immune imbalances such as increased levels of some cytokines (either at protein level or at mRNA expression), cytokine mRNAs, as well as cytokine gene polymorphisms have been reported with a large support in schizophrenia. These findings provide a strong evidence of a concomitant process of inflammatory activity in schizophrenia illness course.

No Effect of Adjunctive Minocycline Treatment on Body Metabolism in Patients With Schizophrenia

PURPOSE/BACKGROUND

This study examined the effect of adjunctive minocycline on body metabolism in risperidone-treated patients with schizophrenia.

METHODS/PROCEDURES

Each subject had a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of schizophrenia and had been on stable dose of risperidone for at least 4 weeks. In a 16-week randomized, double-blind, placebo-controlled study, subjects received either minocycline (200 mg/d) or placebo. Various metabolic parameters, including weight, waist circumference, fasting insulin, glucose, and lipids, were measured at baseline and week 16.

FINDINGS/RESULTS

A total of 63 subjects with schizophrenia were enrolled in the study. Fifty-five patients completed week-16 assessments (27 in the minocycline group, 28 in the placebo group). There were no significant differences between the 2 groups in week 16 changes for body weight, body mass index, waist circumference, fasting insulin, glucose, and lipids (P's > 0.300).

IMPLICATIONS/CONCLUSIONS

In the present study, adjunctive treatment of minocycline did not seem to improve body metabolism in patients with schizophrenia receiving risperidone. The implications for future studies were discussed.

Serum levels of interleukin 6 in schizophrenic patients during treatment augmentation with sarcosine (results of the PULSAR study)

OBJECTIVE

Augmentation of sarcosine, a natural inhibitor of the glycine transporter type I, normalizes glutamatergic neurotransmission, having beneficial impact on primary negative symptoms in schizophrenia and may also influence immune system and interleukin 6 (IL-6) levels.

AIM

Finding a relationship between initial IL-6 serum concentrations or its changes and severity of symptoms as a result of sarcosine addition to stable antipsychotic treatment.

METHOD

Fifity-eight individuals with schizophrenia with predominantly negative symptoms completed a 6-month randomized, double-blind placebo-controlled prospective study. Patients received 2 g of sarcosine (n = 29) or placebo (n = 30) daily per os. We measured IL-6 levels and severity of symptoms at the beginning, after 6 weeks and 6 months. As main clinical tools, we used Positive and Negative Syndrome Scale (PANSS) and Calgary depression scale for schizophrenia (CDSS).

RESULTS

Augmentation with sarcosine had no effect on IL-6 serum levels in all time points. We noted significant improvements in negative symptoms, general psychopathology, and total PANSS score in the sarcosine group. We found correlation of initial serum IL-6 with severity of positive symptoms and negative association between IL-6 levels reduction and positive symptoms reduction.

CONCLUSIONS

Sarcosine does not significantly affect IL-6 concentrations but IL-6 may be involved in mechanisms related to the presence of positive symptoms.

Exercise-induced modulation of histone H4 acetylation status and cytokines levels in patients with schizophrenia

The present study aimed to investigate the short and long-term effects of a concurrent exercise protocol on global histone H4 acetylation levels and inflammatory markers (interleukin-4 (IL-4), interleukin-6 (IL-6), interferon gamma (IFN-γ) and cortisol) in phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMC) and in peripheral blood of patients with schizophrenia (SZ), as well the intervention impact on anthropometric characteristics. Seventeen individuals were submitted to the intervention three times a week and blood samples were collected pre, 30, 60 and 90days after the intervention started. A remarkable reduction on body mass index and body mass were observed following intervention. The protocol also induced a histone H4 hypoacetylation status in PBMC all times evaluated when compared to the pre intervention period. Although the IL-4 and cortisol levels were not altered in response to the intervention, a reduction in IL-6 production during the 60 and 90days compared to the pre intervention period was observed. Finally, diminished IFN-γ production was found in the 90days period compared to the pre intervention and 30days after periods. In addition, systemic IL-6 levels were lower at 60 and 90days compared to the pre intervention. The concurrent exercise protocol was able to improve anthropometric characteristics in patients with SZ, engaging the modulation of cytokine and histone H4 acetylation levels.

Adiposity-independent hypoadiponectinemia as a potential marker of insulin resistance and inflammation in schizophrenia patients treated with second generation antipsychotics

OBJECTIVE

The purpose of this study was to explore body fat independent effect of second generation antipsychotics (SGAs) on measures of glucose and adipokine homeostasis, and markers of inflammation.

METHOD

Eight non-diabetic men with schizophrenia (age: 55±3years, BMI: 29.7±1.2kg/m(2)) on SGAs were studied after an overnight fast. DXA and single-cut CT of abdomen were respectively used for the assessment of total body and abdominal fat. Blood samples were collected for measurements of glucose, insulin, leptin, adiponectin, C-reactive protein (CRP), and TNF-α. Data in schizophrenic subjects were compared to eight age (55±2.8years) and BMI (29.6±1.1kg/m(2)) matched healthy men.

RESULTS

The results were significant for markedly decreased serum adiponectin in schizophrenia patients (4.6±0.9 vs 11.1±1.5ng/mL, p=0.001). Lower levels of adiponectin in schizophrenia men were associated with significant increases in insulin resistance (4.2±0.7 vs 1.7±0.4, p=0.004), CRP (3.5±1.2 vs 1.2±0.3, p=0.037), and leptin (12±1.4 vs 8.5±1.4ng/mL, p=0.05). Various measures of adiposity, including fat mass index (FMI) and abdominal fat were not different in the two study groups.

CONCLUSIONS

These findings in the context of comparable age and total body/abdominal fat mass are assumed to be either disease specific, and/or treatment inflicted. The definitive invoking etiology and a presumptive role of hypoadiponectinemia in the development of insulin resistance and increased risk of inflammation warrant future investigation.

Glutathione S-transferase K1 genotype and overweight status in schizophrenia patients: A pilot study

Elevated oxidative stress in mitochondria and mitochondrial dysfunction are associated with weight gain in schizophrenia (SCZ) patients. Glutathione S-transferase kappa 1 (GSTK1) protects cells against exogenous and endogenous oxidative stress in the mitochondria. This exploratory study investigated the possible effects of a common GSTK1 polymorphism (rs1917760, G-1308T) on the risk for overweight status among 329 SCZ patients and 305 age- and gender-matched controls and on the GSTK1 mRNA level in peripheral blood mononuclear cells among 14 SCZ patients. The GSTK1 T/T genotype was associated with having a higher BMI value among SCZ male patients, whereas this genotype tended to be associated with a lower BMI value among female patients. Conversely, these associations were not observed among the controls. The GSTK1 T/T genotype was associated with decreased GSTK1 mRNA level among SCZ patients. The GSTK1 T/T genotype may be a novel risk factor for the prediction of overweight status in SCZ male patients, although the results of this pilot study should be verified by a larger study.

Promising link between selenium and peroxisome proliferator activated receptor gamma in the treatment protocols of obesity as well as depression

Considerable interest has been given to the significance of peroxisome proliferator activated receptors (PPARs) in macronutrient metabolism, however, there is not sufficient data concerning the interactions between PPARs and micronutrients. Investigations performed on PPARγ and one of the essential micronutrients selenium (Se) have shown that both parameters may lead to alterations in obesity-related or mood disorders. Therefore, it is plausible to consider PPARγ and Se together as a powerful combination during the treatment of two associated diseases; obesity and depression. PPARγ has been shown to be involved in the antidepressant-like activity. It is also an important parameter to be considered in obesity as the master regulator of adipogenesis. The mechanism of action of PPARγ is initiated by ligand binding which induces a conformational change in the receptor. Se is capable of alleviating inflammatory signaling pathways. Obesity is associated with chronic low-grade inflammation. Depression is also defined as an inflammatory disorder. Inflammatory mediators such as tumor necrosis factor-alpha (TNFα) participate in the progression of depression. They are also obesity-associated parameters. Due to TNFα induced depressive-like behaviors and the positive association between this proinflammatory cytokine and obesity, TNFα-activated signaling pathways and those inhibiting them have recently gained importance as potential targets and therapeutic tools, respectively. More studies are necessary to develop compounds with therapeutic nature against depressive disorders and obesity. PPARγ is an important signaling pathway that occurs at the crossroads of depression and obesity. Se, aside from its anti-inflammatory, anticarcinogenic and antioxidative nature, affects also the way of PPARγ action. Se supplementation or fortification as well as the development of the partial agonists of PPARγ in which lipophilic Se compounds are used as ligand followed by experimental trials and human studies using the newly developed compounds will be promising approaches for future hope during the treatment of these diseases.

Inflammatory Cytokines and Antipsychotic-Induced Weight Gain: Review and Clinical Implications

Antipsychotic medications (APs), particularly second-generation APs, are associated with significant weight gain in schizophrenia patients. Recent evidence suggests that the immune system may contribute to antipsychotic-induced weight gain (AIWG) via AP-mediated alterations of cytokine levels. Antipsychotics with a high propensity for weight gain, such as clozapine and olanzapine, influence the expression of immune genes, and induce changes in serum cytokine levels to ultimately down-regulate neuroinflammation. Since inflammatory cytokines are normally involved in anorexigenic responses, reduced inflammation has been independently shown to mediate changes in feeding behaviours and other metabolic parameters, resulting in obesity. Genetic variation in pro-inflammatory cytokines is also associated with both general obesity and weight change during AP treatment, and thus, may be implicated in the pharmacogenetics of AIWG. At this time, preliminary data support a cytokine-mediated model of AIWG which may have clinical utility in developing more effective metabolic monitoring guidelines and prevention measures. However, further research is still needed to clearly elucidate the validity of this immune model. This article reviews the evidence implicating inflammatory cytokines in AIWG and its potential clinical relevance.

Are leptin levels increased among people with schizophrenia versus controls? A systematic review and comparative meta-analysis

OBJECTIVE

Leptin may play a role in the pathophysiology of schizophrenia and it remains unclear if levels are raised compared to controls. Therefore, we performed a systematic review and meta-analysis comparing leptin levels among people with schizophrenia and controls.

METHOD

Two authors independently searched major electronic databases from inception until June 2015 for studies measuring blood leptin levels among people with schizophrenia and controls. Random effects meta-analysis calculating hedges g and 95% confidence intervals (CI) and meta-regression analyses were conducted.

RESULTS

Twenty-seven articles representing 1674 individuals with schizophrenia (34.6 ± 6.8 years, 55% male (0-100%), BMI 25.2 ± 3.1) and 2033 controls (33.9 ± 7.0 years, 51% male (0-100%), BMI=24.1 ± 2.1) were included. Across all studies, leptin levels may be marginally higher in schizophrenia (g=0.164, 95% CI -0.014-0.341, p=0.07, Q=217, p<0.01), particularly when one outlier was removed (g=0.196, 95% CI 0.210-0.370, p=0.02) and when we included the smallest effect size from studies with multiple comparisons (g=0.318, 95% CI 0.125-0.510, p=0.001). Leptin levels were higher in multi-episode schizophrenia (g=0.245, 95% CI 0.058-0.433, p=0.01) and females (g=0.557 95% CI 0.16-0.954, p=0.006). Subgroup analyses revealed leptin levels may be higher in participants taking second-generation antipsychotics compared to controls. Multivariate meta-regression demonstrated a lower percentage of males (β=-0.0064, 95% CI -0.0129 to -0.0002, p=0.05), but not BMI, moderated the results.

CONCLUSION

Our results suggest that schizophrenia is associated with increased blood leptin levels compared to controls, which may not be entirely attributable to antipsychotic medication or BMI. Other illness related and lifestyle choices may play a pivotal role.