A novel biomarker of cardiometabolic pathology in schizophrenia?

Differences in metabolic biomarkers in people with schizophrenia who are of Mexican descent compared to non-Hispanic whites

Metabolic dysfunction is highly prevalent and contributes to premature mortality among people with schizophrenia (PwS), especially in Hispanic/Latino/a/x/e PwS, compared to non-Hispanic White (NHW) PwS. This study evaluated the relative contributions of Mexican descent and schizophrenia diagnosis to metabolic biomarker levels. This cross-sectional study included 115 PwS and 102 non-psychiatric comparison (NC) participants - English-speakers aged 26-66 years, 27% Mexican descent, and 52% women across both groups. Assessments included evaluations of BMI, psychopathology, and fasting metabolic biomarkers. We used ANOVA analyses to compare metabolic outcomes between diagnostic and ethnic subgroups, linear regression models to examine associations between Mexican descent and metabolic outcomes, and Spearman's correlations to examine relationships between metabolic outcomes and illness-related variables in PwS. Mexican PwS had higher hemoglobin A1c levels, insulin resistance, and body mass index than NHW PwS. Mexican descent was associated with higher hemoglobin A1c levels, insulin resistance, body mass index, and leptin levels, controlling for age, sex, depression, education, and smoking. Among Mexican PwS, worse negative symptoms were associated with greater insulin resistance. These findings support the possibility of ethnicity-based differences in metabolic dysregulation, though further investigation is warranted to create targeted health interventions for Hispanic PwS.

WISER Survivor Trial: Combined Effect of Exercise and Weight Loss Interventions on Adiponectin and Leptin Levels in Breast Cancer Survivors with Overweight or Obesity

Adipocyte dysregulation is one mechanism linking overweight and breast cancer recurrence. Exercise and weight loss are associated with a decreased risk of breast cancer recurrence in breast cancer survivors with overweight or obesity, which may be mediated through reduced leptin levels, increased adiponectin levels, and an elevated adiponectin to leptin (A:L) ratio. The four-arm randomized controlled WISER Survivor trial examined the 12-month intervention effects of exercise, weight loss, and the combination of exercise and weight loss on adipokine levels among breast cancer survivors (n = 339) with overweight or obesity. Compared with Control, the Combination of Exercise and Weight Loss decreased leptin levels (-35.9%; 95% CI: -46.8%, -25.0%) and increased A:L ratio (11.6%; 95% CI: 5.6%, 17.6%) but did not change adiponectin levels (4.1%; 95% CI: -3.1%, 11.2%). Compared with Control, Weight Loss Alone decreased leptin levels (-35.6%; 95% CI: -46.6%, -24.5%) and increased A:L ratio (10.6%; 95% CI: 4.7%, 16.5%) but did not change adiponectin levels (0.9%; 95% CI: -6.0%, 7.9%). Compared with Control, Exercise Alone did not change leptin levels, adiponectin levels, or A:L ratio. In analyses that consolidated intervention groups, compared with Control, weight loss of ≥5% decreased leptin levels (p trend < 0.01) and increased A:L ratio (p trend < 0.01) but did not alter adiponectin levels (p trend = 0.53). Weight loss, with or without exercise, was associated with decreased leptin levels in breast cancer survivors with overweight or obesity. Improvements in the adipokine secretion profile (A:L ratio) were primarily driven by a weight loss-induced change in leptin levels.

Effects of a six-month yoga intervention on the immune-inflammatory pathway in antipsychotic-stabilized schizophrenia patients: A randomized controlled trial

BACKGROUND

Schizophrenia is a complex neuropsychiatric disorder for which several etiopathological theories have been proposed, one of the prominent ones being immune dysfunction. Recent studies on yoga as an add-on therapy have shown improvement in negative symptoms, cognition, and quality of life in schizophrenia patients. However, the biological mechanism/s of action of yoga in schizophrenia are not clear. The current study was aimed at exploring the effects of long-term (6 months) add-on yoga therapy on the immune inflammatory pathway in schizophrenia patients.

METHODS

Sixty schizophrenia patients were randomized to add-on yoga therapy (YT=30) and treatment-as-usual (TAU=30) groups of which 21 patients in YT and 20 in TAU group completed the study. Blood samples and clinical assessments were obtained at baseline and at the end of 6 months. The plasma levels of nine cytokines (IL-2, IL-4, IL-5, IL-10, IL-12(p70), IL-13, GM-CSF, IFN-γ, and TNF-α) were quantified using multiplex suspension array. The clinical assessments included SAPS, SANS, BPRS, PSS, CGI, SOFS and WHOQUOL-BREF.

RESULTS

Patients in the yoga group showed significant reductions in plasma TNF-α (Z = 2.99, p = 0.003) and IL-5 levels (Z = 2.20, p = 0.03) and greater clinical improvements in SAPS, SANS, PSS, and SOFS scores as compared to TAU group. Further, plasma TNF-α levels exhibited a positive correlation with negative symptoms (r_s =0.45, p = 0.02) and socio-occupational functioning (r_s =0.61, p = 0.002) in the YT group.

CONCLUSIONS

The findings of the study suggest that improvements in schizophrenia psychopathology with yoga interventions are associated with immuno-modulatory effects.

Potential Inflammatory Biomarker in Patients with Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder that can diminish the quality of life of both children and adults in academic, occupational, and social contexts. The kynurenine pathway (KP) contains a set of enzymatic reactions involved in tryptophan (TRP) degradation. It is known to be associated with the risk of developing ADHD. This review will address the KP and underlying mechanism of inflammation in ADHD. Potential inflammatory biomarkers reported in the most recent studies are summarized. Although a strong neuroimmunological basis has been established due to the advances of recent neurobiological research, the pathophysiology of ADHD remains unclear.

Recent advancements in biomarker research in schizophrenia: mapping the road from bench to bedside

Schizophrenia (SZ) is a severe progressive neurodegenerative as well as disruptive behavior disorder affecting innumerable people throughout the world. The discovery of potential biomarkers in the clinical scenario would lead to the development of effective methods of diagnosis and would provide an understanding of the prognosis of the disease. Moreover, breakthrough inventions for the treatment and prevention of this mysterious disease could evolve as a result of a thorough understanding of the clinical biomarkers. In this review, we have discussed about specific biomarkers of SZ an emphasis has been laid to delineate (1) diagnostic biomarkers like neuroimmune biomarkers, metabolic biomarkers, oligodendrocyte biomarkers and biomarkers of negative and cognitive symptoms, (2) therapeutic biomarkers like various neurotransmitter systems and (3) prognostic biomarkers. All the biomarkers were evaluated in drug-naïve (at least for 4 weeks) patients in order to achieve a clear comparison between schizophrenic patients and healthy controls. Also, an attempt has been made to elucidate the potential genes which serve as predictors and tools for the determination of biomarkers and would ultimately help in the prevention and treatment of this deadly illness.

Immuno-metabolic profile of patients with psychotic disorders and metabolic syndrome. Results from the FACE-SZ cohort

Background

Metabolic syndrome (MetS) is a highly prevalent and harmful medical disorder often comorbid with psychosis where it can contribute to cardiovascular complications. As immune dysfunction is a key shared component of both MetS and schizophrenia (SZ), this study investigated the relationship between immune alterations and MetS in patients with SZ, whilst controlling the impact of confounding clinical characteristics including psychiatric symptoms and comorbidities, history of childhood maltreatment and psychotropic treatments.

Method

A total of 310 patients meeting DSM-IV criteria for SZ or schizoaffective disorders (SZA), with or without MetS, were systematically assessed and included in the FondaMental Advanced Centers of Expertise for Schizophrenia (FACE-SZ) cohort. Detailed clinical characteristics of patients, including psychotic symptomatology, psychiatric comorbidities and history of childhood maltreatment were recorded and the serum levels of 18 cytokines were measured. A penalized regression method was performed to analyze associations between inflammation and MetS, whilst controlling for confounding factors.

Results

Of the total sample, 25% of patients had MetS. Eight cytokines were above the lower limit of detection (LLOD) in more than 90% of the samples and retained in downstream analysis. Using a conservative Variable Inclusion Probability (VIP) of 75%, we found that elevated levels of interleukin (IL)-6, IL-7, IL-12/23 p40 and IL-16 and lower levels of tumor necrosis factor (TNF)-α were associated with MetS. As for clinical variables, age, sex, body mass index (BMI), diagnosis of SZ (not SZA), age at the first episode of psychosis (FEP), alcohol abuse, current tobacco smoking, and treatment with antidepressants and anxiolytics were all associated with MetS.

Conclusion

We have identified five cytokines associated with MetS in SZ suggesting that patients with psychotic disorders and MetS are characterized by a specific “immuno-metabolic” profile. This may help to design tailored treatments for this subgroup of patients with both psychotic disorders and MetS, taking one more step towards precision medicine in psychiatry.

Adiponectin and Stnfr2 peripheral levels are associated with cardiovascular risk in patients with schizophrenia

OBJECTIVES

To investigate the association between cytokine peripheral levels and the risk of cardiovascular disease in patients with schizophrenia and controls.

METHODS

A sample of 40 patients and 40 control subjects participated in the study. Psychiatric diagnosis was established following structured clinical assessment. The Framingham Score was used to assess cardiovascular risk (CVR). Serum levels of the cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α were determined by cytometric bead array (CBA) technique, and the serum levels of IL-33, sST2, sTNFR1, sTNFR2, Leptin and Adiponectin by Enzyme-Linked Immunosorbent assay (ELISA).

RESULTS

Patients with schizophrenia showed greater frequency of moderate CVR when compared with controls (p = 0.14). In addition, patients showed higher levels of sTNFR2 and Adiponectin compared to controls (p = 0.007 and p < 0.001, respectively). Adiponectin and sTNFR2 were associated with CVR only in patients (p = 0.0002 and p = 0.033, respectively). In multivariate analysis controlling for socio-demographic and clinical confounders, illness duration (r = 0.492; p < 0.002) and sTNFR2 (r = 0.665; p < 0.004) were independent predictors of CVR.

CONCLUSION

Our results reinforce the concept that patients with schizophrenia are at greater risk to develop cardiovascular diseases, and suggest that the associated chronic low-grade inflammation might play a role in this process.

Determinants of Schizophrenia Endophenotypes Based on Neuroimaging and Biochemical Parameters

Despite extensive research, there is no convincing evidence of a reliable diagnostic biomarker for schizophrenia beyond clinical observation. Disorders of glutamatergic neurotransmission associated with N-methyl-D-aspartate (NMDA) receptor insufficiency, neuroinflammation, and redox dysregulation are the principal common mechanism linking changes in the periphery with the brain, ultimately contributing to the emergence of negative symptoms of schizophrenia that underlie differential diagnosis. The aim of the study was to evaluate the influence of these systems via peripheral and cerebral biochemical indices in relation to the patient's clinical condition. Using neuroimaging diagnostics, we were able to define endophenotypes of schizophrenia based on objective laboratory data that form the basis of a personalized approach to diagnosis and treatment. The two distinguished endophenotypes differed in terms of the quality of life, specific schizophrenia symptoms, and glutamatergic neurotransmission metabolites in the anterior cingulate gyrus. Our results, as well as further studies of the excitatory or inhibitory balance of microcircuits, relating the redox systems on the periphery with the distant regions of the brain might allow for predicting potential biomarkers of neuropsychiatric diseases, including schizophrenia. To the best of our knowledge, our study is the first to identify an objective molecular biomarker of schizophrenia outcome.

Assessment of Appetite-Regulating Hormones Provides Further Evidence of Altered Adipoinsular Axis in Early Psychosis

It has been found that antipsychotic-naïve patients with first-episode psychosis (FEP) present with impaired hormonal regulation of appetite in terms of low leptin and high insulin levels (the adipoinsular axis). These findings imply that certain intrinsic mechanisms might play a role in the development of metabolic dysregulation in early psychosis. However, clinical correlates of this phenomenon remain unknown. Moreover, these alterations have not been tested in individuals at familial high risk of psychosis (FHR-P). In this study we aimed to assess the levels of adiponectin, insulin, leptin, glucose, total cholesterol, lipoproteins and triglycerides in FEP patients, unaffected offspring of schizophrenia patients (FHR-P individuals) and healthy controls (HCs) with respect to cognitive performance and psychopathological manifestation. Participants were 35 FEP patients, 33 FHR-P individuals, and 32 HCs. Cognitive performance was assessed using the Repeatable Battery for Assessment of Neuropsychological Status (RBANS). The levels of leptin and high-density lipoproteins (HDL) were significantly lower (leptin: 10.7 ± 15.7 vs. 12.6 ± 10.1, p = 0.046, and HDL: 48.0 ± 16.9 vs. 59.8 ± 17.5 mg/dl, p = 0.007), while the levels of triglycerides and insulin were significantly higher (triglycerides: 137.4 ± 58.8 vs. 77.5 ± 33.2 mg/dl, p < 0.001, and insulin: 15.2 ± 13.1 vs. 9.6 ± 5.0 µIU/ml, p = 0.023) in FEP patients compared to HCs. These differences were significant after controlling for the effects of potential confounding factors. No significant differences in the levels of serum markers between FHR-P individuals and HCs were found. There was a significant negative correlation between the level of leptin and the RBANS language score after covarying for potential confounding factors in FEP patients (B = -0.226, p = 0.006) but not in other subgroups of participants. Our findings confirm impairment of adipoinsular axis in early psychosis. However, results of our study do not support the hypothesis that familial liability to psychosis might be associated with metabolic dysregulation. Leptin levels might be associated with cognitive deficits in FEP patients. Longitudinal studies of individuals at risk of psychosis are needed to provide insights into causal mechanisms underlying our results.

The Role of Adiponectin in the Pathogenesis of Metabolic Disturbances in Patients With Schizophrenia

Antipsychotic-induced metabolic disturbance is a common adverse event occurring in patients treated with antipsychotic drugs. The mechanisms underlying metabolic dysregulation are complex, involving various neurochemical and hormonal systems, the interaction of genetic and lifestyle risk factors, and the antipsychotic drug prescribed. Recently, there has been increasing interest in the relationship between antipsychotic-induced metabolic disturbances and body weight regulatory hormones such as adiponectin. Adiponectin, an adipocyte-derived protein related to insulin sensitivity, weight gain, and anti-inflammation, has attracted great attention because of its potential role of being a biomarker to predict cardiovascular and metabolic diseases. Previous studies regarding the effects of antipsychotics on blood adiponectin levels have shown controversial results. Several factors might contribute to those inconsistent results, including different antipsychotic drugs, duration of antipsychotic exposure, age, sex, and ethnicity. Here we summarize the existing evidence on the link between blood adiponectin levels and metabolic disturbances related to antipsychotic drugs in patients with schizophrenia. We further discuss the effects of individual antipsychotics, patients' gender, ethnicity, age, and treatment duration on those relationships. We propose that olanzapine and clozapine might have a time-dependent biphasic effect on blood adiponectin levels in patients with schizophrenia.