The correlation between metabolic syndrome and neurocognitive and social cognitive performance of patients with schizophrenia

The Optimal Dosage and Duration of Metformin for Prevention and Treatment of Antipsychotic-Induced Weight Gain: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Weight gain and metabolic complications are substantial adverse effects associated with second-generation antipsychotics. However, comprehensive guidelines for managing antipsychotic-induced weight gain are lacking.

METHODS

This review included all double-blind, placebo-controlled studies investigating metformin's effectiveness in addressing antipsychotic-related weight gain. We systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, Google Scholar, and ClinicalTrials.gov for relevant studies from the inception to 2024. A random-effects model was used for the meta-analysis.

RESULTS

This meta-analysis, including 20 studies with 1070 patients, revealed that metformin significantly surpassed placebo in attenuating weight gain in patients receiving antipsychotics. The mean weight change with metformin was -3.32 kg [95% confidence interval (CI): -4.57 to -2.07]. Additionally, metformin use resulted in a marked decrease in body mass index [-1.24 kg/m2 (95% CI: -1.70 to -0.77)]. Metformin could maintain the effects from 12 to 24 weeks.

CONCLUSIONS

This updated meta-analysis investigated the durations and dosages of metformin use in patients with schizophrenia experiencing antipsychotic-induced weight gain. The findings highlight the need for additional large-scale research to validate our findings.

Global Prevalence of Metabolic Syndrome in Schizophrenia Patients: A Systematic Review and Meta-Analysis

The prevalence of metabolic syndrome in patients with schizophrenia has significantly increased and can be associated with severe complications such as chronic diseases and mortality. Despite numerous studies, a comprehensive estimate of the prevalence of metabolic syndrome in schizophrenia patients is lacking. Therefore, this study aimed to estimate the global prevalence of metabolic syndrome in schizophrenia patients through a systematic review and meta-analysis. This study was conducted as a systematic review and meta-analysis based on PRISMA guidelines without time restrictions until April 1, 2024. Relevant articles were identified through searches in databases including Scopus, Web of Science (WoS), PubMed, Science Direct, Embase, and Google Scholar, using key terms combined with AND & OR operators. After removing duplicates and conducting primary and secondary screening, 12 studies were included in the meta-analysis. Data were analysed using the random-effects model in Comprehensive Meta-Analysis Version 2 software. This analysis included 12 studies with 1,953 participants. The pooled prevalence of metabolic syndrome was 41.3% (95% CI: 28.8-55.1), with significant heterogeneity (I2: 96.3%). The highest prevalence was reported in France (79.1%) and the lowest in China (18.03%). Over one-third of patients with schizophrenia are affected by metabolic syndrome. Hence, greater attention should be paid to the prevention and reduction of complications and mortality associated with metabolic syndrome in schizophrenia patients.

Exploring the relationship between lipid metabolism and cognition in individuals living with stable-phase Schizophrenia: a small cross-sectional study using Olink proteomics analysis

BACKGROUND

Cognitive impairment is a core symptom of schizophrenia. Metabolic abnormalities impact cognition, and although the influence of blood lipids on cognition has been documented, it remains unclear. We conducted a small cross-sectional study to investigate the relationship between blood lipids and cognition in patients with stable-phase schizophrenia. Using Olink proteomics, we explored the potential mechanisms through which blood lipids might affect cognition from an inflammatory perspective.

METHODS

A total of 107 patients with stable-phase schizophrenia and cognitive impairment were strictly included. Comprehensive data collection included basic patient information, blood glucose, blood lipids, and body mass index. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and the MATRICS Consensus Cognitive Battery (MCCB). After controlling for confounding factors, we identified differential metabolic indicators between patients with mild and severe cognitive impairment and conducted correlation and regression analyses. Furthermore, we matched two small sample groups of patients with lipid metabolism abnormalities and used Olink proteomics to analyze inflammation-related differential proteins, aiming to further explore the association between lipid metabolism abnormalities and cognition.

RESULTS

The proportion of patients with severe cognitive impairment (SCI) was 34.58%. Compared to patients with mild cognitive impairment (MCI), those with SCI performed worse in the Attention/Alertness (t = 2.668, p = 0.009) and Working Memory (t = 2.496, p = 0.014) cognitive dimensions. Blood lipid metabolism indicators were correlated with cognitive function, specifically showing that higher levels of TG (r = -0.447, p < 0.001), TC (r = -0.307, p = 0.002), and LDL-C (r = -0.607, p < 0.001) were associated with poorer overall cognitive function. Further regression analysis indicated that TG (OR = 5.578, P = 0.003) and LDL-C (OR = 5.425, P = 0.001) may be risk factors for exacerbating cognitive impairment in individuals with stable-phase schizophrenia. Proteomics analysis revealed that, compared to individuals with stable-phase schizophrenia and normal lipid metabolism, those with hyperlipidemia had elevated levels of 10 inflammatory proteins and decreased levels of 2 inflammatory proteins in plasma, with these changes correlating with cognitive function. The differential proteins were primarily involved in pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, and IL-17 signaling pathway.

CONCLUSION

Blood lipids are associated with cognitive function in individuals with stable-phase schizophrenia, with higher levels of TG, TC, and LDL-C correlating with poorer overall cognitive performance. TG and LDL-C may be risk factors for exacerbating cognitive impairment in these patients. From an inflammatory perspective, lipid metabolism abnormalities might influence cognition by activating or downregulating related proteins, or through pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, and IL-17 signaling pathway.

Glymphatic System Dysfunction Underlying Schizophrenia Is Associated With Cognitive Impairment

BACKGROUND AND HYPOTHESIS

Despite the well-documented structural and functional brain changes in schizophrenia, the potential role of glymphatic dysfunction remains largely unexplored. This study investigates the glymphatic system's function in schizophrenia, utilizing diffusion tensor imaging (DTI) to analyze water diffusion along the perivascular space (ALPS), and examines its correlation with clinical symptoms.

STUDY DESIGN

A cohort consisting of 43 people with schizophrenia and 108 healthy controls was examined. We quantified water diffusion metrics along the x-, y-, and z-axis in both projection and association fibers to derive the DTI-ALPS index, a proxy for glymphatic activity. The differences in the ALPS index between groups were analyzed using a 2-way ANCOVA controlling for age and sex, while partial correlations assessed the association between the ALPS index and clinical variables.

STUDY RESULTS

People with schizophrenia showed a significantly reduced DTI-ALPS index across the whole brain and within both hemispheres (F = 9.001, P = .011; F = 10.024, P = .011; F = 5.927, P = .044; false discovery rate corrected), indicating potential glymphatic dysfunction in schizophrenia. The group by cognitive performance interaction effects on the ALPS index were not observed. Moreover, a lower ALPS index was associated with poorer cognitive performance on specific neuropsychological tests in people with schizophrenia.

CONCLUSION

Our study highlights a lower ALPS index in schizophrenia, correlated with more pronounced cognitive impairments. This suggests that glymphatic dysfunction may contribute to the pathophysiology of schizophrenia, offering new insights into its underlying mechanisms.

Right superior frontal gyrus: A potential neuroimaging biomarker for predicting short-term efficacy in schizophrenia

Antipsychotic drug treatment for schizophrenia (SZ) can alter brain structure and function, but it is unclear if specific regional changes are associated with treatment outcome. Therefore, we examined the effects of antipsychotic drug treatment on regional grey matter (GM) density, white matter (WM) density, and functional connectivity (FC) as well as associations between regional changes and treatment efficacy. SZ patients (n = 163) and health controls (HCs) (n = 131) were examined by structural magnetic resonance imaging (sMRI) at baseline, and a subset of SZ patients (n = 77) were re-examined after 8 weeks of second-generation antipsychotic treatment to assess changes in regional GM and WM density. In addition, 88 SZ patients and 81 HCs were examined by resting-state functional MRI (rs-fMRI) at baseline and the patients were re-examined post-treatment to examine FC changes. The Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery (MCCB) were applied to measure psychiatric symptoms and cognitive impairments in SZ. SZ patients were then stratified into response and non-response groups according to PANSS score change (≥50 % decrease or <50 % decrease, respectively). The GM density of the right cingulate gyrus, WM density of the right superior frontal gyrus (SFG) plus 5 other WM tracts were reduced in the response group compared to the non-response group. The FC values between the right anterior cingulate and paracingulate gyrus and left thalamus were reduced in the entire SZ group (n = 88) after treatment, while FC between the right inferior temporal gyrus (ITG) and right medial superior frontal gyrus (SFGmed) was increased in the response group. There were no significant changes in regional FC among the non-response group after treatment and no correlations with symptom or cognition test scores. These findings suggest that the right SFG is a critical target of antipsychotic drugs and that WM density and FC alterations within this region could be used as potential indicators in predicting the treatment outcome of antipsychotics of SZ.

Metabolic Syndrome Causing Cognitive Impairment in Patients With Schizophrenia: A Systematic Review

Schizophrenia often exhibits characteristics like cognitive deficits, and individuals with the condition are at a higher risk of developing metabolic syndrome. The effect of metabolic syndrome on schizophrenia-related cognitive impairment is still unknown, though. This systematic review aims to investigate the association between metabolic syndrome and cognitive impairment in patients with schizophrenia, specifically focusing on neurocognitive and social cognitive performance. Schizophrenia significantly strains the public healthcare system since it necessitates tremendous resources and care to support those suffering from the condition. Furthermore, patients with schizophrenia are more susceptible to developing obesity than the general population, leading to a higher possibility of developing metabolic syndrome. The gut microbiota has been recognized as a critical regulator of bidirectional interactions between the central nervous system and the gastrointestinal tract. Emerging evidence suggests that dysbiosis of the gut microbiota is closely linked to the development of both schizophrenia and obesity, sharing common pathophysiological mechanisms, particularly immune inflammation. In this systematic review, we examine the existing literature to explore the relationship between metabolic syndrome and cognitive impairment in individuals with schizophrenia. By synthesizing available evidence on neurocognitive and social cognitive performance, we aim to provide a comprehensive understanding of the association between metabolic syndrome and cognitive deficits in schizophrenia. The findings from this review will contribute to our knowledge of the complex interplay between metabolic abnormalities, gut microbiota dysbiosis, and cognitive impairments in patients with schizophrenia. This understanding may facilitate the development of novel interventions targeting metabolic syndrome as a potential avenue for improving cognitive outcomes in individuals with schizophrenia.

Analysis of metabolic syndrome and cognitive functional analysis in schizophrenic patients based on psychological intervention

In this paper, we explore the characteristics of cognitive dysfunction in patients with schizophrenia complicated with metabolic syndrome (MS), and to explore the effects of psychological intervention on MS and cognitive function changes in patients with schizophrenia, and to provide theoretical basis for early intervention of MS. 159 patients with schizophrenia were retrospectively analyzed and divided into 2 groups according to whether they were accompanied by MS. (41 cases), the second group was not MS. (118 cases). Results shows PANSS total score as (53.72 ± 5.03), positive symptom score (12.39 ± 2.68), negative symptom score (14.94 ± 3.27), general pathological score (26.27 ± 3.63). In MS group,Verbal fluency (16.69 ± 1.27), symbol coding (30.46 ± 2.55), number sequence (15.21 ± 1.84), spatial span (10.14 ± 0.68), continuous operation (16.72 ± 1.34), verbal memory (16.72 ± 1.34), and visual memory (14.24 ± 1.26), all indicators were significantly lower than those of non-MS group. The cognitive impairment of schizophrenia patients with multiple sclerosis is more severe than that of schizophrenia patients without multiple sclerosis. Increasing psychological intervention can effectively improve the therapeutic effect and cognitive function of schizophrenia patients. Early identification and intervention of MS in the clinical treatment of schizophrenia is particularly important.

Schizophrenia and obesity: May the gut microbiota serve as a link for the pathogenesis?

Schizophrenia (SZ) places a tremendous burden on public health as one of the leading causes of disability and death. SZ patients are more prone to developing obesity than the general population from the clinical practice. The development of obesity frequently causes poor psychiatric outcomes in SZ patients. In turn, maternal obesity during pregnancy has been associated with an increased risk of SZ in offspring, suggesting that these two disorders may have shared neuropathological mechanisms. The gut microbiota is well known to serve as a major regulator of bidirectional interactions between the central nervous system and the gastrointestinal tract. It also plays a critical role in maintaining physical and mental health in humans. Recent studies have shown that the dysbiosis of gut microbiota is intimately associated with the onset of SZ and obesity through shared pathophysiological mechanisms, particularly the stimulation of immune inflammation. Therefore, gut microbiota may serve as a common biological basis for the etiology in both SZ and obesity, and the perturbed gut-brain axis may therefore account for the high prevalence of obesity in patients with SZ. On the basis of these findings, this review provides updated perspectives and intervention approaches on the etiology, prevention, and management of obesity in SZ patients by summarizing the recent findings on the role of gut microbiota in the pathogenesis of SZ and obesity, highlighting the role of gut-derived inflammation.

Associations between metabolic disorders and sleep disturbance in patients with schizophrenia

BACKGROUND

Sleep disturbance plays a crucial role in mental illness and metabolic dysregulation. However, the clinical correlates of metabolic disorders (MD, only meeting 1 or 2 metabolic syndrome standards) and its relationship to sleep disturbance in patients with schizophrenia are uncertain. The study was to illuminate the association between MD and sleep disturbance in patients with schizophrenia.

METHODS

One hundred and sixty-four patients with schizophrenia (157 drug-naive and 7 drug-free) were classified into 2 groups: MD and non-MD. The Pittsburgh Sleep Quality Index (PSQI) and the Positive and Negative Symptom Scale (PANSS) were employed to assess sleep quality and clinical symptoms. Weight, height, waistline, blood pressure, fasting glucose, and lipid metabolic levels were recorded.

RESULTS

Sleep disturbance was more pronounced in the MD group compared to the non-MD group, including subjective sleep quality (z = -4.074, p = 0.000), sleep latency (z = -3.867, p = 0.000), sleep duration (z = -2.471, p = 0.013) and total scores (z = -3.074, p = 0.002). After controlling for confounding factors including age, sex, body mass index, smoking, marital status, and duration of illness, binary logistics regression showed that subjective sleep quality (p = 0.034) and sleep latency (p = 0.034) were significant independent predictors of MD. Further, partial correlation analysis showed that sleep latency (r = -0.200, p = 0.011) was significantly negatively correlated with HDLC.

CONCLUSION

Our study suggests a high rate of MD in patients with schizophrenia, most of who were drug-naive, in a Chinese population. Longer sleep latency is associated with MD in schizophrenia patients, suggesting an important role of sleep disturbance in the development of MD in patients with schizophrenia. Interventions to improve sleep quality may prevent MD in patients with schizophrenia at an early stage.

Metabolic disturbances, hemoglobin A1c, and social cognition impairment in Schizophrenia spectrum disorders

Social cognitive impairments are core features of schizophrenia spectrum disorders (SSD) and are associated with greater functional impairment and decreased quality of life. Metabolic disturbances have been related to greater impairment in general neurocognition, but their relationship to social cognition has not been previously reported. In this study, metabolic measures and social cognition were assessed in 245 participants with SSD and 165 healthy comparison subjects (HC), excluding those with hemoglobin A1c (HbA1c) > 6.5%. Tasks assessed emotion processing, theory of mind, and social perception. Functional connectivity within and between social cognitive networks was measured during a naturalistic social task. Among SSD, a significant inverse relationship was found between social cognition and cumulative metabolic burden (β = -0.38, p < 0.001) and HbA1c (β = -0.37, p < 0.001). The relationship between social cognition and HbA1c was robust across domains and measures of social cognition and after accounting for age, sex, race, non-social neurocognition, hospitalization, and treatment with different antipsychotic medications. Negative connectivity between affect sharing and motor resonance networks was a partial mediator of this relationship across SSD and HC groups (β = -0.05, p = 0.008). There was a group x HbA1c effect indicating that SSD participants were more adversely affected by increasing HbA1c. Thus, we provide the first report of a robust relationship in SSD between social cognition and abnormal glucose metabolism. If replicated and found to be causal, insulin sensitivity and blood glucose may present as promising targets for improving social cognition, functional outcomes, and quality of life in SSD.

Cariprazine's Potential in Improving Social Dysfunction in Patients With Schizophrenia: A Perspective

Social dysfunction is one of the most debilitating aspects of schizophrenia. Treatment of this complex phenomenon, constituted by negative, cognitive, and affective symptoms, has been difficult with the available pharmacological agents, hence it represents an unmet medical need. Cariprazine, a novel, third-generation antipsychotic with a unique mechanism of action has been proven to sufficiently alleviate negative, cognitive, and affective symptoms of schizophrenia. These characteristics make this compound a valid candidate for addressing social dysfunction too. In this perspective, we argue that cariprazine can be viewed as a "socializing drug" that has the ability to improve the patient's functionality and ultimately their quality of life. Data from animal research, clinical trials, an observational study, and patient cases are provided.

The Relation between the Plasma Concentrations of Long-Acting Atypical Antipsychotics and Clinical Effectiveness in Patients Affected by Schizophrenia or Schizoaffective Disorder: A Comprehensive Overview

Atypical antipsychotic depot medications are currently recommended for patients with schizophrenia (SCZ) to prevent relapse and ameliorate the long-term prognosis of these patients. This review critically summarizes the available data about the association between the plasma concentrations of long-acting Second- Generation Antipsychotics (SGAs) and the clinical effectiveness of these compounds in patients affected by SCZ or schizoaffective disorder. Our question is if the measurement of these concentrations can be helpful for clinicians in predicting treatment response and clinical stabilization of patients. Bibliographic research on the main databases was performed, and 13 studies were finally included in this review. Contrasting results were found between plasma concentrations of long-acting injectable (LAI) risperidone and clinical amelioration according to rating scale scores. Data are too scanty to draw conclusions for olanzapine and paliperidone. In contrast, despite small sample sizes, data are quite concordant in showing a relation between long-acting SGA plasma concentrations and D2 receptor occupancy. Despite the preliminary encouraging results, particularly for D2 receptor occupancy, future research with larger samples will have to confirm the clinical usefulness of measuring LAI SGA plasma concentrations to predict the clinical response of patients affected by severe mental conditions such as SCZ.