Mechanisms Underlying the Comorbidity of Schizophrenia and Type 2 Diabetes Mellitus

Integrating Electronic Health Records and Polygenic Risk to Identify Genetically Unrelated Comorbidities of Schizophrenia That May Be Modifiable

Background

Patients with schizophrenia have substantial comorbidity that contributes to reduced life expectancy of 10 to 20 years. Identifying modifiable comorbidities could improve rates of premature mortality. Conditions that frequently co-occur but lack shared genetic risk with schizophrenia are more likely to be products of treatment, behavior, or environmental factors and therefore are enriched for potentially modifiable associations.

Methods

Phenome-wide comorbidity was calculated from electronic health records of 250,000 patients across 2 independent health care institutions (Vanderbilt University Medical Center and Mass General Brigham); associations with schizophrenia polygenic risk scores were calculated across the same phenotypes in linked biobanks.

Results

Schizophrenia comorbidity was significantly correlated across institutions (r = 0.85), and the 77 identified comorbidities were consistent with prior literature. Overall, comorbidity and polygenic risk score associations were significantly correlated (r = 0.55, p = 1.29 × 10-118). However, directly testing for the absence of genetic effects identified 36 comorbidities that had significantly equivalent schizophrenia polygenic risk score distributions between cases and controls. This set included phenotypes known to be consequences of antipsychotic medications (e.g., movement disorders) or of the disease such as reduced hygiene (e.g., diseases of the nail), thereby validating the approach. It also highlighted phenotypes with less clear causal relationships and minimal genetic effects such as tobacco use disorder and diabetes.

Conclusions

This work demonstrates the consistency and robustness of electronic health record-based schizophrenia comorbidities across independent institutions and with the existing literature. It identifies known and novel comorbidities with an absence of shared genetic risk, indicating other causes that may be modifiable and where further study of causal pathways could improve outcomes for patients.

A network of transcriptomic signatures identifies novel comorbidity mechanisms between schizophrenia and somatic disorders

The clinical burden of mental illness, in particular schizophrenia and bipolar disorder, are driven by frequent chronic courses and increased mortality, as well as the risk for comorbid conditions such as cardiovascular disease and type 2 diabetes. Evidence suggests an overlap of molecular pathways between psychotic disorders and somatic comorbidities. In this study, we developed a computational framework to perform comorbidity modeling via an improved integrative unsupervised machine learning approach based on multi-rank non-negative matrix factorization (mrNMF). Using this procedure, we extracted molecular signatures potentially explaining shared comorbidity mechanisms. For this, 27 case-control microarray transcriptomic datasets across multiple tissues were collected, covering three main categories of conditions including psychotic disorders, cardiovascular diseases and type II diabetes. We addressed the limitation of normal NMF for parameter selection by introducing multi-rank ensembled NMF to identify signatures under various hierarchical levels simultaneously. Analysis of comorbidity signature pairs was performed to identify several potential mechanisms involving activation of inflammatory response auxiliarily interconnecting angiogenesis, oxidative response and GABAergic neuro-action. Overall, we proposed a general cross-cohorts computing workflow for investigating the comorbid pattern across multiple symptoms, applied it to the real-data comorbidity study on schizophrenia, and further discussed the potential for future application of the approach.

The volume of gray matter mediates the relationship between glucolipid metabolism and neurocognition in first-episode, drug-naïve patients with schizophrenia

We aimed to examine the hypotheses that glucolipid metabolism is linked to neurocognition and gray matter volume (GMV) and that GMV mediates the association of glucolipid metabolism with neurocognition in first-episode, drug-naïve (FEDN) patients with schizophrenia. Parameters of glucolipid metabolism, neurocognition, and magnetic resonance imaging were assessed in 63 patients and 31 controls. Compared to controls, patients exhibited higher levels of fasting glucose, triglyceride, and insulin resistance index, lower levels of cholesterol and high-density lipoprotein cholesterol, poorer neurocognitive functions, and decreased GMV in the bilateral insula, left middle occipital gyrus, and left postcentral gyrus. In the patient group, triglyceride levels and the insulin resistance index exhibited a negative correlation with Rapid Visual Information Processing (RVP) mean latency, a measure of attention within the Cambridge Neurocognitive Test Automated Battery (CANTAB), while showing a positive association with GMV in the right insula. The mediation model revealed that triglyceride and insulin resistance index had a significant positive indirect (mediated) influence on RVP mean latency through GMV in the right insula. Glucolipid metabolism was linked to both neurocognitive functions and GMV in FEDN patients with schizophrenia, with the effect pattern differing from that observed in chronic schizophrenia or schizophrenia comorbid with metabolic syndrome. Moreover, glucolipid metabolism might indirectly contribute to neurocognitive deficits through the mediating role of GMV in these patients.

Efficacy and Safety of Insulin Degludec/Insulin Aspart versus Biphasic Insulin Aspart 30 in Patients with Type 2 Diabetes: A Meta-Analysis of Randomized Controlled Trials

Background

We systematically reviewed and analyzed the efficacy and safety of insulin degludec/insulin as-part (IDegAsp) versus biphasic insulin aspart 30 (BIAsp 30) in patients with type 2 diabetes (T2D).

Methods

We used computers to search the Embase, PubMed, Clinical Trials, and the Cochrane Library database, and collected randomized controlled trials (RCTs) on the treatment of IDegAsp versus BIAsp 30 in T2D patients. The research period was from the establishment of the database to May 19, 2023. We used Review Manager 5.20 statistical software for systematic meta-analysis.

Results

We included 8 RCTs with 2281 participants. IDegAsp was better to BIAsp30 in improving fasting plasma glucose (FPG) levels (P<0.001) and reducing the endpoint daily average insulin dose (P<0.01). Furthermore, compared with BIAsp30, IDegAsp significantly reduced the risk of nocturnal hypoglycemic events (P<0.001). However, there was no significant difference in the improvement of body weight change (P=0.99), glycosylated hemoglobin (P=0.50), the overall risk of hypoglycemic events (P=0.57) and adverse events (P=0.89) between the two groups.

Conclusion

Compared with BIAsp30, IDegAsp could significantly reduce FPG levels, insulin dosage, and the risk of nocturnal hypoglycemic events in T2D patients, without increasing the overall risk of adverse events.

Cognitive deficits among people with schizophrenia and prediabetes or diabetes

INTRODUCTION

Both type 2 diabetes mellitus (T2DM) and schizophrenia are known to be associated with cognitive deficits. The impact of the comorbidities of T2DM or prediabetes (PD) on cognition among people with schizophrenia has been poorly researched. We evaluated the cognitive functioning of patients with schizophrenia and PD or T2DM and compared them to patients with schizophrenia with normal blood sugar.

METHODS

We retrospectively collated data on cognition, fasting blood glucose (FBG), lipids and other selected demographic and clinical variables of 171 patients with schizophrenia and 16 patients with schizoaffective disorder who were admitted to an inpatient rehabilitation facility in Western Australia from 2011 to 2018. The Brief Assessment of Cognition in Schizophrenia (BACS) was used to evaluate cognitive functioning. Parametric and non-parametric analyses were used to examine the study's aims.

RESULTS

Sixty-six percent of the patients had normal blood sugar, 25% had PD and 9% had T2DM. The BACS composite score revealed an increasing gradient of cognitive deficits, ranging from mild to severe, between the normal, PD and T2DM groups, respectively. The T2DM group had a significantly lower composite score compared with the PD (p = 0.026) and normal groups (p < 0.001). On the BACS subtests, the scores of T2DM and PD patients were similar except for the token motor task, in which the T2DM group had significantly lower scores (p < 0.001). The T2DM group also had lower scores on the subtests of BACS, except memory tests, compared with those with normal blood sugar. There was no significant difference in the composite and subtest cognitive scores between the PD and normal groups.

CONCLUSIONS

Our study revealed more pronounced cognitive deficits among patients with schizophrenia and dysglycaemia, particularly those with T2DM, compared with those with schizophrenia with normal blood sugar.

Amisulpride as the antipsychotic of choice in severe psychotic disorder with comorbid impaired glucose tolerance

Antipsychotics are the mainstay treatment for the majority of severe mental illnesses. Such patients are also more prone to develop medical comorbidities, which complicate the treatment decisions. It is estimated that up to 40% of individuals with schizophrenia have impaired glucose tolerance (IGT) or diabetes, which can be attributed to a combination of genetic, lifestyle, and medication-related factors. Some widely used antipsychotic medications like olanzapine, risperidone, and clozapine have been associated with an increased risk of weight gain, insulin resistance, and other metabolic abnormalities, which can worsen IGT and increase the risk of developing diabetes. Among second-generation antipsychotics (SGAs), amisulpride, aripirazole, and ziprasidone have a fairly low potency to cause obesity and hyperglycemia. In this context, clinicians must balance the benefits and risks of different antipsychotic medications and consider the individual's specific needs and preferences. Here, we shall discuss three cases, to ascertain how the use of amisulpride helped in glycemic control, and also reflect on probable etiologies leading to deranged glucose levels.

Physical health monitoring for people with schizophrenia

Schizophrenia is a severe psychiatric disorder associated with significant comorbidities and early mortality. People with schizophrenia have a greater predisposition to the top 6 modifiable global mortality (cardiometabolic) risk factors as defined by the World Health Organization (compared with the general population). These are driven by genetic, lifestyle and disease factors, and obesogenic antipsychotic medications. Smoking, obesity and type 2 diabetes are the most important modifiable cardiometabolic risk factors for cardiovascular disease in people with schizophrenia. Enhanced physical health screening, especially for cardiometabolic risk factors, is recommended for people with schizophrenia. A multidisciplinary holistic approach is recommended for treating people with schizophrenia, using contact with primary care practitioners to review their physical health.

Women with Schizophrenia Have Difficulty Maintaining Healthy Diets for Themselves and Their Children: A Narrative Review

Severe psychiatric disorders such as schizophrenia are inevitably linked to unemployment, meagre per capita income, and residence in disadvantaged, poorly resourced neighbourhoods. This means difficult access to healthy food and is particularly problematic for pregnant women and mothers with children to feed. The necessity of taking antipsychotic drugs is an additional barrier to healthy eating because these drugs are associated with serious cognitive, psychological, behavioural, and metabolic sequelae. Being ill with psychosis makes it extremely difficult to maintain a healthy diet; nutritional deficiencies result, as do medical complications. The results of present literature review confirm the gravity of the problem and suggest a number of potentially useful clinical interventions.

Involvement of the Receptor for Advanced Glycation End Products (RAGE) in high fat-high sugar diet-induced anhedonia in rats

Clinical and basic science investigation indicates a link between insulin resistance and anhedonia. Previous results of this laboratory point to impaired nucleus accumbens (NAc) insulin signaling as an underpinning of diet-induced anhedonia, based on use of a glucose lick microstructure assay. The present study evaluated whether advanced glycation end products (AGEs) and their receptor (RAGE), known to mediate obesogenic diet-induced inflammation and pathological metabolic conditions, are involved in this behavioral change. Six weeks maintenance of male and female rats on a high fat-high sugar liquid diet (chocolate Ensure) increased body weight gain, and markedly increased circulating insulin and leptin, but induced anhedonia (decreased first minute lick rate and lick burst size) in males only. In these subjects, anhedonia correlated with plasma concentrations of insulin. Although the diet did not alter plasma or NAc AGEs, or the expression of RAGE in the NAc, marginally significant correlations were seen between anhedonia and plasma content of several AGEs and NAc RAGE. Importantly, a small molecule RAGE antagonist, RAGE229, administered twice daily by oral gavage, prevented diet-induced anhedonia. This beneficial effect was associated with improved adipose function, reflected in the adiponectin/leptin ratio, and increased pCREB/total CREB in the NAc, and a shift in the pCREB correlation with pThr34-DARPP-32 from near-zero to strongly positive, such that both phospho-proteins correlated with the rescued hedonic response. This set of findings suggests that the receptor/signaling pathway and cell type underlying the RAGE229-mediated increase in pCREB may mediate anhedonia and its prevention. The possible role of adipose tissue as a locus of diet-induced RAGE signaling, and source of circulating factors that target NAc to modify hedonic reactivity are discussed.

Genomic and Reverse Translational Analysis Discloses a Role for Small GTPase RhoA Signaling in the Pathogenesis of Schizophrenia: Rho-Kinase as a Novel Drug Target

Schizophrenia is one of the most serious psychiatric disorders and is characterized by reductions in both brain volume and spine density in the frontal cortex. RhoA belongs to the RAS homolog (Rho) family and plays critical roles in neuronal development and structural plasticity via Rho-kinase. RhoA activity is regulated by GTPase-activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs). Several variants in GAPs and GEFs associated with RhoA have been reported to be significantly associated with schizophrenia. Moreover, several mouse models carrying schizophrenia-associated gene variants involved in RhoA/Rho-kinase signaling have been developed. In this review, we summarize clinical evidence showing that variants in genes regulating RhoA activity are associated with schizophrenia. In the last half of the review, we discuss preclinical evidence indicating that RhoA/Rho-kinase is a potential therapeutic target of schizophrenia. In particular, Rho-kinase inhibitors exhibit anti-psychotic-like effects not only in Arhgap10 S490P/NHEJ mice, but also in pharmacologic models of schizophrenia (methamphetamine- and MK-801-treated mice). Accordingly, we propose that Rho-kinase inhibitors may have antipsychotic effects and reduce cognitive deficits in schizophrenia despite the presence or absence of genetic variants in small GTPase signaling pathways.

Genomic insights into the comorbidity between type 2 diabetes and schizophrenia

Multimorbidity represents an increasingly important public health challenge with far-reaching implications for health management and policy. Mental health and metabolic diseases have a well-established epidemiological association. In this study, we investigate the genetic intersection between type 2 diabetes and schizophrenia. We use Mendelian randomization to examine potential causal relationships between the two conditions and related endophenotypes. We report no compelling evidence that type 2 diabetes genetic liability potentially causally influences schizophrenia risk and vice versa. Our findings show that increased body mass index (BMI) has a protective effect against schizophrenia, in contrast to the well-known risk-increasing effect of BMI on type 2 diabetes risk. We identify evidence of colocalization of association signals for these two conditions at 11 genomic loci, six of which have opposing directions of effect for type 2 diabetes and schizophrenia. To elucidate these colocalizing signals, we integrate multi-omics data from bulk and single-cell gene expression studies, along with functional information. We identify high-confidence effector genes and find that they are enriched for homeostasis and lipid-related pathways. We also highlight drug repurposing opportunities including N-methyl-D-aspartate (NMDA) receptor antagonists. Our findings provide insights into shared biological mechanisms for type 2 diabetes and schizophrenia, highlighting common factors that influence the risk of the two conditions in opposite directions and shedding light on the complex nature of this comorbidity.

Paraoxonase/Arylesterase Activity of Serum Paraoxonase-1 and Schizophrenia: A Systematic Review and Meta-Analysis

The presence of a pro-oxidant state in patients with schizophrenia may account for the increased risk of atherosclerosis and cardiovascular disease in this group and supports the potential utility of circulating biomarkers of oxidative stress for risk stratification and management. We investigated this issue by conducting a systematic review and meta-analysis of the association between the circulating concentrations of paraoxonase-1, an antioxidant calcium-dependent high-density lipoprotein (HDL)-associated esterase, with paraoxonase and arylesterase activity in schizophrenia. We searched electronic databases from inception to 31 May 2023 for studies investigating paraoxonase-1 in patients with schizophrenia and healthy controls and assessed the risk of bias and the certainty of evidence (PROSPERO registration number: CRD42023435442). Thirteen studies were identified for analysis. There were no significant between-group differences in paraoxonase (standard mean difference, SMD = 0.12, 95% CI -0.23 to 0.48, p = 0.50; extremely low certainty of evidence) or arylesterase activity (SMD = -0.08, 95% CI -0.39 to 0.23, p = 0.61; very low certainty of evidence). However, in meta-regression and subgroup analysis we observed significant associations between the SMD of paraoxonase and age (p = 0.003), HDL-cholesterol (p = 0.029), and study country (p = 0.04), and the SMD of arylesterase and age (p = 0.007), body mass index (p = 0.012), HDL-cholesterol (p = 0.002), and pharmacological treatment for schizophrenia (p < 0.001). In the absence of overall between-group differences, our systematic review and meta-analysis suggests that alterations in paraoxonase-1 may reflect a pro-oxidant state in specific subgroups of patients with schizophrenia that require further assessment in appropriately designed studies.

Exosome and exosomal contents in schizophrenia

Schizophrenia (SCZ) is a severe mental disorder that affects approximately 1% general population worldwide and poses a considerable burden to society. Despite decades of research, its etiology remains unclear, and diagnosis remains challenging due to its heterogeneous symptoms. Exosomes play a crucial role in intercellular communication, and their contents, including nucleotides, proteins and metabolites, have been linked to various diseases. Recent studies have implicated exosome abnormalities in the pathogenesis of schizophrenia. In this review, we discuss the current understanding of the relationship between exosomes and schizophrenia, focusing on the role of exosomal contents in this disease. We summarize recent findings and provide insights into the potential use of exosomes as biomarkers for the diagnosis and treatment of schizophrenia.

Therapeutic management of atypical antipsychotic‑related metabolic dysfunctions using GLP‑1 receptor agonists: A systematic review

Metabolic disorders (MDs) like obesity, dyslipidemia, and type 2 diabetes are more frequently observed in patients diagnosed with psychiatric disorders undergoing treatment with antipsychotics, particularly atypical agents, than in the general population. The second generation of antidiabetics (SGAD) has been associated with cardiovascular benefits in large clinical trials which represent an important advantage over first-generation agents and might be of interest in the psychiatric population where multiple risk factors for cardiovascular disease (e.g., smoking, lack of exercise, and lack of healthy diet) are common occurrences. Therefore, this systematic review focused on the evaluation of the glucagon-like peptide-1 receptor agonists (GLP1-RAs), as a representative of the SGAD, to determine whether these agents may be recommended in patients with psychiatric disorders and MDs. For analysis, three electronic databases and clinical trial registers were explored for papers published between January 2000 and November 2022. After applying the inclusion and exclusion criteria, 20 clinical and preclinical trials, therapeutic guidelines, and meta-analyses were reviewed, and clinical recommendations were formulated. The large majority of the reviewed data (nine papers) were graded 'moderate' based on the GRADE criteria. The efficacy and tolerability of liraglutide and exenatide in the management of antipsychotic-induced MDs were supported by evidence of average quality, while the results regarding other GLP-1RAs were not sufficient to formulate a recommendation for their administration in this specific population. Clozapine and olanzapine had the most negative consequences on body weight, glycemic, and lipid metabolism. Therefore, careful monitoring of metabolic parameters is required when these are prescribed. Liraglutide and exenatide may be recommended as augmentative agents to metformin therapy, especially in patients receiving these two atypical antipsychotics, but most of the reviewed data supported the efficacy of GLP-1RAs only during the treatment administration. The two follow-up studies retrieved in the literature reported modest effects after GLP-1RA discontinuation after 1 year; therefore, long-term monitoring of metabolic parameters is required. More research is needed, and three randomized clinical trials are already ongoing, to evaluate the effects of GLP-1RAs in decreasing body weight, but also on other important metabolic variables, such as HbA1c status, fasting glucose levels, and lipid levels in patients receiving antipsychotic treatment.

Identifying modifiable comorbidities of schizophrenia by integrating electronic health records and polygenic risk

Patients with schizophrenia have substantial comorbidity contributing to reduced life expectancy of 10-20 years. Identifying which comorbidities might be modifiable could improve rates of premature mortality in this population. We hypothesize that conditions that frequently co-occur but lack shared genetic risk with schizophrenia are more likely to be products of treatment, behavior, or environmental factors and therefore potentially modifiable. To test this hypothesis, we calculated phenome-wide comorbidity from electronic health records (EHR) in 250,000 patients in each of two independent health care institutions (Vanderbilt University Medical Center and Mass General Brigham) and association with schizophrenia polygenic risk scores (PRS) across the same phenotypes (phecodes) in linked biobanks. Comorbidity with schizophrenia was significantly correlated across institutions (r = 0.85) and consistent with prior literature. After multiple test correction, there were 77 significant phecodes comorbid with schizophrenia. Overall, comorbidity and PRS association were highly correlated (r = 0.55, p = 1.29×10-118), however, 36 of the EHR identified comorbidities had significantly equivalent schizophrenia PRS distributions between cases and controls. Fifteen of these lacked any PRS association and were enriched for phenotypes known to be side effects of antipsychotic medications (e.g., "movement disorders", "convulsions", "tachycardia") or other schizophrenia related factors such as from smoking ("bronchitis") or reduced hygiene (e.g., "diseases of the nail") highlighting the validity of this approach. Other phenotypes implicated by this approach where the contribution from shared common genetic risk with schizophrenia was minimal included tobacco use disorder, diabetes, and dementia. This work demonstrates the consistency and robustness of EHR-based schizophrenia comorbidities across independent institutions and with the existing literature. It identifies comorbidities with an absence of shared genetic risk indicating other causes that might be more modifiable and where further study of causal pathways could improve outcomes for patients.

The positive association between antipsychotic-induced weight gain and therapeutic response: New biotypes of schizophrenia

Co-occurrence of antipsychotic-induced weight gain (AIWG) and therapeutic response (TR) did exist in clinic but was rarely studied. This study aims to identify potential TR/ AIWG biotypes and explore the clinical, genetic and neuroimaging features. This study enrolled 3030 patients to identify potential TR/AIWG biotypes and explore the clinical, genetic and neuroimaging features. We found three biotypes: TR+nonAIWG (46.91%), TR+AIWG (18.82%), and nonTR+nonAIWG (34.27%). TR+AIWG showed lower weight and lipid level at baseline, but higher changing rate, and higher genetic risk of obesity than TR+nonAIWG and nonTR+nonAIWG. GWAS identified ADIPOQ gene related to TR+AIWG biotypes and top-ranked loci enriched in one-carbon metabolic process, which related to both schizophrenia and metabolic dysfunction. Genetically predicted TR+AIWG was associated with higher odds of diabetes (OR=1.05). The left supplementary motor area was significantly negatively correlated with PRS of obesity. The distinguishing ability with multi-omics data to identify TR+AIWG reached 0.787. In a word, the "thin" patients with a higher risk of obesity are the target population of early intervention.

Integrative analysis to identify shared mechanisms between schizophrenia and bipolar disorder and their comorbidities

Schizophrenia and bipolar disorder are characterized by highly similar neuropsychological signatures, implying shared neurobiological mechanisms between these two disorders. These disorders also have comorbidities, such as type 2 diabetes mellitus (T2DM). To date, an understanding of the mechanisms that mediate the link between these two disorders remains incomplete. In this work, we identify and investigate shared patterns across multiple schizophrenia, bipolar disorder and T2DM gene expression datasets through multiple strategies. Firstly, we investigate dysregulation patterns at the gene-level and compare our findings against disease-specific knowledge graphs (KGs). Secondly, we analyze the concordance of co-expression patterns across datasets to identify disease-specific as well as common pathways. Thirdly, we examine enriched pathways across datasets and disorders to identify common biological mechanisms between them. Lastly, we investigate the correspondence of shared genetic variants between these two disorders and T2DM as well as the disease-specific KGs. In conclusion, our work reveals several shared candidate genes and pathways, particularly those related to the immune system, such as TNF signaling pathway, IL-17 signaling pathway and NF-kappa B signaling pathway and nervous system, such as dopaminergic synapse and GABAergic synapse, which we propose mediate the link between schizophrenia and bipolar disorder and its shared comorbidity, T2DM.

Sex differences in the prevalence and clinical correlates of diabetes in Chinese patients with chronic schizophrenia

Sex differences have been noted in schizophrenia (SCZ) and diabetes mellitus (DM); however, the effect of sex on SCZ patients with DM remains unknown. We aimed to investigate sex differences in the prevalence, demographic and clinical correlates of DM in Chinese patients with chronic SCZ. A total of 988 Han Chinese SCZ patients (male/female: 638/350) were recruited from two psychiatric hospitals in China. We used the Positive and Negative Syndrome Scale (PANSS) to evaluate the psychopathological symptoms of the patients. In addition, serum glucose and lipid levels were assayed. The prevalence of DM in female patients (57/350, 16.29%) was higher than that in male patients (79/638, 12.38%). Binary logistic regression analyses confirmed that the prevalence of DM in female patients was higher than that in male patients (P < 0.001, OR = 4.62, 95% CI = 2.11-10.11). Moreover, female patients had significantly higher positive symptoms than male patients (P = 0.003, OR = 1.08, 95% CI = 1.03-1.14). Further, higher body mass index (BMI) and higher triglyceride (TG) were significantly associated with DM in men (both P < 0.05). Decreased high density lipoprotein (HDL) was significantly associated with DM in both male and female patients (both P < 0.01). Comorbid DM is more common in female SCZ patients, and there are sex-specific correlates of DM in SCZ.

Schizophrenia as a risk factor for cardiovascular and metabolic health outcomes: a comparative risk assessment

AIMS

Cardiometabolic diseases are responsible for the majority of premature deaths in people with schizophrenia. This study aimed to quantify the fatal burden of ischaemic heart disease (IHD), stroke and diabetes attributable to schizophrenia.

METHODS

Comparative Risk Assessment methodology from the Global Burden of Disease (GBD) study was used to calculate attributable burden; pooled relative risks (RRs) for IHD, stroke and diabetes were estimated via meta-regression, which were combined with GBD schizophrenia prevalence estimates to calculate the deaths and years of life lost (YLLs) caused by these health outcomes that were attributable to schizophrenia. The proportion of explained all-cause fatal burden and corresponding unexplained burden was also calculated.

RESULTS

The pooled RRs for IHD, stroke and diabetes mortality were 2.36 [95% uncertainty interval (UI) 1.77 to 3.14], 1.86 (95% UI 1.36 to 2.54) and 4.08 (95% UI 3.80 to 4.38) respectively. Schizophrenia was responsible for around 50 000 deaths and almost 1.5 million YLLs globally in 2019 from these health outcomes combined. IHD, stroke and diabetes together explained around 13% of all deaths and almost 11% of all YLLs attributable to schizophrenia, resulting in 320 660 (95% UI 288 299 to 356 517) unexplained deaths and 12 258 690 (95% UI 10 925 426 to 13 713 646) unexplained YLLs.

CONCLUSIONS

Quantifying the physical disease burden attributable to schizophrenia provides a means of capturing the substantial excess mortality associated with this disorder within the GBD framework, contributing to an important evidence base for healthcare planning and practice.

Effect of H2H management mode on blood sugar control and living ability in patients with schizophrenia and type 2 diabetes mellitus

OBJECTIVE

To explore the effect of H2H management mode on blood sugar control and living ability in patients with schizophrenia and type 2 diabetes mellitus.

METHODS

A retrospective analysis was conducted on 95 patients with schizophrenia and type 2 diabetes who were hospitalized in Wuhan Mental Health Center from July 2021 to February 2022. The subjects were grouped according to management mode: 50 cases in group A (H2H management mode) and 45 cases in group B (conventional mode). Psychiatric symptoms were assessed with the Positive and Negative Symptoms Scale (PANSS), and changes in living ability before and after the intervention were assessed by the activity of daily living scale (ADL). Fasting blood glucose (FPG), 2-h postprandial blood glucose (2hPG), and glycosylated hemoglobin (HbA1c) were detected by high-performance liquid chromatography on a blood glucose analyzer. Schizophrenia Quality of Life Scale (SQLS) was used to evaluate changes in life quality, and Pittsburgh Sleep Quality Index (PSQI) and the Simple Roy Coping Adaptation Scale (CAPS-15) were for the sleep quality and coping adaptability of the two groups before and after intervention, respectively. Self-perceived burden scale (SPBS) was used to evaluate the self-perceived burden of the two groups before and after intervention.

RESULTS

After intervention, PANSS score of group A was observed markedly lower than that of group B, as well as its ADL score, SQLS score and the levels of 2hPG, FPG and HbA1c (all P < 0.05). Compared to group B, the patients in group A were also assessed with evidently lower SQLS score (P < 0.05) and lower scores of physical burden, emotional burden and economic burden after intervention (all P < 0.05).

CONCLUSION

H2H management model can effectively improve the mental state, quality of life, sleep quality and coping adaptability of patients with schizophrenia complicated with type 2 diabetes, as well as reducing patients' blood sugar, which is worthy of clinical promotion.

[Mental disorders and diabetes mellitus (Update 2023)]

Psychiatric disorders and psychological problems are common in patients with diabetes mellitus. There is a twofold increase in depression which is associated with suboptimal glycemic control and increased morbidity and mortality. Other psychiatric disorders with a higher incidence of diabetes are cognitive impairment, dementia, disturbed eating behavior, anxiety disorders, schizophrenia, bipolar disorders and borderline personality disorder. The coincidence of mental disorders and diabetes has unfavorable influences on metabolic control and micro- and macroangiopathic complications. Improvement of therapeutic outcome is a challenge in the modern health care system. The intentions behind this position paper are to rise awareness of this special set of problems, to intensify cooperation between involved health care providers and to reduce incidence of diabetes mellitus as well as morbidity and mortality from diabetes in this patient group.

Effects of Glycogen Synthase Kinase-3 Beta Gene Polymorphisms on the Plasma Concentration of Aripiprazole in Chinese Patients with Schizophrenia: A Preliminary Study

This study explored the differences in glycogen synthase kinase-3 beta (GSK3β) gene polymorphisms between patients with schizophrenia and healthy controls and investigated the association between gene polymorphisms and plasma concentration of aripiprazole. We enrolled 127 patients with schizophrenia and 125 healthy controls from southern Fujian. The genotypes of the rs6438552, rs12630592, and rs3732361 loci of GSK3β were evaluated by sequencing with amplified polymerase chain reaction, and the plasma concentration of aripiprazole was determined by high-performance liquid chromatography-tandem mass spectrometry. All three loci of GSK3β had three genotypes each. The genotype distribution in each locus was not significantly different, but there was a significant difference in the allele frequency between the schizophrenia and control groups within each locus. Linkage disequilibrium analyses of the three single-nucleotide polymorphisms (SNPs) revealed strong linkage. The haplotype analysis results showed two haplotypes in the three SNPs of GSK3β. The plasma concentrations, dose-corrected concentrations, and normalized concentrations of aripiprazole were significantly different among the different genotypes of the three SNPs. In conclusion, the rs6438552, rs12630592, and rs3732361 loci of GSK3β may be involved in schizophrenia, and GSK3β gene polymorphism may be correlated with the plasma concentration of aripiprazole.

Mortality in Schizophrenia-Spectrum Disorders: Recent Advances in Understanding and Management

Schizophrenia is a life-shortening disease and life expectancy in patients may be 15-20 years shorter than in the general population, with increasing longevity gap over time. Premature mortality in schizophrenia-spectrum disorders is mainly due to preventable natural causes, such as cardio-vascular disease, infections, respiratory tract diseases and cancer, alongside suicide, homicide and accidents. There is a complex interplay of factors that act synergistically and cause physical morbidity to patients and subsequent mortality. Smoking, alcohol/substance abuse and sedentary life style, alongside disease-related factors, such as metabolic abnormalities and accelerating aging contribute to physical morbidity. Moreover, the symptomatology of psychosis and stigma may limit patients' access to quality medical care. Interventions to promote physical health in those patients should be multifaceted, and should target all patient-related modifiable factors, but also should address service-related healthcare disparities. Long-term antipsychotic use (including clozapine and long-acting injectables) is associated with substantially decreased all-cause mortality, including suicide and cardiovascular mortality, in patients with schizophrenia despite the well-known cardiometabolic adverse effects of second-generation agents. Integrated care may involve co-location of physical and mental health services, liaison services, shared protocols and information sharing systems, and has emerged as a way to address the physical health needs of those patients. Interventions to address mortality in schizophrenia and related syndromes should take place as early as possible in the course of the patients' treatment, and could be an integral component of care delivered by specialized early intervention services.

Evidence that the pituitary gland connects type 2 diabetes mellitus and schizophrenia based on large-scale trans-ethnic genetic analyses

BACKGROUND

Previous studies on European (EUR) samples have obtained inconsistent results regarding the genetic correlation between type 2 diabetes mellitus (T2DM) and Schizophrenia (SCZ). A large-scale trans-ethnic genetic analysis may provide additional evidence with enhanced power.

OBJECTIVE

We aimed to explore the genetic basis for both T2DM and SCZ based on large-scale genetic analyses of genome-wide association study (GWAS) data from both East Asian (EAS) and EUR subjects.

METHODS

A range of complementary approaches were employed to cross-validate the genetic correlation between T2DM and SCZ at the whole genome, autosomes (linkage disequilibrium score regression, LDSC), loci (Heritability Estimation from Summary Statistics, HESS), and causal variants (MiXeR and Mendelian randomization, MR) levels. Then, genome-wide and transcriptome-wide cross-trait/ethnic meta-analyses were performed separately to explore the effective shared organs, cells and molecular pathways.

RESULTS

A weak genome-wide negative genetic correlation between SCZ and T2DM was found for the EUR (r_g = - 0.098, P = 0.009) and EAS (r_g =- 0.053 and P = 0.032) populations, which showed no significant difference between the EUR and EAS populations (P = 0.22). After Bonferroni correction, the r_g remained significant only in the EUR population. Similar results were obtained from analyses at the levels of autosomes, loci and causal variants. 25 independent variants were firstly identified as being responsible for both SCZ and T2DM. The variants associated with the two disorders were significantly correlated to the gene expression profiles in the brain (P = 1.1E-9) and pituitary gland (P = 1.9E-6). Then, 61 protein-coding and non-coding genes were identified as effective genes in the pituitary gland (P < 9.23E-6) and were enriched in metabolic pathways related to glutathione mediated arsenate detoxification and to D-myo-inositol-trisphosphate.

CONCLUSION

Here, we show that a negative genetic correlation exists between SCZ and T2DM at the whole genome, autosome, locus and causal variant levels. We identify pituitary gland as a common effective organ for both diseases, in which non-protein-coding effective genes, such as lncRNAs, may be responsible for the negative genetic correlation. This highlights the importance of molecular metabolism and neuroendocrine modulation in the pituitary gland, which may be responsible for the initiation of T2DM in SCZ patients.

Implication of Melanocortin Receptor Genes in the Familial Comorbidity of Type 2 Diabetes and Depression

The melanocortin receptors are G-protein-coupled receptors, which are essential components of the hypothalamic–pituitary–adrenal axis, and they mediate the actions of melanocortins (melanocyte-stimulating hormones: α-MSH, β-MSH, and γ-MSH) as well as the adrenocorticotropin hormone (ACTH) in skin pigmentation, adrenal steroidogenesis, and stress response. Three melanocortin receptor genes (MC1R, MC2R, and MC5R) contribute to the risk of major depressive disorder (MDD), and one melanocortin receptor gene (MC4R) contributes to the risk of type 2 diabetes (T2D). MDD increases T2D risk in drug-naïve patients; thus, MDD and T2D commonly coexist. The five melanocortin receptor genes might confer risk for both disorders. However, they have never been investigated jointly to evaluate their potential contributing roles in the MDD-T2D comorbidity, specifically within families. In 212 Italian families with T2D and MDD, we tested 11 single nucleotide polymorphisms (SNPs) in the MC1R gene, 9 SNPs in MC2R, 3 SNPs in MC3R, 4 SNPs in MC4R, and 2 SNPs in MC5R. The testing used 2-point parametric linkage and linkage disequilibrium (LD) (i.e., association) analysis with four models (dominant with complete penetrance (D1), dominant with incomplete penetrance (D2), recessive with complete penetrance (R1), and recessive with incomplete penetrance (R2)). We detected significant (p ≤ 0.05) linkage and/or LD (i.e., association) to/with MDD for one SNP in MC2R (rs111734014) and one SNP in MC5R (rs2236700), and to/with T2D for three SNPs in MC1R (rs1805007 and rs201192930, and rs2228479), one SNP in MC2R (rs104894660), two SNPs in MC3R (rs3746619 and rs3827103), and one SNP in MC4R genes (Chr18-60372302). The linkage/LD/association was significant across different linkage patterns and different modes of inheritance. All reported variants are novel in MDD and T2D. This is the first study to report risk variants in MC1R, MC2R, and MC3R genes in T2D. MC2R and MC5R genes are replicated in MDD, with one novel variant each. Within our dataset, only the MC2R gene appears to confer risk for both MDD and T2D, albeit with different risk variants. To further clarity the role of the melanocortin receptor genes in MDD-T2D, these findings should be sought among other ethnicities as well.

Crosstalk between Schizophrenia and Metabolic Syndrome: The Role of Oxytocinergic Dysfunction

The high prevalence of metabolic syndrome in persons with schizophrenia has spurred investigational efforts to study the mechanism beneath its pathophysiology. Early psychosis dysfunction is present across multiple organ systems. On this account, schizophrenia may be a multisystem disorder in which one organ system is predominantly affected and where other organ systems are also concurrently involved. Growing evidence of the overlapping neurobiological profiles of metabolic risk factors and psychiatric symptoms, such as an association with cognitive dysfunction, altered autonomic nervous system regulation, desynchrony in the resting-state default mode network, and shared genetic liability, suggest that metabolic syndrome and schizophrenia are connected via common pathways that are central to schizophrenia pathogenesis, which may be underpinned by oxytocin system dysfunction. Oxytocin, a hormone that involves in the mechanisms of food intake and metabolic homeostasis, may partly explain this piece of the puzzle in the mechanism underlying this association. Given its prosocial and anorexigenic properties, oxytocin has been administered intranasally to investigate its therapeutic potential in schizophrenia and obesity. Although the pathophysiology and mechanisms of oxytocinergic dysfunction in metabolic syndrome and schizophrenia are both complex and it is still too early to draw a conclusion upon, oxytocinergic dysfunction may yield a new mechanistic insight into schizophrenia pathogenesis and treatment.

Influencing factors of obesity in community patients with deficit schizophrenia: a cross-sectional study

Background

Obesity is very common in patients with schizophrenia. We aimed to evaluate the influencing factors of obesity in community patients with deficit schizophrenia, to provide implication for schizophrenia management in community.

Methods

We selected patients with deficit schizophrenia who lived in 10 communities in our city from March 1 to June 30, 2021. The characteristics of included schizophrenia patients were evaluated and analyzed. Pearson correlation analysis was conducted to evaluate the obesity and related characteristics. Logistic regression analyses were conducted to assess the risk factors of obesity in patients with schizophrenia.

Results

A total of 284 patients with schizophrenia were included, the incidence of obesity in patients with schizophrenia was 56.70%. gender (r = 0.619), waist circumference (r = 0.644), BMI (r = 0.891), diabetes (r = 0.698), FG (r = 0.582), triglyceride (r = 0.618), HDL-C (r = −0.644), LDL-C (r = 0.583), apolipoprotein B (r = 0.595), and PANSS score (r = 0.813) were all correlated with the obesity in patients with schizophrenia (all p < 0.05). Logistic regression analysis indicated that female (OR 2.129, 95% CI 1.615–3.022), waist circumference ≥ 90 cm (OR 3.814, 95% CI 2.778 ~ 4.312), diabetes (OR 2.856, 95% CI 1.905 ~ 3.448), FG ≥ 88 mg/dL (OR 1.551, 95% CI 1.284 ~ 2.183), triglyceride ≥ 160 mg/dL (OR 1.804, 95% CI 1.236–2.845), HDL-C ≤ 0.8 mmol/L (OR 2.032, 95% CI 1.614–3.079), LDL-C ≥ 2.0 mmol/L (OR 1.926, 95% CI 1.442–2.041) and apolipoprotein B ≥ 0.70 g/L (OR 2.119, 95% CI 1.658–2.873) were the risk factors of obesity in patients with schizophrenia (all p < 0.05).

Conclusions

The obesity rate of patients with deficit schizophrenia in the community is high, and there are many associated risk factors. Early intervention targeted on those risk factors are warranted to reduce the obesity in schizophrenia patients.

Associations of Genetic Variants of Methylenetetrahydrofolate Reductase and Serum Folate Levels with Metabolic Parameters in Patients with Schizophrenia

The one-carbon metabolism pathway is a suitable candidate for studying the genetic and epigenetic factors contributing to metabolic abnormalities in patients with schizophrenia. We recruited 232 patients with schizophrenia and analyzed their serum folate, vitamin B12, and homocysteine levels and metabolic parameters to investigate the associations of genetic variants of methylenetetrahydrofolate reductase (MTHFR) and folate levels with metabolic parameters. MTHFR C677T and MTHFR A1298C were genotyped. Results showed that MTHFR 677T allele carriers had lower levels of total cholesterol and low-density lipoprotein cholesterol than those with the 677CC genotype. Metabolic parameters did not differ between MTHFR 1298C and 1298AA carriers. Patients with a low folate level had a lower high-density lipoprotein cholesterol level than those with a normal folate level, but the effect disappeared after adjustment for age, sex, and types of antipsychotics used. We found significant interactions between MTHFR A1298C and the folate level status (low vs. normal) in terms of body mass index and waist circumference. In conclusion, genetic variants in one-carbon metabolism might play a role in antipsychotic-induced metabolic abnormalities. Prospective studies on drug-naïve, first-episode patients with schizophrenia are warranted to identify key regions of DNA methylation changes accounting for antipsychotic-induced metabolic abnormalities.

Repurposing of Anti-Diabetic Agents as a New Opportunity to Alleviate Cognitive Impairment in Neurodegenerative and Neuropsychiatric Disorders

Cognitive impairment is a shared abnormality between type 2 diabetes mellitus (T2DM) and many neurodegenerative and neuropsychiatric disorders, such as Alzheimer’s disease (AD) and schizophrenia. Emerging evidence suggests that brain insulin resistance plays a significant role in cognitive deficits, which provides the possibility of anti-diabetic agents repositioning to alleviate cognitive deficits. Both preclinical and clinical studies have evaluated the potential cognitive enhancement effects of anti-diabetic agents targeting the insulin pathway. Repurposing of anti-diabetic agents is considered to be promising for cognitive deficits prevention or control in these neurodegenerative and neuropsychiatric disorders. This article reviewed the possible relationship between brain insulin resistance and cognitive deficits. In addition, promising therapeutic interventions, especially current advances in anti-diabetic agents targeting the insulin pathway to alleviate cognitive impairment in AD and schizophrenia were also summarized.