Parental history of type 2 diabetes in patients with nonaffective psychosis

Meta-analysis of a family history of diabetes in schizophrenia

OBJECTIVE

Type 2 diabetes (T2DM) is common in patients with schizophrenia and non-affective psychosis. These patients also have an increased prevalence of a family history of T2DM. We performed a systematic review and meta-analysis of the association between a family history of T2DM and schizophrenia.

METHOD

We searched electronic databases from inception until July 2022 for studies of a family history of T2DM or gestational diabetes in patients with schizophrenia and controls. We performed random effects meta-analysis, calculating odds ratios (ORs) and 95 % confidence intervals (CI) and meta-regression analyses.

RESULTS

Nine studies were included, comprising 2953 patients with non-affective psychosis and 4484 controls. Schizophrenia was associated with an over two-fold increased odds of a family history of T2DM or gestational diabetes (OR = 2.18, 95 % CI 1.61-2.96, p < 0.01). In meta-regression analyses, age, sex, study quality score, and year of publication were all unrelated to the association.

CONCLUSION

We found that patients with schizophrenia had a 2.2-fold increased odds of a family history of T2DM versus controls. This association may be relevant to both the pathophysiology of schizophrenia and the reported increased risk of development of diabetes with antipsychotic treatment.

Insulin Resistance/Diabetes and Schizophrenia: Potential Shared Genetic Factors and Implications for Better Management of Patients with Schizophrenia

Schizophrenia is a complex psychotic disorder with co-occurring conditions, including insulin resistance and type 2 diabetes (T2D). It is well established that T2D and its precursors (i.e., insulin resistance) are more prevalent in patients with schizophrenia who are treated with antipsychotics, as well as in antipsychotic-naïve patients experiencing their first episode of psychosis, compared with the general population. However, the mechanism(s) underlying the increased susceptibility, shared genetics, and possible cause-effect relationship between schizophrenia and T2D remain largely unknown. The objective of this narrative review was to synthesize important studies, including Mendelian randomization (MR) analyses that have integrated genome-wide association studies (GWAS), as well as results from in vitro models, in vivo models, and observational studies of patients with schizophrenia. Both GWAS and MR studies have found that schizophrenia and T2D/insulin resistance share genetic risk factors, and this may mediate a connection between peripheral or brain insulin resistance and T2D with cognition impairment and an increased risk of developing prediabetes and T2D in schizophrenia. Moreover, accumulating evidence supports a causal role for insulin resistance in schizophrenia and emphasizes the importance of a genetic basis for susceptibility to T2D in patients with schizophrenia before they receive psychotic treatment. The present findings and observations may have clinical implications for the development of better strategies to treat patients with schizophrenia, with both pharmacological (i.e., samidorphan, empagliflozin) and/or nonpharmacological (i.e., lifestyle changes) approaches. Additionally, this review may benefit the design of future studies by physicians and clinical investigators.

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.

Familial aggregation and shared genetic loading for major psychiatric disorders and type 2 diabetes

AIMS/HYPOTHESIS

Psychiatric disorders, such as schizophrenia (SCZ), major depressive disorder (MDD) and bipolar disorder (BPD), are highly comorbid with type 2 diabetes. However, the mechanisms underlying such comorbidity are understudied. This study explored the familial aggregation of common psychiatric disorders and type 2 diabetes by testing family history association, and investigated the shared genetic loading between them by testing the polygenic risk score (PRS) association.

METHODS

A total of 105,184 participants were recruited from the Taiwan Biobank, and genome-wide genotyping data were available for 95,238 participants. The Psychiatric Genomics Consortium-derived PRS for SCZ, MDD and BPD was calculated. Logistic regression was used to estimate the OR with CIs between a family history of SCZ/MDD/BPD and a family history of type 2 diabetes, and between the PRS and the risk of type 2 diabetes.

RESULTS

A family history of type 2 diabetes was associated with a family history of SCZ (OR 1.23, 95% CI 1.08, 1.40), MDD (OR 1.19, 95% CI 1.13, 1.26) and BPD (OR 1.26, 95% CI 1.15, 1.39). Compared with paternal type 2 diabetes, maternal type 2 diabetes was associated with a higher risk of a family history of SCZ. SCZ PRS was negatively associated with type 2 diabetes in women (OR 0.92, 95% CI 0.88, 0.97), but not in men; the effect of SCZ PRS reduced after adjusting for BMI. MDD PRS was positively associated with type 2 diabetes (OR 1.04, 95% CI 1.00, 1.07); the effect of MDD PRS reduced after adjusting for BMI or smoking. BPD PRS was not associated with type 2 diabetes.

CONCLUSIONS/INTERPRETATION

The comorbidity of type 2 diabetes with psychiatric disorders may be explained by shared familial factors. The shared polygenic loading between MDD and type 2 diabetes implies not only pleiotropy but also a shared genetic aetiology for the mechanism behind the comorbidity. The negative correlation between polygenic loading for SCZ and type 2 diabetes implies the role of environmental factors.

Brexpiprazole caused glycolipid metabolic disorder by inhibiting GLP1/GLP1R signaling in rats

Brexpiprazole (Bre) is a new multi-target antipsychotic drug (APD) approved by the US FDA in 2015, and shows good therapeutic potential. But it lacks assessments on the metabolic side effects, which obstructs the treatment of schizophrenia. Glucagon-like peptide 1 (GLP1), an incretin associated with insulin action and metabolism, is involved in the metabolic syndrome (MS) caused by most APDs. In this study, we examined the adverse effects of Bre on glycolipid metabolism in rats and determined whether GLP1 was involved in Bre-caused MS. In the first part of experiments, rats were orally administered Bre (0.5 mg· kg^-1· d^-1) for 28 days with aripiprazole (1.0 mg· kg^-1· d^-1) or olanzapine (1.0 mg· kg^-1· d^-1) as the controls. Compared to vehicle, Bre administration significantly increased the weight gain, serum lipid (TG, TC, LDL, FFA), and blood glucose levels accompanied by the hormonal (insulin, glucagon, GLP1) imbalance, and the impaired glucose tolerance and insulin sensitivity. Moreover, we demonstrated that Bre administration significantly decreased the protein and mRNA levels of GLP1 in pancreas and small intestine by suppressing CaMKIIα, AMPK, and β-catenin; Bre administration also caused islet dysfunction with decreased GLP1R, PI3K, IRβ expression in pancreas, and the interference of IRS1, PI3K, p-AKT, and GLUT4 expression in the liver and skeletal muscle that represented the insulin resistance. In the second part of experiments, rats were orally administered Bre (0.5 mg· kg^-1· d^-1) for 42 days. We showed that co-administration with the GLP1 receptor (GLP1R) agonist liraglutide (0.125 mg· kg^-1· d^-1, ip) could ameliorate Bre-caused metabolic abnormalities. Our results demonstrate that GLP1/GLP1R signaling is involved in Bre-induced glycolipid metabolic disorders and co-treatment with liraglutide is an effective intervention against those abnormal metabolisms.

Glucose homeostasis in unaffected first-degree relatives of schizophrenia patients: A systematic review and meta-analysis

It has been proposed that type 2 diabetes and schizophrenia-spectrum disorders share overlapping genetic backgrounds. Therefore, we aimed to perform a systematic review and meta-analysis of studies comparing fasting levels of glucose and insulin, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), glucose levels during the oral glucose tolerance test (OGTT) and the levels of glycated hemoglobin (HbA1c) in unaffected first-degree relatives of patients with schizophrenia and controls. Online searches covered the publication period from database inception until May 8th 2020. Meta-analyses were performed using random-effects models with Hedges' g as the effect size estimate. Out of 2556 records identified, 12 studies representing 672 relatives of schizophrenia patients and 6446 controls were found to be eligible. There were no significant differences in fasting levels of glucose (g = 0.54, 95%CI = -0.26 to 1.35, p = 0.188) and insulin (g = 0.07, 95%CI = -0.14 to 0.29, p = 0.491), HOMA-IR (g = 0.12, 95%CI = -0.19 to 0.43, p = 0.433), and the levels of HbA1c (g = 0.38, 95%CI = -0.02 to 0.77, p = 0.061) between relatives of schizophrenia patients and controls. Two studies demonstrated significantly higher 2-hour glucose levels during OGTT in relatives of patients with schizophrenia (g = 0.90, 95%CI = 0.49 to 1.31, p < 0.001). Our findings do not support the hypothesis that familial liability to psychosis is related to altered fasting parameters of glucose homeostasis. However, this population might show impaired glucose tolerance. More studies are needed to confirm these observations.

The Relative Risk of Developing Type 2 Diabetes Mellitus in Young Adults with Schizophrenia Treated with Different Atypical Antipsychotic

Background and aim: While the link between antipsychotic treatment and metabolic adverse events, including type 2 diabetes mellitus (T2DM) are clear in adults with schizophrenia, in young this association is not so well studied although the use of secondgeneration antipsychotics (SGA) is more and more frequent.

Material and methods: The local diabetes register was compared with the list of all registered young adults (18-35 years) with schizophrenia 2 years retrospective and 2 years prospective. Cumulative incidence, rate of incidence and relative risk was calculated knowing the number of persons in this age group within this region.

Results: Cumulative incidence for exposed group was 0.7% with a rate of incidence of 6.27 (95%CI: 4.1-10.5) per 1,000 patientyears, when in normal population was 0.2%, respectively 2.01 (95%CI: 0.72-3.79). This means a relative risk of 3.4736 (95%CI: 1.79-6.72), p=0.0002 and NNH=202 (95%CI: 134-404). Multivariate analysis showed that gender male (OR=1.83; 95%CI: 0.9-2.7; p=0.002) and olanzapine prescription (OR=4.76; 95%CI: 1.7-7.7; p=0.0001) were independent risk factors for T2DM.

Conclusions: The metabolic risk should be taken in account every time introducing or changing a SGA in young schizophrenic patient, balancing the benefits and negative metabolic effects (especially with olanzapine). Healthy nutrition and physical activities are necessary components of these patients lifestyle to avoid early onset of T2DM.

Meta-analysis of comorbid diabetes and family history of diabetes in non-affective psychosis

OBJECTIVE

Schizophrenia and other non-affective psychoses (NAP) are associated with an increased prevalence of both type 2 diabetes (DM2) as well as a family history of DM2. We performed a systematic review and meta-analysis of the association between comorbid DM2 and a family history of DM2 in patients with NAP.

METHOD

We searched major electronic databases from inception until August 2018 for studies of comorbid DM2 in patients with non-affective psychosis and family history of DM2 status. Random effects meta-analysis calculating odds ratios (ORs) and 95% confidence intervals (CI) and meta-regression analyses were performed.

RESULTS

Ten studies met the inclusion criteria. Across these studies, there were 804 patients with non-affective psychosis and comorbid DM2, and 2976 patients with non-affective psychosis without this comorbidity. A family history of DM2 was associated with an over four-fold increased odds of comorbid DM2 in patients with NAP (OR = 4.3, 95% CI 2.9-6.4, p<0.001). In; meta-regression analyses older age, but not sex, BMI, geographic region, study quality, or year; of publication moderated the association between comorbid DM2 and family history of DM2.

CONCLUSION

We found that a family history of DM2 was associated with an over four-fold increased odds of comorbid DM2 in patients with NAP. This association may be due to shared environmental or genetic risk factors, or gene-environment interactions. Given the increased risk of incident diabetes with antipsychotic treatment, screening for a family history of DM2 is germane to the clinical care of patients with NAP.

Glycated Haemoglobin Is Associated With Poorer Cognitive Performance in Patients With Recent-Onset Psychosis

BACKGROUND

Glucose abnormalities and cognitive alterations are present before the onset of schizophrenia. We aimed to study whether glucose metabolism parameters are associated with cognitive functioning in recent-onset psychosis (ROP) patients while adjusting for hypothalamic-pituitary adrenal (HPA) axis measures.

METHODS

Sixty ROP outpatients and 50 healthy subjects (HS) were studied. Cognitive function was assessed with the MATRICS Consensus Cognitive Battery. Glycated haemoglobin (HbA1_c), glucose, insulin, and C-peptide levels were determined in plasma. The HOMA-insulin resistance index was calculated. Salivary samples were obtained at home on another day to assess the cortisol awakening response and cortisol levels during the day. Univariate analyses were conducted to explore the association between glucose metabolism parameters and cognitive tasks. For those parameters that were more clearly associated with the cognitive outcome, multiple linear regression analyses were conducted to adjust for covariates. Each cognitive task was considered the dependent variable. Covariates were age, sex, education level, diagnosis, antipsychotic and benzodiazepine treatment, body mass index (BMI), smoking, and HPA axis measures. Potential interactions between diagnosis and glucose parameters were tested.

RESULTS

There were no significant differences in HPA axis measures or glucose parameters, with the exception of C-peptide (that was higher in ROP patients), between groups. ROP patients had a lower performance than HS in all cognitive tasks (p < 0.01 for all tasks). Of all glucose metabolism parameters, HbA1c levels were more clearly associated with cognitive impairment in cognitive tasks dealing with executive functions and visual memory in both ROP patients and HS. Multivariate analyses found a significant negative association between HbA1c and cognitive functioning in five cognitive tasks dealing with executive functions, visual memory and attention/vigilance (a ROP diagnosis by HbA1_c negative interaction was found in this latter cognitive domain, suggesting that HBA1_c levels are associated with impaired attention only in ROP patients).

CONCLUSIONS

Our study found that HbA1_c was negatively associated with cognitive functioning in both ROP patients and HS in tasks dealing with executive functions and visual memory. In ROP patients, HbA1_c was also associated with impaired attention. These results were independent of BMI and measures of HPA axis activity.

Birth weight, family history of diabetes and diabetes onset in schizophrenia

INTRODUCTION

The prevalence of diabetes in schizophrenia is twice that in the general population, but there are few reliable predictors of which individuals will develop glucose dysregulation.

OBJECTIVE

To test if abnormal birth weight (either too low or too high) and parental diabetes, both variables that can be ascertained in the clinic, can predict diabetes onset in patients with schizophrenia.

RESEARCH DESIGN AND METHODS

Electronic records of a cohort of 190 clozapine-treated patients (37% treated for more than 20 years) and Cox regression survival analysis (with any type of glucose dysregulation as the event) to account for differences in length of treatment before the event and age at clozapine treatment initiation.

RESULTS

Age at clozapine initiation (Exp(B)=1.098; p<0.001), family history of diabetes (Exp(B)=2.299; p=0.049) and birth weight² (Exp(B)=0.999; p=0.013) were significant predictors of glucose dysregulation onset, while gender was not (Exp(B)=0.1.350; p=0.517). Among individuals with 10 years of follow-up, 80% of those with both abnormal birth weight and a family history of diabetes developed diabetes compared with 56% with only abnormal birth weight, 40% with only a family history of diabetes and 20% in those with neither.

CONCLUSIONS

Since 48% of cases had at least one risk factor and 6% had both risk factors, there is a substantial proportion of patients for whom preventive strategies could be implemented.

Increased risk of type 2 diabetes among the siblings of patients with schizophrenia

BACKGROUND

Research suggests an association between metabolic disorders, such as type 2 diabetes mellitus (T2DM), and schizophrenia. However, the risk of metabolic disorders in the unaffected siblings of patients with schizophrenia remains unclear.

METHODS

Using the Taiwan National Health Insurance Research Database, 3135 unaffected siblings of schizophrenia probands and 12,540 age-/sex-matched control subjects were included and followed up to the end of 2011. Individuals who developed metabolic disorders during the follow-up period were identified.

RESULTS

The unaffected siblings of schizophrenia probands had a higher prevalence of T2DM (3.4% vs. 2.6%, p = 0.010) than the controls. Logistic regression analyses with the adjustment of demographic data revealed that the unaffected siblings of patients with schizophrenia were more likely to develop T2DM (odds ratio [OR]: 1.39, 95% confidence interval [CI]: 1.10-1.75) later in life compared with the control group. Moreover, only female siblings of schizophrenia probands had an increased risk of hypertension (OR: 1.47, 95% CI: 1.07-2.01) during the follow-up compared with the controls.DiscussionThe unaffected siblings, especially sisters, of schizophrenia probands had a higher prevalence of T2DM and hypertension compared with the controls. Our study revealed a familial link between schizophrenia and T2DM in a large sample. Additional studies are required to investigate the shared pathophysiology of schizophrenia and T2DM.

Parental hospital-treated somatic illnesses and psychosis of the offspring-The Northern Finland Birth Cohort 1986 study

AIM

The aim of this study was to investigate whether parental somatic illnesses during childhood increase the risk for later psychosis in the offspring. In addition, we examined which parental illnesses in particular are associated with increased risk of psychosis in the offspring.

METHOD

The data of the Northern Finland Birth Cohort 1986 (NFBC 1986), included 9137 children born alive in northern Finland between the July 1, 1985, and the June 30, 1986. Information regarding the parents' somatic morbidity was collected through various healthcare registers up to age 28 of the cohort members.

RESULTS

Psychosis was diagnosed in 169 (1.8%) of the cohort members between the ages of 16 and 28. Accumulation of parental somatic diseases was related to later psychosis in the offspring. In addition, some specific somatic diagnostic groups of parents were emphasized in relation to psychosis in the offspring.

CONCLUSIONS

Our study findings indicated that parental somatic illness should be taken into account in the prevention of serious mental health problems in their offspring.

Co-shared genetics and possible risk gene pathway partially explain the comorbidity of schizophrenia, major depressive disorder, type 2 diabetes, and metabolic syndrome

Schizophrenia (SCZ) and major depressive disorder (MDD) in treatment-naive patients are associated with increased risk for type 2 diabetes (T2D) and metabolic syndrome (MetS). SCZ, MDD, T2D, and MetS are often comorbid and their comorbidity increases cardiovascular risk: Some risk genes are likely co-shared by them. For instance, transcription factor 7-like 2 (TCF7L2) and proteasome 26S subunit, non-ATPase 9 (PSMD9) are two genes independently reported as contributing to T2D and SCZ, and PSMD9 to MDD as well. However, there are scarce data on the shared genetic risk among SCZ, MDD, T2D, and/or MetS. Here, we briefly describe T2D, MetS, SCZ, and MDD and their genetic architecture. Next, we report separately about the comorbidity of SCZ and MDD with T2D and MetS, and their respective genetic overlap. We propose a novel hypothesis that genes of the prolactin (PRL)-pathway may be implicated in the comorbidity of these disorders. The inherited predisposition of patients with SCZ and MDD to psychoneuroendocrine dysfunction may confer increased risk of T2D and MetS. We illustrate a strategy to identify risk variants in each disorder and in their comorbid psychoneuroendocrine and mental-metabolic dysfunctions, advocating for studies of genetically homogeneous and phenotype-rich families. The results will guide future studies of the shared predisposition and molecular genetics of new homogeneous endophenotypes of SCZ, MDD, and metabolic impairment.

Antipsychotics and glucose metabolism: how brain and body collide

Since the serendipitous discovery of the first antipsychotic (AP) drug in the 1950s, APs remain the cornerstone of treatment for schizophrenia. A shift over the past two decades away from first-generation, conventional APs to so-called "atypical" (or 2nd/3rd generation) APs parallels acknowledgment of serious metabolic side-effects associated in particular with these newer agents. As will be reviewed, AP drugs and type 2 diabetes are now inextricably linked, contributing to the three- to fivefold increased risk of type 2 diabetes observed in schizophrenia. However, this association is not straightforward. Biological and lifestyle-related illness factors contribute to the association between type 2 diabetes and metabolic disease independently of AP treatment. In addition, APs have a well-established weight gain propensity which could also account for elevated risk of insulin resistance and type 2 diabetes. However, compelling preclinical and clinical evidence now suggests that these drugs can rapidly and directly influence pathways of glucose metabolism independently of weight gain and even in absence of psychiatric illness. Mechanisms of these direct effects remain poorly elucidated but may involve central and peripheral antagonism of neurotransmitters implicated not only in the therapeutic effects of APs but also in glucose homeostasis, possibly via effects on the autonomic nervous system. The clinical relevance of studying "direct" effects of these drugs on glucose metabolism is underscored by the widespread use of these medications, both on and off label, for a growing number of mental illnesses, extending safety concerns well beyond schizophrenia.

Association between parental hospital-treated somatic illnesses in childhood and later mental disorders among offspring up to early adulthood: An explorative study in the 1987 Finnish Birth Cohort

Aims: Earlier studies on the associations between parental somatic illnesses and children’s psychological wellbeing have focused on the most common somatic illnesses or on specific groups of illnesses. In this study, we aimed to systematically examine whether parental somatic illnesses, diagnosed during an offspring’s childhood, are associated with later mental disorders of the offspring and, if so, identify which parental somatic illnesses in particular increase the likelihood for later mental disorders among the offspring. Methods: The 1987 Finnish Birth Cohort study yields longitudinal nationwide follow-up data that include a complete census of children born in a single year. Children have been followed over time through to the year 2012 using official registers maintained by the Finnish authorities. Parental diagnoses of specialised hospital inpatient care were identified from the Hospital Discharge Register after children’s birth and followed up until the end of 1995. Children’s psychiatric diagnoses from specialised hospital care were identified from the same register for the periods 1996/1998–2012. Logistic regression analyses were used to calculate sex-specific odds ratios for associations of mental disorders with maternal and paternal somatic illnesses using parental death, education, social assistance and psychiatric inpatient care as covariates. Results: Parental somatic illnesses during an offspring’s childhood seem to increase the risk for later mental disorders. Several previously unreported somatic parental illnesses were found to be significantly associated with offspring’s later mental health. Conclusions: Parental somatic illnesses should be considered as a significant adverse childhood life event, calling for preventive actions and child-centred support in adult healthcare.

Higher schizotypy predicts better metabolic profile in unaffected siblings of patients with schizophrenia

RATIONALE

Type 2 diabetes (T2D) is more frequent in schizophrenia (Sz) than in the general population. This association is partly accounted for by shared susceptibility genetic variants.

OBJECTIVE

We tested the hypotheses that a genetic predisposition to Sz would be associated with higher likelihood of insulin resistance (IR), and that IR would be predicted by subthreshold psychosis phenotypes.

METHODS

Unaffected siblings of Sz patients (n = 101) were compared with a nonclinical sample (n = 305) in terms of IR, schizotypy (SzTy), and a behavioural experiment of "jumping to conclusions". The measures, respectively, were the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Structured Interview for Schizotypy-Revised (SIS-R), and the Beads Task (BT). The likelihood of IR was examined in multiple regression models that included sociodemographic, metabolic, and cognitive parameters alongside group status, SIS-R scores, and BT performance.

RESULTS

Insulin resistance was less frequent in siblings (31.7%) compared to controls (43.3%) (p < 0.05), and negatively associated with SzTy, as compared among the tertile groups for the latter (p < 0.001). The regression model that examined all relevant parameters included the tSzTy tertiles, TG and HDL-C levels, and BMI, as significant predictors of IR. Lack of IR was predicted by the highest as compared to the lowest SzTy tertile [OR (95%CI): 0.43 (0.21-0.85), p = 0.015].

CONCLUSION

Higher dopaminergic activity may contribute to both schizotypal features and a favourable metabolic profile in the same individual. This is compatible with dopamine's regulatory role in glucose metabolism via indirect central actions and a direct action on pancreatic insulin secretion. The relationship between dopaminergic activity and metabolic profile in Sz must be examined in longitudinal studies with younger unaffected siblings.

Comorbidity of chronic somatic diseases in patients with psychotic disorders and their influence on 4-year outcomes of integrated care treatment (ACCESS II study)

BACKGROUND

People with psychotic disorders fulfilling criteria of a severe and persistent mental illness (SPMI) display a high risk of somatic comorbidity (SC).

METHODS

ACCESS II is a prospective, long-term study examining the effectiveness of Integrated Care for people with psychotic disorders fulfilling SPMI criteria. Chronic comorbid somatic disorders were systematically assessed according to ICD-10-GM criteria. Patients treated for ≥4years in ACCESS were categorized as early psychosis (treatment: ≤2years) or non-early psychosis (treatment: >2years) patients.

RESULTS

Of 187 patients treated in ACCESS for ≥4years (mean age=41.8years, males=44.4%), 145 (77.5%) had SC, (mean=2.1±2.1). Overall, 55 different diseases from 15 different ICD-10-GM disease areas were identified. Prevalence of ≥1 SC (p=0.09) and specific types of SC (p=0.08-1.00) did not differ between early and non-early psychosis patients, but non-early psychosis patients had a higher mean number of SC (2.3±2.2 vs. 1.3±1.3, p=0.002). SC patients had higher rates of comorbid mental disorders (93% vs. 81%, p=0.002), specifically posttraumatic stress disorder (23% vs. 7%, p=0.002), and suicide attempts (43% vs. 19%, p<0.001). At the 4-year endpoint, both patients with and without comorbidity displayed major improvements in psychopathology, severity of illness, functioning, quality of life and satisfaction with care.

CONCLUSIONS

SC is frequent in patients with severe psychotic disorders, even in the early psychosis phase. The magnitude of the problem underlines the need for regular screening, comprehensive assessment, preventive pharmacotherapy, and targeted SC management.

Genetic variants of increased waist circumference in psychosis

We examined whether established metabolic risk genetic variants in the population confer a risk for increased waist circumference in patients with schizophrenia spectrum disorders and also an association with schizophrenia spectrum disorders irrespective of waist circumference.

Metabolic syndrome in psychiatry: advances in understanding and management

Metabolic syndrome comprises a number of cardiovascular risk factors that increase morbidity and mortality. The increase in incidence of the syndrome among psychiatric patients has been unanimously demonstrated in recent studies and it has become one of the greatest challenges in psychiatric practice. Besides the use of psychotropic drugs, factors such as genetic polymorphisms, inflammation, endocrinopathies and unhealthy lifestyle contribute to the association between metabolic syndrome and a number of psychiatric disorders. In this article, we review the current diagnostic criteria for metabolic syndrome and propose clinically useful guidelines for psychiatrists to identify and monitor patients who may have the syndrome. We also outline the relationship between metabolic syndrome and individual psychiatric disorders, and discuss advances in pharmacological treatment for the syndrome, such as metformin.

LEARNING OBJECTIVES

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Meta-analysis of glucose tolerance, insulin, and insulin resistance in antipsychotic-naïve patients with nonaffective psychosis

BACKGROUND

Some studies have suggested that antipsychotic-naïve patients with nonaffective psychosis (NAP) have glucose intolerance.

AIMS

To conduct a systematic review and meta-analysis of fasting glucose (FG), two hour values in the oral glucose tolerance test (2HG), fasting insulin concentration (INS), and insulin resistance (IR).

METHOD

We identified possibly relevant studies, then selected studies, following usual guidelines, with two authors reviewing the manuscripts. We required studies to include subjects with nonaffective psychosis and control subjects.

RESULTS

There were 911 patients and 870 control subjects in the analysis of FG; their average ages were respectively 28.7 and 29.5years. Significant differences were found for all four variables, with effect size estimates ranging from 0.21 to 0.58.

CONCLUSIONS

As a group, at the time of first clinical contact for psychosis, people with NAP have a slight increase in FG, which most of them maintain in the normal range despite a small increase in IR by secreting additional INS. When faced with a physiological challenge such as a glucose tolerance test or antipsychotics, they are no longer able to maintain a normal glucose concentration.

From Molecules to the Clinic: Linking Schizophrenia and Metabolic Syndrome through Sphingolipids Metabolism

Metabolic syndrome (MS) is a prevalent and severe comorbidity observed in schizophrenia (SZ). The exact nature of this association is controversial and very often accredited to the effects of psychotropic medications and disease-induced life-style modifications, such as inactive lifestyle, poor dietary choices, and smoking. However, drug therapy and disease-induced lifestyle factors are likely not the only factors contributing to the observed converging nature of these conditions, since an increased prevalence of MS is also observed in first episode and drug-naïve psychosis populations. MS and SZ share common intrinsic susceptibility factors and etiopathogenic mechanisms, which may change the way we approach clinical management of SZ patients. Among the most relevant common pathogenic pathways of SZ and MS are alterations in the sphingolipids (SLs) metabolism and SLs homeostasis. SLs have important structural functions as they participate in the formation of membrane “lipid rafts.” SLs also play physiological roles in cell differentiation, proliferation, and inflammatory processes, which might be part of MS/SZ common pathophysiological processes. In this article we review a plausible mechanism to explain the link between MS and SZ through a disruption in SL homeostasis. Additionally, we provide insights on how this hypothesis can lead to the developing of new diagnostic/therapeutic technologies for SZ patients.

Impaired glucose tolerance in first-episode drug-naïve patients with schizophrenia: relationships with clinical phenotypes and cognitive deficits

BACKGROUND

Schizophrenia patients have a higher prevalence of type 2 diabetes mellitus with impaired glucose tolerance (IGT) than normals. We examined the relationship between IGT and clinical phenotypes or cognitive deficits in first-episode, drug-naïve (FEDN) Han Chinese patients with schizophrenia.

METHOD

A total of 175 in-patients were compared with 31 healthy controls on anthropometric measures and fasting plasma levels of glucose, insulin and lipids. They were also compared using a 75 g oral glucose tolerance test and the homeostasis model assessment of insulin resistance (HOMA-IR). Neurocognitive functioning was assessed using the MATRICS Consensus Cognitive Battery (MCCB). Patient psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Of the patients, 24.5% had IGT compared with none of the controls, and they also had significantly higher levels of fasting blood glucose and 2-h glucose after an oral glucose load, and were more insulin resistant. Compared with those patients with normal glucose tolerance, the IGT patients were older, had a later age of onset, higher waist or hip circumference and body mass index, higher levels of low-density lipoprotein and triglycerides and higher insulin resistance. Furthermore, IGT patients had higher PANSS total and negative symptom subscale scores, but no greater cognitive impairment except on the emotional intelligence index of the MCCB.

CONCLUSIONS

IGT occurs with greater frequency in FEDN schizophrenia, and shows association with demographic and anthropometric parameters, as well as with clinical symptoms but minimally with cognitive impairment during the early course of the disorder.

Parental type 2 diabetes in patients with non-affective psychosis

OBJECTIVE

People with schizophrenia have an increased risk of diabetes that may be independent of antipsychotics. Previous studies have explored the prevalence of a family history of type 2 diabetes (DM2) in schizophrenia. We hypothesized that parental DM2 is increased in probands with non-affective psychosis (NAP) compared to controls, and parental DM2 predicts comorbid diabetes in NAP, after controlling for potential confounders.

METHOD

N=217 patients with NAP and N=67 controls were interviewed for a history of parental DM2. NAP was investigated as a predictor of parental DM2 in binary logistic regression models, controlling for age, sex, race, smoking, body mass index, socioeconomic status, and parental psychiatric history.

RESULTS

There was an increased prevalence of DM2 in the mother (30.0% vs 13.8%, p=0.013) and in either the mother or father (44.5% vs 24.6%, p=0.006) in patients with NAP versus controls. After accounting for potential confounders, NAP was associated with significant increased odds of parental DM2 (OR=2.80, 95% CI 1.08-7.23, p=0.034). Parental DM2 was also associated with increased odds of comorbid DM2 in NAP (OR=3.67, 95% CI 1.58-8.56, p=0.003).

CONCLUSIONS

We replicated an association of an increased prevalence of parental DM2 in patients with NAP. Parental DM2 was also an independent predictor of comorbid DM2 in these patients. These associations may be due to shared environmental or genetic risk factors, or gene by environment interactions. Given risks of incident diabetes with antipsychotic treatment, screening for parental DM2 status is germane to the clinical care of patients with NAP.

Polygenic risk for type 2 diabetes mellitus among individuals with psychosis and their relatives

BACKGROUND

An elevated prevalence of Type 2 diabetes (T2D) has been observed in people with psychotic disorders and their relatives compared to the general population. It is not known whether this population also has increased genetic risk for T2D.

METHODS

Subjects included probands with schizophrenia, schizoaffective disorder, or psychotic bipolar I disorder, their first-degree relatives without psychotic disorders, and healthy controls, who participated in the Bipolar Schizophrenia Network for Intermediate Phenotypes study. We constructed sets of polygenic risk scores for T2D (PGRST2D) and schizophrenia (PGRSSCHIZ) using publicly available data from genome-wide association studies. We then explored the correlation of PGRST2D with psychiatric proband or relative status, and with self-reported diabetes. Caucasians and African-Americans were analyzed separately. We also evaluated correlations between PGRSSCHIZ and diabetes mellitus among Caucasian probands and their relatives.

RESULTS

In Caucasians, PGRST2D was correlated with self-reported diabetes mellitus within probands, but was not correlated with proband or relative status in the whole sample. In African-Americans, a PGRST2D based on selected risk alleles for T2D in this population did not correlate with proband or relative status. PGRSSCHIZ was not correlated with self-reported diabetes within Caucasian probands.

CONCLUSION

Differences in polygenic risk for T2D do not explain the increased prevalence of diabetes mellitus observed in psychosis probands and their relatives.

Abnormal glycemic homeostasis at the onset of serious mental illnesses: A common pathway

OBJECTIVE

Patients with serious mental illnesses exhibit a reduced lifespan compared with the general population, a finding that can not solely rely on high suicide risk, low access to medical care and unhealthy lifestyle. The main causes of death are medical related pathologies such as type 2 diabetes mellitus and cardiovascular disease; however pharmacological treatment might play a role.

MATERIAL AND METHODS

We compared a two hour glucose load in naïve patients at the onset of a serious mental illness (N=102) (84 patients with a first episode of schizophrenia and related disorders, 6 with a first episode of bipolar I disorder and 12 with a first episode of major depression disorder) with another psychiatric diagnose, adjustment disorder (N=17) and matched controls (N=98).

RESULTS

Young patients with serious mental illness showed an increased two hour glucose load compared with adjustment disorder and the control group. Mean two hour glucose values [±standard deviation] were: for schizophrenia and related disorders 106.51mg/dL [±32.0], for bipolar disorder 118.33mg/dL [±34.3], for major depressive disorder 107.42mg/dL [±34.5], for adjustment disorder 79.06mg/dL[±24.4] and for the control group 82.11mg/dL [±23.3] (p<0.001).

CONCLUSIONS

Our results reflect an abnormal metabolic pathway at the onset of the disease before any pharmacological treatment or other confounding factors might have taken place. Our results suggest a similar glycemic pathway in serious mental illnesses and the subsequent need of primary and secondary prevention strategies.

Common familial risk factors for schizophrenia and diabetes mellitus

OBJECTIVE

The co-occurrence of type 2 diabetes and psychosis is an important form of medical comorbidity within individuals, but no large-scale study has evaluated comorbidity within families. The aim of this study was to determine whether there is evidence for familial comorbidity between type 2 diabetes and psychosis.

METHOD

Data were analysed from an observational study of a nationally representative sample of 1642 people with psychosis who were in contact with psychiatric services at the time of survey (The 2010 Australian National Survey of Psychosis). Participants were aged 18-64 years and met World Health Organization's International Classification of Diseases, 10th Revision diagnostic criteria for a psychotic disorder (857 with schizophrenia, 319 with bipolar disorder with psychotic features, 293 with schizoaffective disorder, 81 with depressive psychosis and 92 with delusional disorder or other non-organic psychoses). Logistic regression was used to estimate the association between a family history of diabetes and a family history of schizophrenia.

RESULTS

A positive family history of diabetes was associated with a positive family history of schizophrenia in those with a psychotic disorder (odds ratio = 1.35, p = 0.01, adjusted for age and gender). The association was different in those with an affective versus non-affective psychosis (odds ratio = 0.613, p = 0.019, adjusted for age and gender) and was significant only in those with a non-affective psychosis, specifically schizophrenia (odds ratio = 1.58, p = 0.005, adjusted for age and sex). Adjustment for demographic factors in those with schizophrenia slightly strengthened the association (odds ratio = 1.74, p = 0.001, adjusted for age, gender, diagnosis, ethnicity, education, employment, income and marital status).

CONCLUSION

Elevated risk for type 2 diabetes in people with schizophrenia is not simply a consequence of antipsychotic medication; type 2 diabetes and schizophrenia share familial risk factors.

Dopamine-prolactin pathway potentially contributes to the schizophrenia and type 2 diabetes comorbidity

Schizophrenia (SCZ) and type 2 diabetes (T2D) are clinically associated, and common knowledge attributes this association to side effects of antipsychotic treatment. However, even drug-naive patients with SCZ are at increased risk for T2D. Dopamine dysfunction has a central role in SCZ. It is well-known that dopamine constitutively inhibits prolactin (PRL) secretion via the dopamine receptor 2 (DR2D). If dopamine is increased or if dopamine receptors hyperfunction, PRL may be reduced. During the first SCZ episode, low PRL levels are associated with worse symptoms. PRL is essential in human and social bonding, as well as it is implicated in glucose homeostasis. Dopamine dysfunction, beyond contributing to SCZ symptoms, may lead to altered appetite and T2D. To our knowledge, there are no studies of the genetics of the SCZ-T2D comorbidity focusing jointly on the dopamine and PRL pathway in the attempt to capture molecular heterogeneity correlated to possible disease manifestation heterogeneity. In this dopamine-PRL pathway-focused-hypothesis-driven review on the association of SCZ with T2D, we report a specific revision of what it is known about PRL and dopamine in relation to what we theorize is one of the missing links between the two disorders. We suggest that new studies are necessary to establish the genetic role of PRL and dopamine pathway in SCZ-T2D comorbidity.

A systematic review of genetic variants associated with metabolic syndrome in patients with schizophrenia

Metabolic syndrome (MetS) is a cluster of factors that increases the risk of cardiovascular disease (CVD), one of the leading causes of mortality in patients with schizophrenia. Incidence rates of MetS are significantly higher in patients with schizophrenia compared to the general population. Several factors contribute to this high comorbidity. This systematic review focuses on genetic factors and interrogates data from association studies of genes implicated in the development of MetS in patients with schizophrenia. We aimed to identify variants that potentially contribute to the high comorbidity between these disorders. PubMed, Web of Science and Scopus databases were accessed and a systematic review of published studies was conducted. Several genes showed strong evidence for an association with MetS in patients with schizophrenia, including the fat mass and obesity associated gene (FTO), leptin and leptin receptor genes (LEP, LEPR), methylenetetrahydrofolate reductase (MTHFR) gene and the serotonin receptor 2C gene (HTR2C). Genetic association studies in complex disorders are convoluted by the multifactorial nature of these disorders, further complicating investigations of comorbidity. Recommendations for future studies include assessment of larger samples, inclusion of healthy controls, longitudinal rather than cross-sectional study designs, detailed capturing of data on confounding variables for both disorders and verification of significant findings in other populations. In future, big genomic datasets may allow for the calculation of polygenic risk scores in risk prediction of MetS in patients with schizophrenia. This could ultimately facilitate early, precise, and patient-specific pharmacological and non-pharmacological interventions to minimise CVD associated morbidity and mortality.

Metabolic syndrome in drug-naïve and drug-free patients with schizophrenia and in their siblings

OBJECTIVES

We tested the hypothesis that metabolic disturbances in people with schizophrenia exist as a part of the schizophrenic syndrome, even when the antipsychotic drug effect is eliminated. We aimed to determine the prevalence of metabolic syndrome among patients with schizophrenia who were antipsychotic drug-naive or drug-free and their siblings for comparison with healthy controls.

METHODS

One-hundred-two patients with schizophrenia (drug-naïve or drug-free), 64 siblings and 70 age-matched healthy subjects were recruited for this case-control study. Metabolic syndrome was assessed based on Adult Treatment Panel (ATP) III, adapted ATP III and International Diabetes Federation criteria. Student's t-tests, chi-squared tests, Kruskal-Wallis tests and Bonferroni corrections were used as appropriate.

RESULTS

The diagnoses of metabolic syndrome and metabolic disturbances as a subsyndromal state were found to be significantly more frequent in patients and their siblings than in the controls. Low levels of high-density lipoprotein cholesterol and disturbances in blood pressure put the patient group at risk for metabolic syndrome even before they were exposed to antipsychotic drugs.

CONCLUSIONS

Although antipsychotic drugs have consistently been related to disturbances of glucose and lipid metabolism in patients with schizophrenia, this study showed that patients with schizophrenia and their siblings are already at a high risk for metabolic syndrome independent of any antipsychotic effects. These individuals should be monitored regularly following a diagnosis of schizophrenia.

Increased cardiometabolic dysfunction in first-degree relatives of patients with psychotic disorders

INTRODUCTION

Elevated prevalence of comorbid cardio-vascular and metabolic dysfunction (CMD) is consistently reported in patients with severe psychotic disorders such as schizophrenia (SZ), schizoaffective (SZA) and bipolar disorder (BP-P). Since both psychosis and CMD are substantively heritable in nature, we attempted to investigate the occurrence of CMD disorders in first-degree relatives of probands with psychosis.

METHODS

Our sample included 861 probands with a diagnosis of SZ (n=354), SZA (n=212) and BP-P (n=295), 776 first-degree relatives of probands and 416 healthy controls. Logistic regression was used to compare prevalence of any CMD disorders (diabetes, hypertension, hyperlipidemia or coronary artery disease) across groups. Post hoc tests of independence checked for CMD prevalence across psychosis diagnosis (SZ, SZA and BP-P), both in relatives of probands and within probands themselves.

RESULTS

After controlling for potential confounders, first-degree relatives with (p<0.001) and without (p=0.03) Axis I non-psychotic or Axis- II cluster disorders were at a significant risk for CMD compared to controls. No significant difference (p=0.42) was observed in prevalence of CMD between relatives of SZ, SZA and BP-P, or between psychosis diagnoses for probands (p=0.25).

DISCUSSION

Prevalence of CMD was increased in the first-degree relatives of psychosis subjects. This finding suggests the possibility of overlapping genetic contributions to CMD and psychosis. Increased somatic disease burden in relatives of psychotic disorder probands points to need for early detection and preventive efforts in this population.

Schizophrenia: a systemic disorder

The concept of schizophrenia that is most widely taught is that it is a disorder in which psychotic symptoms are the main problem, and a dysregulation of dopamine signaling is the main feature of pathophysiology. However, this concept limits clinical assessment, the treatments offered to patients, research, and the development of therapeutics. A more appropriate conceptual model is that: 1) schizophrenia is not a psychotic disorder, but a disorder of essentially every brain function in which psychosis is present; 2) it is not a brain disease, but a disorder with impairments throughout the body; 3) for many patients, neuropsychiatric problems other than psychosis contribute more to impairment in function and quality of life than does psychosis; and, 4) some conditions that are considered to be comorbid are integral parts of the illness. In conclusion, students, patients, and family members should be taught this model, along with its implications for assessment, research, and therapeutics.

Behavioural and molecular endophenotypes in psychotic disorders reveal heritable abnormalities in glutamatergic neurotransmission

Psychotic disorders such as schizophrenia are biologically complex and carry huge population morbidity due to their prevalence, persistence and associated disability. Defined by features such as delusions and hallucinations, they involve cognitive dysfunction and neurotransmitter dysregulations that appear mostly to involve the dopaminergic and glutamatergic systems. A number of genetic and environmental factors are associated with these disorders but it has been difficult to identify the biological pathways underlying the principal symptoms. The endophenotype concept of stable, heritable traits that form a mechanistic link between genes and an overt expression of the disorder has potential to reduce the complexity of psychiatric phenotypes. In this study, we used a genetically sensitive design with individuals with a first episode of psychosis, their non-affected first-degree relatives and non-related healthy controls. Metabolomic analysis was combined with neurocognitive assessment to identify multilevel endophenotypic patterns: one concerned reaction times during the performance of cognitive and emotional tests that have previously been associated with the glutamate neurotransmission system, the other involved metabolites involved directly and indirectly in the co-activation of the N-methyl-D-aspartate receptor, a major receptor of the glutamate system. These cognitive and metabolic endophenotypes may comprise a single construct, such that genetically mediated dysfunction in the glutamate system may be responsible for delays in response to cognitive and emotional functions in psychotic disorders. This focus on glutamatergic neurotransmission should guide drug discovery and experimental medicine programmes in schizophrenia and related disorders.

Diabetes mellitus and severe mental illness: mechanisms and clinical implications

The prevalence of diabetes mellitus is twofold to threefold higher in people with severe mental illness (SMI) than in the general population, with diabetes mellitus affecting ∼12% of people receiving antipsychotics. The consequences of diabetes mellitus are more severe and frequent in people with SMI than in those without these conditions, with increased rates of microvascular and macrovascular complications, acute metabolic dysregulation and deaths related to diabetes mellitus. Multiple complex mechanisms underlie the association between diabetes mellitus and SMI; these mechanisms include genetic, environmental and disease-specific factors, and treatment-specific factors. Although antipsychotics are the mainstay of treatment in SMI, a causative link, albeit of uncertain magnitude, seems to exist between antipsychotics and diabetes mellitus. The principles of managing diabetes mellitus in people with SMI are similar to those for the general population and should follow currently established treatment algorithms. Lifestyle interventions are needed to reduce incident diabetes mellitus. In addition, improved uptake of opportunities to screen for this disease will reduce the high prevalence of undiagnosed diabetes mellitus. Currently, people with SMI receive poorer treatment for diabetes mellitus than the general population. Thus, health-care professionals in primary care, diabetes mellitus services and mental health teams have a responsibility to ensure that patients with SMI are not disadvantaged.

Elevated homocysteine level in first-episode schizophrenia patients--the relevance of family history of schizophrenia and lifetime diagnosis of cannabis abuse

Accumulating evidence indicates that elevated homocysteine (Hcy) level occurs in first-episode schizophrenia (FES) patients. We included 56 FES patients and 53 healthy controls (HC). Plasma level of Hcy was significantly higher in FES patients than HC (p = 0.044). In addition, plasma levels of high-density lipoproteins (HDL) and folate were significantly lower in FES than in HC (p < 0.001). Positive family history of schizophrenia was associated with lower plasma HDL (p = 0.041) and vitamin B12 (p = 0.017), as well as higher level of Hcy (p = 0.017). Patients with FES, who abused cannabis, had higher levels of Hcy (p = 0.017), as well as lower levels of vitamin B12 (p = 0.017) and HDL (p = 0.041). Plasma Hcy negatively correlated with duration of untreated psychosis (r = -0.272, p = 0.042). There was a positive correlation between Hcy level and the severity of negative symptoms (r = 0.363, p = 0.006) and general psychopathology (r = 0.349, p = 0.008) assessed using Positive and Negative Syndrome Scale (PANSS). Vitamin B12 level was negatively associated with the severity of negative symptoms (r = -0.406, p = 0.002), while folate level negatively correlated with general psychopathology score (r = -0.365, p = 0.006) in PANSS. These results indicate that the severity of one-carbon metabolism alterations and HDL deficiency might be associated with family history of schizophrenia and cannabis abuse. Lower vitamin B12 and folate along with elevated Hcy may influence the severity of FES psychopathology.

Coupling physical exercise with dietary glucose supplement for treating cognitive impairment in schizophrenia: a theoretical model and future directions

AIMS

Metabolic dysregulation may disrupt the complex neuroprotective mechanisms essential for brain health. Recent studies have pointed out the possible aetiological role of metabolic dysregulation in the onset of schizophrenia and the associated cognitive impairment. In this paper, we aimed to generate a theoretical model of how a combination of physical exercise and dietary glucose supplement may help to alleviate cognitive impairment in schizophrenia.

METHODS

Literature on metabolic dysregulation, especially insulin resistance, in relation to the onset of schizophrenia and the associated cognitive impairment is reviewed. The cognitive enhancement effects of physical exercise and dietary glucose supplement are then summarised. Finally, we propose a theoretical model based on the concerted effects of physical exercise and glucose supplement.

RESULTS

In general, the joint action of physical exercise and dietary glucose supplement could up-regulate glucose and insulin transport into the brain, as well as augmenting the release of insulin growth factor-1 and brain-derived neurotrophic factor. Physical exercise and glucose supplement could enhance energy supply and neuroplasticity in brain, subsequently leading to potential cognitive enhancement in schizophrenia. However, glucose supplement is not suitable for patients with abnormal metabolic profile.

CONCLUSIONS

The combination of physical exercise and glucose supplement has potential therapeutic values in treating cognitive impairment in schizophrenia. Further research is necessary to investigate the optimal patterns of exercise and doses of glucose for treating cognitive impairment in schizophrenia.

DNA hypermethylation of serotonin transporter gene promoter in drug naïve patients with schizophrenia

INTRODUCTION

Dysfunctional serotonin signaling has been linked to the pathogenesis of autism, obsessive compulsive disorder, mood disorders and schizophrenia. While the hypo-activity of serotonin signaling is involved in the pathogenesis of depression, anxiety and obsessive compulsive disorder; LSD, an agonist of serotonin type 2 receptor (5-HTR2A) induces psychosis. Therefore, anxiety and depressive disorders are treated by SSRIs which inhibit serotonin transporter (5-HTT) while psychotic disorders are controlled by drugs that block serotonin and/or dopamine receptors. Since genetic polymorphisms and epigenetic dysregulation of 5-HTT are involved in the pathogenesis of mental diseases, we analyzed DNA methylation of 5-HTT promoter in post-mortem brains and saliva samples of patients with schizophrenia (SCZ) and bipolar disorder (BD) to evaluate its potential application as a diagnostic and/or therapeutic biomarker in SCZ and BD.

METHODS

Whole genome DNA methylation profiling was performed for a total of 24 samples (including two saliva samples) using the Illumina 27K (for 12 samples) and 450K DNA methylation array platform (for another 12 samples), followed by bisulfite sequencing to identify candidate CpGs for further analysis. Quantitative methylation specific PCR (qMSP) was used to assess the degree of CpG methylation of 5-HTT promoter in 105 post-mortem brains (35 controls, 35 SCZ and 35 BD) and 100 saliva samples (30 controls, 30 SCZ, 20 BD and 20 first degree relatives of SCZ or BD). The U133 2.0 Plus Human Transcriptome array for a total of 30 post-mortem brain samples (each group 10) followed by quantitative real-time PCR was used to study 5-HTT expression in 105 post-mortem brain samples.

RESULTS

The qMSP analysis for 5-HTT promoter region showed DNA hypermethylation in post-mortem brain samples of SCZ patients (~30%), particularly in drug free patients (~60%, p=0.04). Similarly, there was a trend for DNA hypermethylation in antipsychotic free BD patients (~50%, p=0.066). qMSP analysis of DNA extracted from the saliva samples also exhibited hypermethylation of 5-HTT promoter in patients with SCZ (~30%, p=0.039), which was more significant in drug naïve SCZ patients (>50%, p=0.0025). However, the difference was not significant between the controls and unaffected first degree relatives of patients with SCZ (p=0.37) and versus patients using antipsychotic drugs (p=0.2). The whole genome transcriptome analysis of post-mortem brain samples showed reduced expression of 5-HTT in SCZ compared to the control subjects (~50%, p=0.008), confirmed by quantitative real-time PCR analysis (~40%, p=0.035) which was more significant in drug free SCZ patients (~70%, p=0.022).

CONCLUSION

A correlation between reduction in 5-HTT expression and DNA hypermethylation of the 5-HTT promoter in drug naïve SCZ patients suggests that an epigenetically defined hypo-activity of 5-HTT may be linked to SCZ pathogenesis. Furthermore, this epigenetic mark in DNA extracted from saliva can be considered as one of the key determinants in a panel of diagnostic and/or therapeutic biomarkers for SCZ.

Replicated evidence of absence of association between serum S100B and (risk of) psychotic disorder

BACKGROUND

S100B is a potential marker of neurological and psychiatric illness. In schizophrenia, increased S100B levels, as well as associations with acute positive and persisting negative symptoms, have been reported. It remains unclear whether S100B elevation, which possibly reflects glial dysfunction, is the consequence of disease or compensatory processes, or whether it is an indicator of familial risk.

METHODS

Serum samples were acquired from two large independent family samples (n = 348 and n = 254) in the Netherlands comprising patients with psychotic disorder (n = 140 and n = 82), non-psychotic siblings of patients with psychotic disorder (n = 125 and n = 94) and controls (n = 83 and n = 78). S100B was analyzed with a Liaison automated chemiluminescence system. Associations between familial risk of psychotic disorder and S100B were examined.

RESULTS

Results showed that S100B levels in patients (P) and siblings (S) were not significantly different from controls (C) (dataset 1: P vs. C: B = 0.004, 95% CI -0.005 to 0.013, p = 0.351; S vs. C: B = 0.000, 95% CI -0.009 to 0.008, p = 0.926; and dataset 2: P vs. C: B = 0.008, 95% CI -0.011 to 0.028, p = 0.410; S vs. C: B = 0.002, 95% CI -0.016 to 0.021, p = 0.797). In patients, negative symptoms were positively associated with S100B (B = 0.001, 95% CI 0.000 to 0.002, p = 0.005) in one of the datasets, however with failure of replication in the other. There was no significant association between S100B and positive symptoms or present use or type of antipsychotic medication.

CONCLUSIONS

S100B is neither an intermediate phenotype, nor a trait marker for psychotic illness.

Assessment of cardiovascular disease risk in patients with schizophrenia spectrum disorders in German psychiatric hospitals: results of the pharmacoepidemiologic CATS study

PURPOSE

Patients with severe mental illness are at high risk for metabolic and cardiac disorders. Thus, monitoring of cardiovascular risks is imperative and schedules for screening for lipids, glucose, body mass index (BMI), waist-hip ratio and blood pressure have been developed. We intended to analyze screening for metabolic disorders in German patients with schizophrenia spectrum disorders in routine psychiatric care.

METHODS

We included 674 patients with any F2 diagnosis in out- and inpatient settings and analyzed metabolic screening procedures as practiced under conditions of usual care.

RESULTS

Except BMI (54 %), all other values were documented only in a minority of patients: waist circumference (23 %), cholesterol (28 %), fasting glucose (19 %), triglycerides (25 %) and blood pressure (37 %). We found evidence for less than perfect quality of blood pressure measures. The group of patients who met the individual metabolic syndrome ATP III criteria was comparable to the US CATIE trial.

CONCLUSIONS

We conclude that frequency and quality of metabolic monitoring in German in- and outpatients settings are not in accordance with the respective recommendations. Similar to previous reports we found evidence for a high prevalence of metabolic disturbances in German patients with schizophrenia spectrum disorders.

The prevalence and mechanisms of metabolic syndrome in schizophrenia: a review

Metabolic syndrome (MetS), a constellation of central obesity, hypertension, dyslipidaemia and glucose intolerance, is highly prevalent in individuals with schizophrenia and conveys significant cardiovascular risk and mortality. Associated risk factors are female sex, some ethnic groups, advanced age, long duration of illness, smoking and exposure to antipsychotic agents. The prevalence of MetS varies across countries and psychiatric populations, and its development can be very rapid. Regular monitoring of all features of MetS is the cornerstone of its early detection and management. Future research needs to focus more on genetic determinants of MetS in the context of schizophrenic illness. This review aims to update the reader with the latest knowledge about the prevalence of MetS in schizophrenia and what might be the underlying pathophysiological mechanisms.

The prevalence of diabetes mellitus is increased in relatives of patients with a non-affective psychotic disorder

Patients with schizophrenia are more likely to develop diabetes mellitus (DM) compared to the general population. In relatives, however, an increased rate of DM has not consistently been reported. In this study, we compared DM rates in 1740 unaffected first- and second-/third-degree relatives of patients with a non-affective psychotic disorder to 1271 control subjects, by administering the Family Interview for Genetic Studies (FIGS). The prevalence of DM (6.1%) was increased in the relatives of patients as compared to the relatives of the healthy subjects (3.6%, OR=1.6, p=0.007). Our findings support the hypothesis of a familial, possibly genetic, link between DM and non-affective psychotic disorders.

Interventions for the metabolic syndrome in schizophrenia: a review

The metabolic syndrome (MetS) is an increasingly prevalent condition in people with schizophrenia. It remains highly prevalent in the general population in developed countries, but recently health promotion campaigns and greater awareness of the high associated mortality rates have resulted in improvements in the rates of cardiovascular risk factors. This is not the case for people with schizophrenia who continue to have more than twice the rates of MetS and significantly higher mortality rates than the general population. Various behavioural and pharmacological interventions have been used to improve conditions that are linked to MetS, mainly smoking and obesity. This review aims to provide an update of the latest knowledge about the behavioural, pharmacological and other interventions that might help to combat this life-threatening problem in people with schizophrenia.

Genetic correlates of medical comorbidity associated with schizophrenia and treatment with antipsychotics

PURPOSE OF REVIEW

High comorbidity rates for various medical conditions have been documented in schizophrenia, being explained by factors either inherent to the disease or associated with antipsychotic treatment. The aim of this study is to review the genetic factors contributing to medical comorbidity in schizophrenia.

RECENT FINDINGS

Based on clinical genetic studies in schizophrenia, comorbid impaired glucose tolerance/type 2 diabetes mellitus, most autoimmune disorders and cardiac autonomic dysregulation have the strongest evidence for familial predisposition. Similarly, of antipsychotic-induced adverse drug reactions, tardive dyskinesia, neuroleptic malignant syndrome, and antipsychotic-induced weight gain have some evidence for familial clustering. On the molecular genetic level, schizophrenia seems to share specific genes with type 2 diabetes mellitus and with autoimmune disorders. Various genes have been proposed to account for the reduced incidence of rheumatoid arthritis and cancer in schizophrenic patients and their relatives. Many pharmacogenetic association studies have pinpointed numerous, though often contradictory or poorly replicated, genes of modest effect size for tardive dyskinesia, neuroleptic malignant syndrome, clozapine-induced agranulocytosis, hyperprolactinaemia, antipsychotic-induced weight gain, and antipsychotic-induced QT prolongation.

SUMMARY

Unravelling the genetic underpinnings of medical comorbidity associated with schizophrenia and its treatment is expected to highlight new pathogenetic pathways in both schizophrenia and comorbid medical conditions, and introduce personalized treatment strategies for schizophrenia patients.

After six months of anti-psychotic treatment: Is the improvement in mental health at the expense of physical health?

INTRODUCTION

The morbidity and mortality due to cardiovascular causes in patients with schizophrenia is higher than in the general population, a fact that has been observed more since second generation anti-psychotics came into general use.

OBJECTIVES

To determine the incidence of metabolic syndrome in patients with a previously untreated first psychotic episode, as well as the prospective changes in the parameters that define the criteria of metabolic syndrome.

METHOD

An observational study with a prospective cohort design including patients who were admitted to the Acute Unit of Donostia Hospital.

RESULTS

A total of 21 patients were included in the study, of which 19 completed it. Just over one-quarter (26.3%) of the patients developed a metabolic syndrome at six months. Statistically significant differences were observed in the following parameters: 1) abdominal perimeter measurement with an increase of 14.6 cm at six months (P=.001); 2) triglyceride levels with a mean increase over the initial measurement of 48.99 mg/dl (P=.039); and 3) fasting blood glucose levels with a mean increase of 10.72 mg/dl (P=.001).

CONCLUSIONS

Significant changes were observed in metabolic parameters in a short period with the subsequent risk of associated cardiovascular events in a group of young patients. Actions are required directed at ensuring appropriate monitoring of these patients in order to measures to minimise the risks.

Is abnormal glucose tolerance in antipsychotic-naive patients with nonaffective psychosis confounded by poor health habits?

INTRODUCTION

Some but not all previous studies have found abnormal glucose tolerance or fasting glucose concentrations in antipsychotic-naïve patients with nonaffective psychosis. Our finding of abnormal glucose tolerance in patients with nonaffective psychosis could not be attributed to confounding by age, ethnicity, gender, smoking, socioeconomic status (SES), hypercortisolemia, or body mass index (BMI). However, other factors merit consideration as potential confounders of this association.

METHODS

An extended sample of newly diagnosed, antipsychotic-naive patients with schizophrenia and related disorders and matched controls were administered an oral glucose tolerance test. Confounding factors related to diet, self-care/access to care, and drug abuse were evaluated.

RESULTS

After accounting for the variance due to age, ethnicity, gender, smoking, SES, morning cortisol concentrations, BMI (or waist-hip ratio), our previous finding of abnormal glucose tolerance in these patients was confirmed. This difference could not be attributed to confounding by substance abuse; blood concentrations of vitamin B12, folate, or homocysteine; aerobic conditioning as measured by resting heart rate; or duration of untreated psychosis.

DISCUSSION

These results provide further evidence that people with schizophrenia and related disorders have abnormal glucose tolerance and an increased risk of diabetes prior to antipsychotic treatment and independent of health habits and access to care. Other measures should also be examined.

An association between high birth weight and schizophrenia in a Finnish schizophrenia family study sample

Longitudinal cohort studies have implicated an association between both low and high birth weight and schizophrenia. It has been suggested that schizophrenia associated genes could augment an individual's susceptibility to adverse prenatal and perinatal environmental events. We investigated the association between birth weight and schizophrenia in a large Finnish schizophrenia family study sample. We utilized the birth weight data of 1051 offspring from 315 Finnish families with at least one offspring with a diagnosis of schizophrenia. We used a multivariate COX frailty model to analyze the effect of birth weight on the risk of developing schizophrenia within the families. Using information from the Medication Reimbursement Register and patient interviews, we further investigated the association of maternal type 2 diabetes and schizophrenia risk among offspring. High birth weight (>4000g) was associated with a 1.68-fold increase in schizophrenia susceptibility. Maternal diabetes at the time of data collection, a proxy for gestational diabetes, was associated with a 1.66-fold increase in the risk of developing schizophrenia among offspring. Our results corroborate recent findings showing an association between high birth weight and schizophrenia. Our results also point to a potential birth-weight independent association between maternal type 2 diabetes and schizophrenia among offspring.

Schizophrenia as segmental progeria

Schizophrenia is associated with a variety of physical manifestations (i.e. metabolic, neurological) and despite psychotropic medication being blamed for some of these (in particular obesity and diabetes), there is evidence that schizophrenia itself confers an increased risk of physical disease and early death. The observation that schizophrenia and progeroid syndromes share common clinical features and molecular profiles gives rise to the hypothesis that schizophrenia could be conceptualized as a whole body disorder, namely a segmental progeria. Mammalian cells employ the mechanisms of cellular senescence and apoptosis (programmed cell death) as a means to control inevitable DNA damage and cancer. Exacerbation of those processes is associated with accelerated ageing and schizophrenia and this warrants further investigation into possible underlying biological mechanisms, such as epigenetic control of the genome.

Modulation ofTcf7l2 expression alters behavior in mice

The comorbidity of type 2 diabetes (T2D) with several psychiatric diseases is well established. While environmental factors may partially account for these co-occurrences, common genetic susceptibilities could also be implicated in the confluence of these diseases. In support of shared genetic burdens, TCF7L2, the strongest genetic determinant for T2D risk in the human population, has been recently implicated in schizophrenia (SCZ) risk, suggesting that this may be one of many loci that pleiotropically influence both diseases. To investigate whether Tcf7l2 is involved in behavioral phenotypes in addition to its roles in glucose metabolism, we conducted several behavioral tests in mice with null alleles of Tcf7l2 or overexpressing Tcf7l2. We identified a role for Tcf7l2 in anxiety-like behavior and a dose-dependent effect of Tcf7l2 alleles on fear learning. None of the mutant mice showed differences in prepulse inhibition (PPI), which is a well-established endophenotype for SCZ. These results show that Tcf7l2 alters behavior in mice. Importantly, these differences are observed prior to the onset of detectable glucose metabolism abnormalities. Whether these differences are related to human anxiety-disorders or schizophrenia remains to be determined. These animal models have the potential to elucidate the molecular basis of psychiatric comorbidities in diabetes and should therefore be studied further.