Schizophrenia and diabetes: epidemiological data

Association between Empathy and Clinical Symptoms among Overweight and Non-Overweight Chinese Chronic Schizophrenia Patients

Patients with schizophrenia are afflicted by severe clinical symptoms and serious cognitive dysfunction. The aim of this study is to investigate the potential relationships between clinical symptoms and empathy and their variations between overweight and non-overweight schizophrenia patients. To address this problem, a group of 776 inpatients diagnosed with chronic schizophrenia (504 overweight patients and 272 non-overweight patients) was recruited. The Positive and Negative Syndrome Scale (PANSS) and its five-factor model were employed to assess clinical symptoms, while empathy levels were measured using the Interpersonal Reactivity Index (IRI). The overweight patients had lower education levels but higher positive symptoms than the non-overweight patients (all p < 0.05). In addition, the overweight patients performed significantly better with respect to empathy (FDR-corrected p < 0.05). Additional multiple regression analyses indicated significant associations between the total score of the IRI and PANSS negative symptoms, gender, and family history of psychiatric disorders among the overweight group; among non-overweight patients, there was a significant correlation between suicide and the total score of the IRI. This study provides evidence suggesting that chronic schizophrenia patients who are overweight may have distinct clinical characteristics, particularly with respect to their empathy, compared with non-overweight patients. Moreover, different variables are associated with empathy in different groups.

The type 2 diabetes mellitus susceptibility gene CDKAL1 polymorphism is associated with depressive symptom in first-episode drug-naive schizophrenic patients

BACKGROUND

Patients with schizophrenia have an increased prevalence of type 2 diabetes mellitus that has shown a significant association with the rs7754840 polymorphism in the gene encoding the cyclin-dependent kinase 5 (CDK5) regulatory subunit-associated protein 1-like 1 (CDKAL1).

OBJECTIVE

To examine whether this polymorphism was involved in the susceptibility in first-episode drug-naive schizophrenic patients (FDSP), and further influenced their clinical symptoms.

METHODS

This polymorphism was genotyped in 239 FDSP and 368 healthy controls. The clinical symptoms in FDSP were assessed using the Positive and Negative Syndrome Scale (PANSS) five-factor models.

RESULTS

There was no significant difference in the allelic and genotypic frequencies of this polymorphism between two groups (both p > 0.05) after adjusting for covariates. However, the PANSS depressive score significantly differed by genotype in FDSP after adjusting for covariates (F = 5.25, p = 0.006). This significant difference also persisted after Bonferroni correction (p < 0.05). FDSP with C/C genotype had significantly higher PANSS depressive score than those with C/G genotype (p = 0.007) and those with G/G genotype (p = 0.005). Moreover, further stepwise multivariate regression analysis showed the significant association between the rs7754840 polymorphism and PANSS depressive score in FDSP (β = -1.07, t = -2.75, p = 0.007).

CONCLUSIONS

Our findings demonstrated that although the CDKAL1 rs7754840 polymorphism did not contribute to the susceptibility to FDSP, it might be implicated in depressive symptoms in this patient group.

Differential diagnosis and comorbid physical illness of schizophrenia

Background: Schizophrenia is a neurodevelopmental disorder that generally develops during adolescence or early adulthood. However, differentiating it from psychosis caused by a physical illness is difficult due to the phenotypebased diagnostic system. In this review, differential diagnosis of schizophrenia and the comorbid physical illnesses of patients with schizophrenia will be discussed.Current Concepts: Psychotic symptoms can be caused by various physical illnesses, and patients with schizophrenia have many physical comorbidities. Symptoms of psychosis can also be expressed by physical illness including brain tumors, encephalitis, temporal lobe epilepsy, autoimmune disease, and genetic disease. For the differential diagnosis of other physical illnesses that can cause psychosis, biological tests are essential. Depending on the cause, antipsychotics and treatment of physical diseases are required. In addition, patients with schizophrenia have many comorbid medical conditions such as obesity, diabetes, cardiovascular disease, but the diagnosis rate is low, and the mortality is higher than that of the general population due to untreated medical diseases.Discussion and Conclusion: The differential diagnoses of schizophrenia and physical illness causing psychosis are important. To decrease the high mortality of patients with schizophrenia, periodic physical condition examinations and mental status examinations should be conducted.

Identification of Common Pathogenetic Processes between Schizophrenia and Diabetes Mellitus by Systems Biology Analysis

Schizophrenia (SCZ) is a psychiatric disorder characterized by both positive symptoms (i.e., psychosis) and negative symptoms (such as apathy, anhedonia, and poverty of speech). Epidemiological data show a high likelihood of early onset of type 2 diabetes mellitus (T2DM) in SCZ patients. However, the molecular processes that could explain the epidemiological association between SCZ and T2DM have not yet been characterized. Therefore, in the present study, we aimed to identify underlying common molecular pathogenetic processes and pathways between SCZ and T2DM. To this aim, we analyzed peripheral blood mononuclear cell (PBMC) transcriptomic data from SCZ and T2DM patients, and we detected 28 differentially expressed genes (DEGs) commonly modulated between SCZ and T2DM. Inflammatory-associated processes and membrane trafficking pathways as common biological processes were found to be in common between SCZ and T2DM. Analysis of the putative transcription factors involved in the regulation of the DEGs revealed that STAT1 (Signal Transducer and Activator of Transcription 1), RELA (v-rel reticuloendotheliosis viral oncogene homolog A (avian)), NFKB1 (Nuclear Factor Kappa B Subunit 1), and ERG (ETS-related gene) are involved in the expression of common DEGs in SCZ and T2DM. In conclusion, we provide core molecular signatures and pathways that are shared between SCZ and T2DM, which may contribute to the epidemiological association between them.

A review of the bidirectional relationship between psychiatric disorders and diabetes mellitus

The prevalence of type 2 diabetes is rising worldwide, including Saudi Arabia. Among patients with diabetes, 30% suffer from mental disorders, such as depression, schizophrenia, delirium, and substance misuse (for example, tobacco smoking). Moreover, these disorders appear to share a bidirectional relationship with diabetes. For example, the incidence of diabetes has been shown to be 2-4 times greater in patients with schizophrenia than in normal individuals; also, there is a known association between depression and diabetes. In this review, we focus specifically on the bidirectional relationship between diabetes and psychiatric disorders, including the effects of antipsychotic drugs.

Evidence for genetic contribution to the increased risk of type 2 diabetes in schizophrenia

The epidemiologic link between schizophrenia (SCZ) and type 2 diabetes (T2D) remains poorly understood. Here, we investigate the presence and extent of a shared genetic background between SCZ and T2D using genome-wide approaches. We performed a genome-wide association study (GWAS) and polygenic risk score analysis in a Greek sample collection (GOMAP) comprising three patient groups: SCZ only (n = 924), T2D only (n = 822), comorbid SCZ and T2D (n = 505); samples from two separate Greek cohorts were used as population-based controls (n = 1,125). We used genome-wide summary statistics from two large-scale GWAS of SCZ and T2D from the PGC and DIAGRAM consortia, respectively, to perform genetic overlap analyses, including a regional colocalisation test. We show for the first time that patients with comorbid SCZ and T2D have a higher genetic predisposition to both disorders compared to controls. We identify five genomic regions with evidence of colocalising SCZ and T2D signals, three of which contain known loci for both diseases. We also observe a significant excess of shared association signals between SCZ and T2D at nine out of ten investigated p value thresholds. Finally, we identify 29 genes associated with both T2D and SCZ, several of which have been implicated in biological processes relevant to these disorders. Together our results demonstrate that the observed comorbidity between SCZ and T2D is at least in part due to shared genetic mechanisms.

Genetic variants impacting metabolic outcomes among people on clozapine: a systematic review and meta-analysis

Clozapine is the gold standard medication for treatment refractory schizophrenia, but unfortunately, its use is also associated with many adverse metabolic side effects. There may be a strong genetic component to the development of these adverse effects. We undertook a systematic review to examine the evidence for genetic variation being associated with secondary metabolic outcomes in patients with schizophrenia on clozapine, under both longitudinal and cross-sectional study designs. We limited studies to those examining patients definitely taking clozapine, unlike prior reviews that have examined metabolic effects of patients taking a range of antipsychotic medications. We found associations with outcomes such as increases in BMI and metabolic syndrome for variants in genes such as LEP and HTR2C. Meta-analysis of rs381328 in HTR2C revealed that the presence of the T allele led to a 0.63 kg/m² (95% CI - 1.06 to - 0.19; p = 0.005) decrease in BMI compared to the C allele. Study and population heterogeneity and lack of statistical power among reviewed articles mean that evidence is lacking to warrant prophylactic genotyping of patients commencing clozapine to predict those at increased risk of developing adverse metabolic effects. Further efforts to establish collaborative consortia, consensus around study design and replication studies in independent populations should be encouraged.

[Schizophrenia and oral health]

Mental health is an essential component of general health. Schizophrenia is a severe and chronic mental illness that affects higher brain functions. It is characterized by the presence of a mental dissociation, dampened or inappropriate affects, hallucinations and delirium. Schizophrenia has also a negative impact on oral health. As schizophrenia affects 1% of the population, every practitioner concerned with oral sphere will be confronted one day or another with a patient suffering from this disease. It is therefore important to acquire essential notions. The aim of our work was to make an update about factors that may affect oral health in patients with schizophrenia.

Body mass index and blood glucose in psychiatric and general practice populations

Aims and method Using a retrospective observational approach, we aimed to discern whether there was a difference in metabolic parameters between psychiatric and general practice populations in the same locality. Second, we aimed to establish differences in metabolic parameters of patients taking olanzapine, clozapine or aripiprazole. Results Patients with psychiatric illness had a body mass index (BMI) comparable to that of the general practice population (28.7 v. 29.7 kg/m(2)), but blood glucose was significantly lower in the general practice population (4.8 v. 6.1 mmol/L). Olanzapine was associated with the lowest BMI (26.1 kg/m(2)) and aripiprazole the highest (32.2 kg/m(2)), with no difference in blood glucose between antipsychotics. Clinical implications Awareness of environmental factors and how they affect individuals is important and medications are not the only cause of metabolic effects. There may be a channelling bias present, meaning practitioners are cognisant of potential metabolic effects prior to prescribing. Overall monitoring of physical health is important regardless of potential cause.

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.

Altered metabolic parameters in association with antipsychotic medication use in diabetes: A population based case-control study

AIMS

This study assess differences in clinical variables in diabetes patients prescribed antipsychotic medication and determines relative schizophrenia prevalence in the diabetes population.

METHODS

This population-based case-control study utilizing Scotland's national diabetes registry (SCI-diabetes) and linked psychiatric hospital discharge data (SMR04) established diabetes phenotypes in a patient cohort prescribed long term antipsychotic medication (n=2362) (cases). Cases were matched 1:10 to diabetes patients not prescribed antipsychotic medication (controls) for BMI, gender; diabetes type; birth year; diagnosis date; smoking status. Sub-groups with defined schizophrenia (n=196) or bipolar disorder (n=190) were further examined. Schizophrenia prevalence in the diabetes versus general population was compared.

RESULTS

During follow up, antipsychotic prescription was associated with lower HbA1c (55.1 (95% CI 54.5-55.8) or 7.2 (95% CI 7.1-7.3)% vs 58.2 (58.0-58.4) mmol or 7.5 (95% CI 7.5-7.5)% p<0.001) lower serum total cholesterol, 4.2 (4.1-4.2) vs 4.3 (4.2-4.3) mmol/l, p<0.001, lower blood pressure (systolic 130 (130.17-131.29) vs 134 (134.3-134.7) mmHg, p<0.001), higher prescription of oral hypoglycaemic medication (42% (40-45) vs 38% (37-39) p<0.001), similar statin prescriptions (85% (81-89) vs 85% (84-86), p=0.55), and lower retinopathy rates (28% (25.6-30.5) vs 32% (31.5-33.1), p<0.001). HbA1c at diagnosis was similar (p=0.27). Schizophrenia prevalence was higher in the diabetes versus general population with differences across age groups (Scottish population versus diabetic population rate of 522.2 (522.1-522.3) versus 717.4 (703.4-731.9) per 100,000).

CONCLUSIONS

We confirm higher diabetes rates in schizophrenia up to age 70, similar attendance rates and clinical measurements that are not worse in a large well-matched population-based Scottish sample prescribed antipsychotic medication versus matched general diabetes patients.

Effect of age, family history of diabetes, and antipsychotic drug treatment on risk of diabetes in people with psychosis: a population-based cross-sectional study

BACKGROUND

Psychosis is associated with an increased risk of diabetes mellitus. A positive synergy between antipsychotic drug effects and a pre-existing liability to diabetes mellitus might explain the especially high relative risk of diabetes mellitus in young adults with psychosis. We aimed to assess the individual and joint effect of age, family history of diabetes mellitus, and currently prescribed antipsychotic drug treatment on risk for diabetes mellitus.

METHODS

In this study, we used data from the 2010 Australian National Survey of Psychosis-an observational study done at seven sites in five Australian states. We included data from 1155 people with psychosis aged 18-64 years who were in contact with psychiatric services and who gave a fasting blood sample to test for current diabetes mellitus. Using logistic regression, we modelled the association of diabetes mellitus with age, family history of diabetes mellitus, and current antipsychotic drug treatment. We compared model fit with and without two-way and three-way interaction terms and used likelihood ratio tests to establish which terms to include in the final model.

FINDINGS

After adjustment for older age, which was an independent risk factor, compared with not taking antipsychotic drugs, antipsychotic drug treatment was associated with diabetes mellitus only in those without a family history of diabetes mellitus (clozapine adjusted odds ratio [OR] 7·22, 95% CI 1·62-32·20, p=0·01; quetiapine 5·91, 1·33-26·30, p=0·02; aripiprazole 5·06, 0·86-29·64, p=0·07; risperidone 4·17, 0·90-19·24, p=0·07; and olanzapine 2·23, 0·45-11·06, p=0·32). Antipsychotic drug treatment was not associated with additional risk of diabetes mellitus in those with a family history (clozapine adjusted OR 1·51, 95% CI 0·64-3·54, p=0·34; quetiapine 1·09, 0·49-2·43, p=0·82; aripiprazole 0·43, 0·12-1·49, p=0·18; risperidone 1·12, 0·48-2·63, p=0·79; and olanzapine 0·67, 0·26-1·71, p=0·39).

INTERPRETATION

People with psychosis are at increased risk of diabetes mellitus if they have a family history of diabetes mellitus or if they have no family history of diabetes mellitus but are taking antipsychotic drugs. Increasing age increases risk but independently of family history or antipsychotic drug treatment. Clinicians should not think the absence of a family history of diabetes mellitus protects their patients from the diabetic side-effects of antipsychotics.

FUNDING

Australian Federal Government and Orygen.

Gender differences in cognitive deficits in schizophrenia with and without diabetes

This study investigated gender differences in cognition in schizophrenia with and without diabetes. Cognition was assessed in 263 individuals with schizophrenia with age range (40-68): 67 males and 34 females with schizophrenia with diabetes; and 125 males and 37 females with schizophrenia without diabetes according to the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Fasting glucose, hemoglobin A1c (HbA1c) and lipid levels were measured. Results showed that male individuals performed worse on most cognitive tasks, especially attention, in schizophrenia with than without diabetes. This result was not observed in female individuals. Also, individuals of both genders showed higher fasting glucose and HbA1c in schizophrenia with than without diabetes. In schizophrenia with diabetes, males had significantly worse cognition than females in all cognitive domains. Higher HbA1c, lower high-density lipoprotein, and an earlier age of onset of schizophrenia were found in males compared with female individuals. HbA1c was negatively associated with attention and the RBANS total score for males but not for females. In schizophrenia without diabetes, males showed worse performance in immediate and delayed memory than females. This study support cognition was worse for males with schizophrenia irrespective of whether they have diabetes. However, diabetes exemplified the gender differences, especially in attention.

An overview of diabetes management in schizophrenia patients: office based strategies for primary care practitioners and endocrinologists

Diabetes is common and seen in one in five patients with schizophrenia. It is more prevalent than in the general population and contributes to the increased morbidity and shortened lifespan seen in this population. However, screening and treatment for diabetes and other metabolic conditions remain poor for these patients. Multiple factors including genetic risk, neurobiologic mechanisms, psychotropic medications, and environmental factors contribute to the increased prevalence of diabetes. Primary care physicians should be aware of adverse effects of psychotropic medications that can cause or exacerbate diabetes and its complications. Management of diabetes requires physicians to tailor treatment recommendations to address special needs of this population. In addition to behavioral interventions, medications such as metformin have shown promise in attenuating weight loss and preventing hyperglycemia in those patients being treated with antipsychotic medications. Targeted diabetes prevention and treatment is critical in patients with schizophrenia and evidence-based interventions should be considered early in the course of treatment. This paper reviews the prevalence, etiology, and treatment of diabetes in schizophrenia and outlines office based interventions for physicians treating this vulnerable population.

Evidence for disturbed insulin and growth hormone signaling as potential risk factors in the development of schizophrenia

Molecular abnormalities in metabolic, hormonal and immune pathways are present in peripheral body fluids of a significant subgroup of schizophrenia patients. The authors have tested whether such disturbances also occur in psychiatrically ill and unaffected siblings of schizophrenia patients with the aim of identifying potential contributing factors to disease vulnerability. The subjects were recruited as part of the Genetic Risk and OUtcome of Psychosis (GROUP) study. The authors used multiplexed immunoassays to measure the levels of 184 molecules in serum from 112 schizophrenia patients, 133 siblings and 87 unrelated controls. Consistent with the findings of previous studies, serum from schizophrenia patients contained higher levels of insulin, C-peptide and proinsulin, decreased levels of growth hormone and altered concentrations of molecules involved in inflammation. In addition, significant differences were found in the levels of some of these proteins in siblings diagnosed with mood disorders (n=16) and in unaffected siblings (n=117). Most significantly, the insulin/growth hormone ratio was higher across all groups compared with the controls. Taken together, these findings suggest the presence of a molecular endophenotype involving disruption of insulin and growth factor signaling pathways as an increased risk factor for schizophrenia.

Predictors of type 2 diabetes in a nationally representative sample of adults with psychosis

Antipsychotic drugs such as clozapine and olanzapine are associated with an increased risk for type 2 diabetes, but relatively little is known about the relationship between risk factors for type 2 diabetes established in the general population and type 2 diabetes in people with psychosis. We estimated the prevalence of established risk factors and their association with type 2 diabetes in a nationally representative sample of people with an ICD-10 psychosis (N=1642) who gave a fasting blood sample (N=1155). Logistic regression was used to summarize associations adjusted for age and sex. In this sample, whose mean duration of psychosis was 14.7 years, 12.1% (13.1% of women and 11.5% of men) had type 2 diabetes at age 18-64 years based on current fasting blood glucose levels or treatment with a hypoglycaemic drug. Risk was greatly increased in young adults compared with the general population and peaked in middle age. Risk factors in the general population were common in people with psychosis and strongly associated with type 2 diabetes in those people. Treatment with clozapine was associated with an increased risk and treatment with olanzapine with a decreased risk for type 2 diabetes. The development of diabetes or pre-diabetes may therefore influence the likelihood of treatment with olanzapine over time. The strongest predictors of type 2 diabetes in a multivariate model were a body mass index of at least 40 and treated hypercholesterolemia, followed by a body mass index between 35 and 39.9, a family history of diabetes and treated hypertension. There was minimal to no confounding of the association between type 2 diabetes and current clozapine or olanzapine treatment, but neither association remained significant after adjustment for other predictors. Longitudinal relationships among predictors are likely to be complex, and previous antipsychotic drug treatment may at least partly explain risks associated with severe obesity, dyslipidemia and hypertension. A focus on weight loss is warranted in people with psychosis, but prevention strategies for type 2 diabetes should be broadened to include those with emerging dyslipidemia, hypertension and a family history of diabetes.

Emergency department utilization among Medicaid beneficiaries with schizophrenia and diabetes: the consequences of increasing medical complexity

OBJECTIVE

Individuals with both physical and mental health problems may have elevated levels of emergency department (ED) service utilization either for index conditions or for associated comorbidities. This study examines the use of ED services by Medicaid beneficiaries with comorbid diabetes and schizophrenia, a dyad with particularly high levels of clinical complexity.

METHODS

Retrospective cohort analysis of claims data for Medicaid beneficiaries with both schizophrenia and diabetes from fourteen Southern states was compared with patients with diabetes only, schizophrenia only, and patients with any diagnosis other than schizophrenia and diabetes. Key outcome variables for individuals with comorbid schizophrenia and diabetes were ED visits for diabetes, mental health-related conditions, and other causes.

RESULTS

Medicaid patients with comorbid diabetes and schizophrenia had an average number of 7.5 ED visits per year, compared to the sample Medicaid population with neither diabetes nor schizophrenia (1.9 ED visits per year), diabetes only (4.7 ED visits per year), and schizophrenia only (5.3 ED visits per year). Greater numbers of comorbidities (over and above diabetes and schizophrenia) were associated with substantial increases in diabetes-related, mental health-related and all-cause ED visits. Most ED visits in all patients, but especially in patients with more comorbidities, were for causes other than diabetes or mental health-related conditions.

CONCLUSION

Most ED utilization by individuals with diabetes and schizophrenia is for increasing numbers of comorbidities rather than the index conditions. Improving care in this population will require management of both index conditions as well as comorbid ones.

Cardiometabolic risk indicators that distinguish adults with psychosis from the general population, by age and gender

Individuals with psychosis are more likely than the general community to develop obesity and to die prematurely from heart disease. Interventions to improve cardiovascular outcomes are best targeted at the earliest indicators of risk, at the age they first emerge. We investigated which cardiometabolic risk indicators distinguished those with psychosis from the general population, by age by gender, and whether obesity explained the pattern of observed differences. Data was analyzed from an epidemiologically representative sample of 1,642 Australians with psychosis aged 18–64 years and a national comparator sample of 8,866 controls aged 25–64 years from the general population. Cubic b-splines were used to compare cross sectional age trends by gender for mean waist circumference, body mass index [BMI], blood pressure, fasting blood glucose, triglycerides, LDL, HDL, and total cholesterol in our psychosis and control samples. At age 25 individuals with psychosis had a significantly higher mean BMI, waist circumference, triglycerides, glucose [women only], and diastolic blood pressure and significantly lower HDL-cholesterol than controls. With the exception of triglycerides at age 60+ in men, and glucose in women at various ages, these differences were present at every age. Differences in BMI and waist circumference between samples, although dramatic, could not explain all differences in diastolic blood pressure, HDL-cholesterol or triglycerides but did explain differences in glucose. Psychosis has the hallmarks of insulin resistance by at least age 25. The entire syndrome, not just weight, should be a focus of intervention to reduce mortality from cardiovascular disease.

Diabetes and cognitive deficits in chronic schizophrenia: a case-control study

Cognitive impairment occurs in both schizophrenia and diabetes. There is currently limited understanding whether schizophrenia with diabetes has more serious cognitive deficits than schizophrenia without diabetes or diabetes only. This study assessed cognitive performance in 190 healthy controls, 106 diabetes only, 127 schizophrenia without diabetes and 55 schizophrenia with diabetes. This study was conducted from January 2008 to December 2010. Compared to healthy controls, all patient groups had significantly decreased total and five index RBANS scores (all p<0.01-p<0.001), except for the visuospatial/constructional index. Schizophrenia with diabetes performed worse than schizophrenia without diabetes in immediate memory (p<0.01) and total RBANS scores (<0.05), and showed a trend for decreased attention (p = 0.052) and visuospatial/constructional capacity (p = 0.063). Schizophrenia with diabetes performed worse than diabetes only in immediate memory (p<0.001) and attention (p<0.05), and showed a trend for decreased total RBANS scores (p = 0.069). Regression analysis showed that the RBANS had modest correlations with schizophrenia' PANSS scores, their duration of current antipsychotic treatment, and diagnosis of diabetes. Schizophrenia with co-morbid diabetes showed more cognitive impairment than schizophrenia without diabetes and diabetes only, especially in immediate memory and attention.

No association between the type 2 diabetes mellitus susceptibility gene, SLC30A8 and schizophrenia in a Chinese population

BACKGROUND

The co-occurrence of schizophrenia and type 2 diabetes mellitus (T2DM) has been well documented. Recent genome-wide association studies and meta-analyses have shown robust associations of the solute carrier family 30 member 8 (SLC30A8) gene variants with T2DM in various populations. We examined the involvement of the SLC30A8 in the susceptibility to schizophrenia in a Han Chinese population.

METHODS

The SLC30A8 rs13266634 gene polymorphism was genotyped in 837 chronic schizophrenic and 1109 unrelated healthy controls by using a case control design. We also assessed clinical symptoms.

RESULTS

There were no significant differences in the rs13266634 genotype (χ(2)  = 1.95, df = 2, p = 0.38) and allele (χ(2)  = 0.47, df = 1, p = 0.50) distributions between the patient and control groups. There was no association between rs13266634 and clinical symptoms.

CONCLUSION

The SLC30A8 gene variation does not appear to contribute a genetic basis for the co-occurrence of schizophrenia and T2DM.

[Psychotropic drugs and diabetes]

Psychotropic drugs, such as antipsychotics and antidepressants, are widely used substances which can display marked metabolic side effects. Psychiatric patients display increased morbidity and mortality which, besides disease specific factors, may be attributed to metabolic side effects of psychotropic drugs. Commonly observed side effects of antipsychotics are weight gain as well as disturbances in glucose and lipid metabolism. Additionally, antipsychotics have been shown to increase diabetes risk. Also, the use of some of the antidepressant substances is associated with an increased diabetes risk. However, large inter-substance variations have been observed. Conversely, diabetics have an increased risk of depression. Metabolic side effects of psychotropic drugs pose a serious impairment for psychiatric patients and their management can play a pivotal role in therapeutic compliance and success. This review aims to give an overview of metabolic side effects of commonly used psychotic drugs and to give an insight into possible underlying mechanisms.

Gender differences in the prevalence of diabetes mellitus in chronic hospitalized patients with schizophrenia on long-term antipsychotics

Gender-specific relationships between diabetes mellitus (DM) and schizophrenia have previously received little systematic study. The results showed that the overall DM prevalence was 20% with rates of 17% (58/343) in males and 27% (46/172) in females (p<0.01). Furthermore, increased body mass index (BMI), abdominal obesity and antipsychotic types were predictors of diabetes in these chronic schizophrenic patients.

Incidence of diabetes in patients with schizophrenia: a population-based study

OBJECTIVE

To detect the incidence of diabetes in patients with schizophrenia in Taiwan.

METHODS

The National Health Research Institute provided a database of 1 million random subjects for study, from which we drew a random sample of 617 068 subjects aged 18 years and older in the year 2000. Subjects who had at least one service claim during this year, with a primary diagnosis of schizophrenia, diabetes, or with a prescription for treatment of diabetes, were identified. We compared initial diagnosis of diabetes between patients with schizophrenia and the general population in 2000. We also followed a cohort of subjects with schizophrenia from 2000 to 2005.

RESULTS

The incidence of diabetes was higher in patients with schizophrenia than in the general population (1.46% and 1.12%, respectively; OR 1.47; 95% CI 1.09 to 1.97) in 2000. Compared with the general population, patients with schizophrenia showed a higher incidence of diabetes in the group aged 18 to 29 years; among females; among those with insurance of more than US$1281; among those living in the northern region; and among those residing in urban areas. The average annual incidence of diabetes in patients with schizophrenia was 1.84% from 2000 to 2005. Higher incidence of diabetes in patients with schizophrenia was associated with increased age, females, hypertension, and hyperlipidemia.

CONCLUSIONS

Patients with schizophrenia had a higher incidence of diabetes for the youngest adult age group and for females than for the general population. Increased age, females, hypertension, and hyperlipidemia were risk factors of diabetes in patients with schizophrenia.

Rethinking the genetic basis for comorbidity of schizophrenia and type 2 diabetes

The co-occurrence of schizophrenia (SCZ) and type 2 diabetes mellitus (T2D) has been well documented. This review article focuses on the hypothesis that the co-occurrence of SCZ and T2D may be, at least in part, driven by shared genetic factors. Previous genetic studies of T2D and SCZ evidence have disclosed a number of overlapped risk loci. However, the putative common genetic factors for SCZ and T2D remain inconclusive due to inconsistent findings. A systemic review of methods of identifying genetic loci contributing to the comorbidity link between SCZ and T2D is hence needed. In the current review article, we have discussed several different approaches to localizing the shared susceptibility genes for these two diseases. To begin with, one could start with probing the gene involved in both glucose and dopamine metabolisms. Additionally, hypothesis-free genome-wide association studies (GWAS) may provide more clues to the common genetic basis for these two diseases. Genetic similarities inferred from GWAS may shed some light on the genetic mechanism underlying the comorbidity link between SCZ and T2D. Meanwhile, endophenotypes (e.g., adiponectin level in T2D and working memory in SCZ) may serve as alternative phenotypes that are more directly influenced by genes than target diseases. Hence, endophenotypes of these diseases may be more tractable to identification. To summarize, novel approaches are needed to dissect the complex genetic basis of the comorbidity of SCZ and T2D.

Prevalence of diabetes and antipsychotic prescription patterns in patients with schizophrenia: a nationwide retrospective cohort study

INTRODUCTION

Despite an increasing concern that atypical antipsychotics seem to have a stronger diabetogenic risk than conventional antipsychotics, little information is available on the prevalence of diabetes among schizophrenia patients, and prescription patterns for patients with comorbid schizophrenia and diabetes in Japan.

OBJECTIVES

To compare the prevalence of diabetes between schizophrenia patients and the general population and to investigate whether diabetes status correlates the prescription patterns of antipsychotics at hospital discharge.

METHODS

Schizophrenia patients who were discharged between April 2004 and March 2005 and who continued to receive outpatient treatment from 526 hospitals were included in this retrospective open cohort study. We collected information about the doctor diagnosis of diabetes during hospitalization, and drug prescriptions for schizophrenia at hospital discharge using medical charts.

RESULTS

The overall prevalence of diabetes was 8.6% among patients with schizophrenia. Compared with the general population, the estimates of diabetes prevalence in the schizophrenia population were 2.6-10.8 percentage point higher among males aged 30-49 years, and 1.9-9.9 percentage point higher among females aged 40-59 years. The odds of being prescribed conventional antipsychotics were about 2 times higher among patients with diabetes than without diabetes, relative to atypical and combination of conventional and atypical antipsychotics. These results were robust across various sensitivity analyses.

CONCLUSION

When treating schizophrenia patients with preexisting diabetes, psychiatrists need to monitor the occurrence of diabetes regularly regardless of antipsychotic class, strike a balance, and provide the most efficacious antipsychotic medication.

Prevalence of metabolic syndrome among an Iranian cohort of inpatients with schizophrenia

BACKGROUND

Cardiovascular disease is an important cause among natural causes of death in schizophrenic patients. The metabolic syndrome (MetS) has been associated with an increased risk of morbidity and mortality due to cardiovascular disease. There are limited if any data on prevalence of MetS in Iranian patients with schizophrenia.

METHODS

Between December 2007 and May 2008, all consecutive patients with schizophrenia hospitalized at our university psychiatry hospital were entered in the study. The prevalence of MetS was evaluated based on the National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP-III), the adapted ATP-III guidelines (ATP-III A), and the recently suggested criteria by International Diabetes Federation (IDF).

RESULTS

Of the study participants, 223 were men (59.9%) and 149 women (40.1%). Overall prevalence of the MetS according to the different definitions were 27.4% (ATP-III), 37.6% (ATP-III A), and 38.7% (IDF), which was over 30% more than the prevalence of MetS in the Iranian general population. The MetS was much more prevalent in women which mainly related to the fact that women had central obesity more frequently.

CONCLUSIONS

Our results confirm the high prevalence of MetS in schizophrenic patients. These results clearly suggest the necessity for a careful monitoring and management of metabolic risk factors in this high-risk population.

An evaluation of monitoring practices in patients on second generation antipsychotics

OBJECTIVE

Treatment with second generation antipsychotics (SGAs) can increase the risk of patients with schizophrenia developing obesity, hyperlipidaemia and diabetes. Routine monitoring is recommended, but clinical practice suggests monitoring is not conducted at a rate necessary for these comorbidities. The aim was to audit what proportion of patients were having their weight, height, girth, body mass index, lipids and blood sugar levels monitored and recorded.

METHOD

An audit of patients with schizophrenia, discharged from three psychiatric wards, was conducted. Two data sheets were recorded for every patient and inter-rater reliability was calculated. Data were then entered into SPSS and statistical significance calculated.

RESULTS

The sample consisted of 93 patients; SGAs were taken by 31% of admitted and 88% of discharged patients. Of these, 65% had their weight recorded, 61% height, 31% random blood sugar levels, 3% postprandial blood sugar levels, 2% glycosylated haemoglobin, and 7.5% cholesterol and triglycerides. Girth and BMI were not recorded. Abnormalities were detected in 29% of recorded BSL and 2% of recorded cholesterol.

CONCLUSIONS

Patients with schizophrenia on antipsychotics have an alarmingly low rate of monitoring of these common adverse effects and comorbidities. Clinicians need to be aware of this, so that they can improve their practice.

Prevalence of diabetes in patients with schizophrenia in Taiwan: a population-based National Health Insurance study

OBJECTIVE

We conducted this study to investigate the prevalence and correlates of diabetes in patients with schizophrenia in Taiwan.

METHODS

The National Health Research Institute provided a database of 1,000,000 random subjects for study. We obtained a random sample aged 18 years and over of 766,427 subjects in 2005. Those study subjects who had at least one service claim during this year for either ambulatory or inpatient care, with a primary diagnosis of schizophrenia or with a prescription for treatment of diabetes, were identified.

RESULTS

The prevalence of diabetes in patients with schizophrenia was higher than in the general population (7.90% vs. 5.57%, odds ratio [OR], 1.81; 95% confidence interval [CI], 1.61-2.03). Compared with the general population, patients with schizophrenia revealed a higher prevalence of diabetes in all age groups, except age 70 or more years; among females (10.30% vs. 5.42%, p<0.001), and males (5.93% vs. 5.73%, p<0.001); among all insurance amount groups; among those living in the northern (7.56% vs. 4.89%, p<0.001), central (8.26% vs. 5.61%, p<0.001), southern regions (8.45% vs. 6.62%, p<0.001); and among residents living in urban (8.18% vs. 5.19%, p<0.001) and rural areas (7.99% vs. 6.15%, p<0.001).

CONCLUSIONS

Patients with schizophrenia had a much higher prevalence of diabetes in younger adult age groups and in females than in the general population, a finding that deserves further biological and psychosocial study in the future.

Polymorphisms in human endogenous retrovirus K-18 and risk of type 2 diabetes in individuals with schizophrenia

Type 2 diabetes is a major health problem in individuals with schizophrenia. The genetic basis of diabetes risk in individuals with schizophrenia has not been previously defined. We measured polymorphisms in a human endogenous retrovirus, Herv K-18, which is located in the CD48 signaling lymphocyte activating (SLAM) gene on chromosome 1. The study population consisted of 229 individuals with schizophrenia, 29 of whom had a history of type 2 diabetes, as well as 136 control individuals without a history of a psychiatric disorder or type 2 diabetes. We found that a haplotype defined by 2 polymorphisms in the envelope region of Herv K-18 is highly associated with type 2 diabetes in a population of 229 individuals with schizophrenia, with an odds ratio of 9.0 (95% confidence limits 2.3-34.7, p<.001) adjusted for race, gender and type of antipsychotic medication. Lower levels of association were found in other polymorphisms located in the 3'untranslated region of Herv K-18 and in adjacent loci in CD48. Polymorphisms in endogenous retroviruses which are located near immunomodulatory genes may constitute risk factors for diabetes in individuals with schizophrenia.

Diabetes and schizophrenia - effect of disease or drug? Results from a randomized, double-blind, controlled prospective study in first-episode schizophrenia

OBJECTIVE

There have been innumerable advances in the pharmacotherapy of schizophrenia, but problems have emerged hand-in-glove, such as the presence of treatment-emergent glucose intolerance and frank diabetes mellitus (DM).

METHOD

Medication-naïve patients with schizophrenia (n = 99) underwent baseline fasting and 2 h post-prandial plasma glucose measurements repeated after 6 weeks after randomization to receive olanzapine, risperidone or haloperidol. The results were compared with a matched healthy control group.

RESULTS

A significant difference (P = 0.002) in baseline 2 h post-prandial blood sugar (PPBS) was noted between the control group and the treatment group along with a significant increase in weight (P < 0.001), fasting blood sugar (P = 0.01) and 2 h PPBS (P < 0.001) from baseline to endpoint between the groups. A statistical significance in the incidence of DM at endpoint by the WHO criteria (10.1%) was also noted.

CONCLUSION

Male patients with schizophrenia are liable to develop DM. Antipsychotic treatment leads to the development of DM in a significant 10.1% within 6 weeks.

Atypical antipsychotic-induced metabolic side effects: insights from receptor-binding profiles

Atypical antipsychotic drugs offer several notable benefits over typical antipsychotics, including greater improvement in negative symptoms, cognitive function, prevention of deterioration, and quality of life, and fewer extrapyramidal symptoms (EPS). However, concerns about EPS have been replaced by concerns about other side effects, such as weight gain, glucose dysregulation and dyslipidemia. These side effects are associated with potential long-term cardiovascular health risks, decreased medication adherence, and may eventually lead to clinical deterioration. Despite a greater understanding of the biochemical effects of these drugs in recent years, the pharmacological mechanisms underlying their various therapeutic properties and related side effects remain unclear. Besides dopamine D(2) receptor antagonism, a characteristic feature of all atypical antipsychotic drugs, these agents also bind to a range of non-dopaminergic targets, including serotonin, glutamate, histamine, alpha-adrenergic and muscarinic receptors. This review examines the potential contribution of different receptors to metabolic side effects associated with atypical antipsychotic treatment for all seven agents currently marketed in the United States (risperidone, olanzapine, quetiapine, ziprasidone, aripiprazole, paliperidone and clozapine) and another agent (bifeprunox) in clinical development at the time of this publication.