MTHFR genotype and differential evolution of metabolic parameters after initiation of a second generation antipsychotic: an observational study

Distribution of pharmacogene allele and phenotype frequencies in Brazilian psychiatric patients

Purpose: This work was designed to identify the pharmacogenetic profile of Brazilian psychiatric patients receiving psychoactive drug treatment according to ethnicity. Methods: Based on the GnTech® database, this cross-sectional study analyzed data from self-reported sociodemographic and genetic results from the next-generation sequencing panel composed of 26 pharmacogenes from 359 psychotropic drug users. Results: Variant frequencies of multiple pharmacogenes presented differences between ethnicities (CYP3A5, CYP2D6, CYP1A2, CYP2B6, CYP3A4, UGT1A4, UGT2B15, ABCB1 rs1045642, ADRA2A rs1800544, COMT rs4680, GRIK4 rs1954787, GSK3B rs334558, GSK3B rs6438552, HTR1A rs6295, HTR2A rs7997012, HTR2C rs1414334, MTHFR rs1801131, OPRM1 rs1799971 and 5-HTTLPR), endorsing the necessity of individual-level analyses in drug treatment. Conclusion: A discussion of pharmacogenomic test implementation in psychiatric clinical practice is needed to improve treatment choices, especially in Brazil, a multiethnic country.

Profiling the Skeletal Muscle Proteome in Patients on Atypical Antipsychotics and Mood Stabilizers

Atypical antipsychotics (AAP) are used in the treatment of severe mental illness. They are associated with several metabolic side effects including insulin resistance. The skeletal muscle is the primary tissue responsible for insulin-stimulated glucose uptake. Dysfunction of protein regulation within the skeletal muscle following treatment with AAPs may play a role in the associated metabolic side effects. The objective of this study was to measure protein abundance in the skeletal muscle of patients on long-term AAP or mood stabilizer treatment. Cross-sectional muscle biopsies were obtained from patients with bipolar disorder and global protein abundance was measured using stable isotope labeling by amino acid (SILAC) combined with high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). Sixteen patients completed muscle biopsies and were included in the proteomic analyses. A total of 40 proteins were significantly different between the AAP group and the mood stabilizer group. In-silico pathway analysis identified significant enrichment in several pathways including glucose metabolism, cell cycle, apoptosis, and folate metabolism. Proteome abundance changes also differed based on protein biological processes and function. In summary, significant differences in proteomic profiles were identified in the skeletal muscle between patients on AAPs and mood stabilizers. Future work is needed to validate these findings in prospectively sampled populations.

[Schizophrenia and cardiometabolic disorders]

The aim of this review is to analyze the basic biological mechanisms of comorbidity of schizophrenia and metabolic, cardiovascular diseases, which are not directly associated with external risk factors. The study of the general pathophysiological mechanisms of schizophrenia and metabolic disorders can provide a significant basis not only for the fundamentally novel therapeutic, preventive and diagnostic measures, but also for a better understanding of the etiopathogenesis of these diseases. It seems likely that schizophrenia represents a heterogeneous group with a varying genetic basis for both mental symptoms and neuroendocrine, inflammatory processes that form concomitant somatic disorders. Thus, the new integrated approaches to the study of this problem with the latest methods of genetic and molecular research are relevant.

Genetic and Metabolite Variability in One-Carbon Metabolism Applied to an Insulin Resistance Model in Patients With Schizophrenia Receiving Atypical Antipsychotics

Background: Patients with schizophrenia are at high risk of pre-mature mortality due to cardiovascular disease (CVD). Our group has completed studies in pharmacogenomics and metabolomics that have independently identified perturbations in one-carbon metabolism as associated with risk factors for CVD in this patient population. Therefore, this study aimed to use genetic and metabolomic data to determine the relationship between folate pharmacogenomics, one-carbon metabolites, and insulin resistance as measured using the homeostatic model assessment for insulin resistance (HOMA-IR) as a marker of CVD. Methods: Participants in this pilot analysis were on a stable atypical antipsychotic regimen for at least 6 months, with no diabetes diagnosis or use of antidiabetic medications. Participant samples were genotyped for MTHFR variants rs1801131 (MTHFR A1298C) and rs1801133 (MTHFR C677T). Serum metabolite concentrations were obtained with NMR. A least squares regression model was used to predict log(HOMA-IR) values based on the following independent variables: serum glutamate, glycine, betaine, serine, and threonine concentrations, and carrier status of the variant alleles for the selected genotypes. Results: A total of 67 participants were included, with a median age of 47 years old (IQR 42-52), 39% were female, and the median BMI was 30.3 (IQR 26.3-37.1). Overall, the model demonstrated an ability to predict log(HOMA-IR) values with an adjusted R ² of 0.44 and a p-value of < 0.001. Glutamate, threonine, and carrier status of the MTHFR 1298 C or MTHFR 677 T allele were positively correlated with log(HOMA-IR), whereas glycine, serine, and betaine concentrations trended inversely with log(HOMA-IR). All factors included in this final model were considered as having a possible effect on predicting log(HOMA-IR) as measured with a p-value < 0.1. Conclusions: Presence of pharmacogenomic variants that decrease the functional capacity of the MTHFR enzyme are associated with increased risk for cardiovascular disease, as measured in this instance by log(HOMA-IR). Furthermore, serine, glycine, and betaine concentrations trended inversely with HOMA-IR, suggesting that increased presence of methyl-donating groups is associated with lower measures of insulin resistance. Ultimately, these results will need to be replicated in a significantly larger population.

Meta-analysis of physical activity and effects of social function and quality of life on the physical activity in patients with schizophrenia

Schizophrenia patients have increased mortality and morbidity, mainly due to premature cardiovascular disease resulting from decreased physical activity (PA). However, which PA intensity is impaired in the patients and how factors such as social function and quality of life (QoL) are related to decreased PA is unknown. To assess PA, social function and QoL, the International Physical Activity Questionnaire (IPAQ), Social Functioning Scale (SFS) and Schizophrenia Quality of Life Scale (SQLS), respectively, were used in 109 schizophrenia patients and 69 healthy subjects. A meta-analysis comparing PA intensities (vigorous, moderate and light) assessed by the single PA measurement between schizophrenia patients and healthy subjects after including our case-control sample was performed. Furthermore, the effects of social function and QoL on each level of PA intensity were investigated in patients and controls. The meta-analysis in 212 schizophrenia patients and 132 healthy subjects revealed that patients showed lower total PA, particularly vigorous PA, than controls (I² = 0, Hedges' g = - 0.41, P = 2.80 × 10^-4). The decreased total PA was correlated with impaired total SFS scores (β = 0.24, P = 2.86 × 10^-3), withdrawal (β = 0.23, P = 3.74 × 10^-3) and recreation (β = 0.23, P = 3.49 × 10^-3) without significant heterogeneity between patients and controls. In contrast, the decreased total PA was affected by low independence-performance (β = 0.22, P = 0.034), employment/occupation (β = 0.27, P = 8.74 × 10^-3), psychosocial (β = - 0.24, P = 0.021) and motivation/energy (β = - 0.26, P = 0.013), but only in patients. Similar findings were obtained for vigorous PA but not moderate or light PA. Our findings suggest that the impaired vigorous PA in schizophrenia patients may be mediated by schizophrenia-specific factors of social functioning and QoL. Understanding these factors has important implications for increasing PA participation in schizophrenia patients.

The Effect of Long-Term Second-Generation Antipsychotics Use on the Metabolic Syndrome Parameters in Jordanian Population

Objectives: The aim of this study was to determine the incidence of metabolic syndrome in patients treated with second-generation antipsychotics (SGAs). Methods: In this retrospective study, we reviewed patients’ electronic medical records (EMRs) of all patients who received one SGA for at least six months, excluding patients who were taking other medications that are associated with significant effect on metabolic syndrome. Relevant clinical information was collected prior to starting the SGA and after six months of continuous use of the same SGA. Results: A total of 91 patients were included in the study. The majority of patients (72%) were diagnosed with schizophrenia. After six months of taking the SGA, 44% of patients experienced elevated systolic pressure, 54.9% had elevated triglyceride, and 31.9% had impaired glucose levels (p value < 0.05). Prior to initiating SGA therapy, 14.3% of patients had metabolic syndrome, while 37.4% had metabolic syndrome after six months of therapy, and it was more prominent in males compared to female patients (p value < 0.05). Conclusion: This study found a strong correlation between SGA use and the appearance of metabolic alterations, such as weight gain, glucose intolerance, and increased triglyceride levels. These findings highlight the importance of assessing metabolic deregulations to minimize SGA associated metabolic abnormalities.

The Effect of Long-Term Second-Generation Antipsychotics Use on the Metabolic Syndrome Parameters in Jordanian Population

Objectives: The aim of this study was to determine the incidence of metabolic syndrome in patients treated with second-generation antipsychotics (SGAs). Methods: In this retrospective study, we reviewed patients' electronic medical records (EMRs) of all patients who received one SGA for at least six months, excluding patients who were taking other medications that are associated with significant effect on metabolic syndrome. Relevant clinical information was collected prior to starting the SGA and after six months of continuous use of the same SGA. Results: A total of 91 patients were included in the study. The majority of patients (72%) were diagnosed with schizophrenia. After six months of taking the SGA, 44% of patients experienced elevated systolic pressure, 54.9% had elevated triglyceride, and 31.9% had impaired glucose levels (p value < 0.05). Prior to initiating SGA therapy, 14.3% of patients had metabolic syndrome, while 37.4% had metabolic syndrome after six months of therapy, and it was more prominent in males compared to female patients (p value < 0.05). Conclusion: This study found a strong correlation between SGA use and the appearance of metabolic alterations, such as weight gain, glucose intolerance, and increased triglyceride levels. These findings highlight the importance of assessing metabolic deregulations to minimize SGA associated metabolic abnormalities.

Smoking Rates and Number of Cigarettes Smoked per Day in Schizophrenia: A Large Cohort Meta-Analysis in a Japanese Population

Background

Cigarette smoking is consistently more common among schizophrenia patients than the general population worldwide; however, the findings of studies in Japan are inconsistent. Recently, the smoking rate has gradually decreased among the general population.

Methods

We performed a meta-analysis of smoking status in a large Japanese cohort of (1) 1845 schizophrenia patients and 196845 general population and (2) 842 schizophrenia patients and 766 psychiatrically healthy controls from 12 studies over a 25-year period, including 301 patients and 131 controls from our study.

Results

In our case-control sample, schizophrenia patients had a significantly higher smoking rate than healthy controls (P=.031). The proportion of heavy smokers (P=.027) and the number of cigarettes smoked per day (P=8.20×10-3) were significantly higher among schizophrenia patients than healthy controls. For the smokers in the schizophrenia group, atypical antipsychotics dosage was positively correlated with cigarettes per day (P=1.00×10-3). A meta-analysis found that schizophrenia patients had a higher smoking rate than the general population for both men (OR=1.53, P=.035; schizophrenia patients, 52.9%; general population, 40.1%) and women (OR=2.40, P=1.08×10-5; schizophrenia patients, 24.4%; general population, 11.8%). In addition, male schizophrenia patients had a higher smoking rate than male healthy controls (OR=2.84, P=9.48×10-3; schizophrenia patients, 53.6%; healthy controls, 32.9%), but the difference was not significant for women (OR=1.36, P=.53; schizophrenia patients, 17.0%; healthy controls,14.1%). Among both males and females, schizophrenia patients had a higher smoking rate than both the general population (OR=1.88, P=2.60×10-5) and healthy controls (OR=2.05, P=.018). These rates were not affected by the patients' recruitment year (P>.05). The cigarettes per day values of schizophrenia patients and the general population were 22.0 and 18.8, respectively.

Conclusions

Schizophrenia patients are approximately 2 times more likely to smoke than the general population and healthy controls based on data collected over a decade in Japan.

Single nucleotide polymorphism MTHFR677C>T and the severity of metabolic side effects of antipsychotics in patients with schizophrenia: the results of a pilot study

To predict the development of side effects and personalized selection of drug therapy, it seems relevant to study the association of individual genetic risk factors with undesirable side effects of antipsychotics in chronic patients with schizophrenia. Thereby the purpose of this study was to evaluate the association between the carriage of the T-allele of the single nucleotide genetic polymorphism MTHFR677C>T and the severity of the metabolic side effects of antipsychotics. As a result of the study a greater risk of developing components of the metabolic syndrome was revealed, as well as a significantly higher fasting blood glucose level in the group of carriers of the minor T-allele of polymorphism MTHFR677C>T.

The association between rehabilitation programs and metabolic syndrome in chronic inpatients with schizophrenia

The correlation between different rehabilitation programs and the prevalence of metabolic syndrome in people with schizophrenia is unclear. We tested the association in chronic inpatients with schizophrenia of a psychiatric hospital in Taiwan. Patients with schizophrenia and age from 20 to 65 years old were included. The criteria of metabolic syndrome were according to the adapted Adult Treatment Protocol for Asians. According to different types of rehabilitations, patients were divided into work group, occupational therapy group and daily activities group. A total of 359 chronic inpatients with schizophrenia were recruited. Participants had a mean age of 45.9 years and the prevalence of metabolic syndrome was 37.3%. There was a significantly higher prevalence of metabolic syndrome in the work group than in the daily activity group (adjusted odds ratio (aOR) = 1.91, 95% CI = 1.019-3.564, p < 0.05) after adjusted related confounders. Other factors associated with higher prevalence of metabolic syndrome included old age, female gender, low psychotic symptoms severity and clozapine user. This study identified a high prevalence of metabolic syndrome in chronic inpatients with schizophrenia especially in patients with good occupational function. Further investigation of the relationship between the occupational function and metabolic syndrome is necessary for chronic inpatients with schizophrenia.

Genetic Variation in One-Carbon Metabolism and Changes in Metabolic Parameters in First-Episode Schizophrenia Patients

BACKGROUND

In this study, we aimed to investigate the effects of polymorphisms in genes encoding 1-carbon metabolism enzymes on differential development of metabolic parameters during 12 weeks of treatment with second-generation antipsychotics in first-episode schizophrenia patients.

METHODS

The following polymorphisms in 1-carbon metabolism genes were genotyped: MTHFR (C677T and A1298C), MTHFD1 (G1958A), MTRR (A66G), and BHMT (G742A). A broad panel of metabolic parameters including body mass index, waist circumference, total cholesterol low and high density lipoproteins, triglycerides, homocysteine, folate, and vitamin B12 was determined.

RESULTS

There was a significant effect of the interaction between the MTHFR C677T polymorphism and time on body mass index and waist circumference in the allelic and genotype analyses. Indeed, patients with the MTHFR 677CC genotype had higher increase in body mass index and waist circumference compared with other corresponding genotypes or the MTHFR 677T allele carriers (CT and TT genotypes). In addition, patients with the MTHFR 677TT genotype had higher waist circumference in all time points. Similarly, patients with the MTHFR 677TT genotype had higher body mass index in all time points, but this effect was not significant after correction for multiple testing.

CONCLUSIONS

Our results indicate that the MTHFR C677T polymorphism may predict antipsychotic-induced weight gain. Effects of the MTHFR C677T polymorphism might be different in initial exposure to antipsychotics compared with long-term perspective.

Pharmacogenetic Associations of Antipsychotic Drug-Related Weight Gain: A Systematic Review and Meta-analysis

Although weight gain is a serious but variable adverse effect of antipsychotics that has genetic underpinnings, a comprehensive meta-analysis of pharmacogenetics of antipsychotic-related weight gain is missing. In this review, random effects meta-analyses were conducted for dominant and recessive models on associations of specific single nucleotide polymorphisms (SNP) with prospectively assessed antipsychotic-related weight or body mass index (BMI) changes (primary outcome), or categorical increases in weight or BMI (≥7%; secondary outcome). Published studies, identified via systematic database search (last search: December 31, 2014), plus 3 additional cohorts, including 222 antipsychotic-naïve youth, and 81 and 141 first-episode schizophrenia adults, each with patient-level data at 3 or 4 months treatment, were meta-analyzed. Altogether, 72 articles reporting on 46 non-duplicated samples (n = 6700, mean follow-up = 25.1wk) with 38 SNPs from 20 genes/genomic regions were meta-analyzed (for each meta-analysis, studies = 2-20, n = 81-2082). Eleven SNPs from 8 genes were significantly associated with weight or BMI change, and 4 SNPs from 2 genes were significantly associated with categorical weight or BMI increase. Combined, 13 SNPs from 9 genes (Adrenoceptor Alpha-2A [ADRA2A], Adrenoceptor Beta 3 [ADRB3], Brain-Derived Neurotrophic Factor [BDNF], Dopamine Receptor D2 [DRD2], Guanine Nucleotide Binding Protein [GNB3], 5-Hydroxytryptamine (Serotonin) Receptor 2C [HTR2C], Insulin-induced gene 2 [INSIG2], Melanocortin-4 Receptor [MC4R], and Synaptosomal-associated protein, 25kDa [SNAP25]) were significantly associated with antipsychotic-related weight gain (P-values < .05-.001). SNPs in ADRA2A, DRD2, HTR2C, and MC4R had the largest effect sizes (Hedges' g's = 0.30-0.80, ORs = 1.47-1.96). Less prior antipsychotic exposure (pediatric or first episode patients) and short follow-up (1-2 mo) were associated with larger effect sizes. Individual antipsychotics did not significantly moderate effect sizes. In conclusion, antipsychotic-related weight gain is polygenic and associated with specific genetic variants, especially in genes coding for antipsychotic pharmacodynamic targets.

Genetics of Common Antipsychotic-Induced Adverse Effects

The effectiveness of antipsychotic drugs is limited due to accompanying adverse effects which can pose considerable health risks and lead to patient noncompliance. Pharmacogenetics (PGx) offers a means to identify genetic biomarkers that can predict individual susceptibility to antipsychotic-induced adverse effects (AAEs), thereby improving clinical outcomes. We reviewed the literature on the PGx of common AAEs from 2010 to 2015, placing emphasis on findings that have been independently replicated and which have additionally been listed to be of interest by PGx expert panels. Gene-drug associations meeting these criteria primarily pertain to metabolic dysregulation, extrapyramidal symptoms (EPS), and tardive dyskinesia (TD). Regarding metabolic dysregulation, results have reaffirmed HTR2C as a strong candidate with potential clinical utility, while MC4R and OGFR1 gene loci have emerged as new and promising biomarkers for the prediction of weight gain. As for EPS and TD, additional evidence has accumulated in support of an association with CYP2D6 metabolizer status. Furthermore, HSPG2 and DPP6 have been identified as candidate genes with the potential to predict differential susceptibility to TD. Overall, considerable progress has been made within the field of psychiatric PGx, with inroads toward the development of clinical tools that can mitigate AAEs. Going forward, studies placing a greater emphasis on multilocus effects will need to be conducted.

Genetic Evaluation of Schizophrenia Using the Illumina HumanExome Chip

INTRODUCTION

Schizophrenia is a genetically heterogeneous disorder that is associated with several common and rare genetic variants. As technology involved, cost advantages of chip based genotyping was combined with information about rare variants, resulting in the Infinium HumanExome Beadchip. Using this chip, a sample of 493 patients with schizophrenia or schizoaffective disorder and 484 healthy controls was genotyped.

RESULTS

From the initial 242901 SNVs, 88306 had at least one minor allele and passed quality control. No variant reached genomewide-significant results (p<10(-8)). The SNP with the lowest p-value was rs1230345 in WISP3 (p = 3.05*10(-6)), followed by rs9311525 in CACNA2D3 (p = 1.03*10(-5)) and rs1558557 (p = 3.85*10(-05)) on chromosome 7. At the gene level, 3 genes were of interest: WISP3, on chromosome 6q21, a signally protein from the extracellular matrix. A second candidate gene is CACNA2D3, a regulator of the intracerebral calcium pathway. A third gene is TNFSF10, associated with p53 mediated apoptosis.

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.

DNA methylation, insulin resistance and second-generation antipsychotics in bipolar disorder

AIMS

This study aimed to assess the effect of second-generation antipsychotic (SGA) use and insulin resistance on a global measure of DNA methylation in patients diagnosed with bipolar disorder.

MATERIALS & METHODS

Subjects stable on medication (either mood stabilizer monotherapy or adjuvant SGAs) were assessed for insulin resistance. Global methylation levels were assessed in leukocyte DNA from whole blood using the Luminometric Methylation Assay. Multivariable linear regression was used to investigate the effect of insulin resistance and SGA use on DNA methylation.

RESULTS

A total of 115 bipolar I subjects were included in this study. The average age was 43.1 ±12.2 years and 73% were on SGAs. Average% global methylation was 77.0 ± 3.26 and was significantly influenced by insulin resistance, SGA use and smoking.

CONCLUSION

This is the first study to show a relationship between SGA use, insulin resistance and global DNA methylation. Further work will be needed to identify tissue- and gene-specific methylation changes.

Metabolic side effects and pharmacogenetics of second-generation antipsychotics in children

Second-generation antipsychotics (SGAs) are increasingly being used to treat children for a range of mental health conditions, for example, anxiety disorder, attention deficit hyperactivity disorder and bipolar disorder. SGA treatment is associated with weight gain and cardiometabolic side effects such as dyslipidemia, insulin resistance and elevated blood pressure, in some, but not all children. This review provides an overview of the potential role of pharmacogenomics in predisposing a child to unhealthy weight gain and cardiometabolic side effects with SGA treatment. Specifically, the review includes a synopsis of the evidence for cardiometabolic side effects in SGA-treated children, illustrating the extent and depth of the problem; summarizes the potential long-term consequences of developing cardiometabolic risk during childhood and highlights genetic variants that may be useful in predicting cardiometabolic side effects in SGA-treated children.

No association between genetic or epigenetic variation in insulin growth factors and antipsychotic-induced metabolic disturbances in a cross-sectional sample

AIM

Second-generation antipsychotics (SGA) are known to induce metabolic disturbances. Genetic pathways, such as the IGF pathway could be associated with increased metabolic syndrome (MetS). Additionally, IGF2 methylation varies as a function of environmental influences and is associated with schizophrenia and MetS. The current study aims to evaluate whether genetic and epigenetic variation in genes of the IGF pathway are associated with metabolic disturbances in patients under treatment with SGAs.

METHODS

Cross-sectional metabolic data from 438 patients with schizophrenia spectrum disorder was analyzed. Using the Sequenom MassARRAY iPLEX(TM) platform, 27 SNPs of the IGF1 and IGF2 genes and the IGF receptors IGF1R and IGF2R were genotyped. Methylation status of seven IGF2 CpG dinucleotides was evaluated using a Sequenom MALDI-TOF spectrometer.

RESULTS & CONCLUSION

There was a significant association between IGF2 methylation and genotype, but no significant association between genetic or epigenetic variability and metabolic parameters in the present study.

Comparison of study designs used to detect and characterize pharmacogenomic interactions in nonexperimental studies: a simulation study

OBJECTIVES

Adverse drug reactions are common, serious, difficult to predict, and may be influenced by genetics, prompting the increasing popularity of pharmacogenomic studies. Many pharmacogenomic studies are conducted in nonexperimental settings, yet little is known about the influence of confounding by contraindication. We, therefore, compared the two designs [the overall population (OPD) and the treated-only (TOD) design] by simulating a pharmacogenomic study of the ECG QT interval (QT).

METHODS

Simulations were informed by data from the Atherosclerosis Risk in Communities Study and a literature review examining QT, QT-prolonging drug use, and modification by single nucleotide polymorphisms (SNP). Drug treatment was assigned on the basis of age, sex, and QTlong, representing confounding by contraindication. QT was simulated as a function of drug treatment, one SNP, the drug-SNP interaction, and clinical covariates.

RESULTS

Failure to adjust for confounding by contraindication produced a varying degree of bias in the OPD, whereas the TOD was biased by the SNP main effect. For example, in the OPD, the false-positive proportion for the drug-SNP interaction was 5% across the range of SNP main effects (0-10 ms), but increased to 19% without adjusting for confounding by contraindication. In the TOD, the false-positive proportion increased to 89% with SNP main effects greater than 4 ms, although bias was reduced by 39% with adjustment for covariates affected by the SNP.

CONCLUSION

The potential for bias from confounding by contraindication (OPD) should be weighed against bias from SNP main effects (TOD) when selecting the study design that best suits the given context.

Effects of second-generation antipsychotics on selected markers of one-carbon metabolism and metabolic syndrome components in first-episode schizophrenia patients

Purpose

Alterations in one-carbon metabolism (OCM) have been repeatedly reported in schizophrenia. However, there is a scarcity of studies addressing the effects of antipsychotics on selected OCM markers in schizophrenia and provided results are inconsistent.

Methods

We recruited 39 first-episode schizophrenia (FES) patients and determined serum profile of total homocysteine (tHcy), folate, vitamin B12, lipoproteins and glucose at baseline and after 12 weeks of treatment with second-generation antipsychotics (SGA) including olanzapine and risperidone in monotherapy.

Results

After 12 weeks of treatment, all patients had significantly higher body mass index (BMI), serum levels of total cholesterol (TC), low-density lipoproteins (LDL), triglycerides (TG) and tHcy together with significantly lower levels of folate and vitamin B12. The analysis of differences between SGA revealed the same biochemical alterations in patients treated with olanzapine as in the whole group, while those receiving risperidone had no statistically significant changes in serum folate, vitamin B12 and TG. There was a significantly higher increase in BMI and TC in patients treated with olanzapine in comparison with those treated with risperidone. Patients receiving olanzapine had a higher decrease in vitamin B12 than those assigned to the treatment with risperidone. Changes in folate, vitamin B12, tHcy and TC levels were significant only in males, even after Bonferroni correction. Multiple regression analysis revealed that changes in tHcy levels are associated with gender and baseline metabolic parameters (BMI, glucose, TC, LDL and HDL) but not with selected SGA.

Conclusions

These results indicate that SGA may influence OCM, especially in first-episode schizophrenia (FES) males.

Electronic supplementary material

The online version of this article (doi:10.1007/s00228-014-1762-2) contains supplementary material, which is available to authorized users.

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.

Methylenetetrahydrofolate reductase gene variants and antipsychotic-induced weight gain and metabolic disturbances

Weight gain and metabolic disturbances represent serious side-effects in antipsychotic (AP) treatment, particularly with clozapine and olanzapine. The methylenetetrahydrofolate reductase (MTHFR) gene is a key determinant in the folate metabolism and previous studies reported a significant effect on AP-induced weight gain and related metabolic abnormalities. Thus, we investigated MTHFR gene variants and changes in several important metabolic parameters in AP-treated patients. In this study, two functional MTHFR polymorphisms, rs1801133 (C677T) and rs1801131 (A1298C), were investigated for changes in weight and metabolic parameters. Genotypic associations were evaluated in a large population (n = 347 including 66 first episode psychosis, FEP patients) treated mostly with clozapine and olanzapine. We did not detect any genotypic association with weight changes (p > 0.05) in our total sample and in the sample refined for ancestry and medication. In our allelic analyses, we observed a trend for the 677-C allele to be associated with weight gain in the total sample (p = 0.03). This effect appeared to be driven by the FEP patients where those carrying the C-allele gained, on average, twice as much weight. Exploratory analyses revealed a significant association between the C677T and the A1298C polymorphism with HDL cholesterol serum levels in patients (p = 0.031). Overall we did not detect a major effect of two functional MTHFR gene variants and AP-induced weight gain. However, our findings suggest an effect of the C677T polymorphism in FEP patients and changes in weight and cholesterol levels. Further investigations in a larger sample are required.

Pharmacogenetics in schizophrenia: a review of clozapine studies

OBJECTIVES

Clozapine is quite effective to treat schizophrenia, but its use is complicated by several factors. Although many patients respond to antipsychotic therapy, about 50% of them exhibit inadequate response, and ineffective medication trials may entail weeks of unremitted illness, potential adverse drug reactions, and treatment nonadherence. This review of the literature sought to describe the main pharmacogenetic studies of clozapine and the genes that potentially influence response to treatment with this medication in schizophrenics.

METHODS

We searched the PubMed database for studies published in English in the last 20 years using keywords related to the topic.

RESULTS AND CONCLUSIONS

Our search yielded 145 studies that met the search and selection criteria. Of these, 21 review articles were excluded. The 124 studies included for analysis showed controversial results. Therefore, efforts to identify key gene mechanisms that will be useful in predicting clozapine response and side effects have not been fully successful. Further studies with new analysis approaches and larger sample sizes are still required.

Methylenetetrahydrofolate reductase (MTHFR) 677C/T polymorphism is associated with antipsychotic-induced weight gain in first-episode schizophrenia

Genetic variants of the methylenetetrahydrofolate reductase (MTHFR) gene involved in homocysteine metabolism may be important predictors of antipsychotic drug-induced weight gain (AIWG). We tested whether two functional MTHFR polymorphisms are related to AIWG. Weight gain was studied in two cohorts of first-episode, initially drug-naive schizophrenia patients; Chinese Han (n = 182) and Spanish Caucasians (n = 72) receiving antipsychotics for 10 wk and 3 months respectively. Blood DNA was genotyped for 677C/T and 1298A/C MTHFR polymorphisms. Patients with the 677 CC genotype had a significantly greater increase in BMI compared to T-allele carriers in both Chinese (p = 0.012) and Spanish (p = 0.017) samples. The 677C/T MTHFR polymorphism showed an additive effect, but no significant interaction, with the -759C/T HTR2C polymorphism previously associated with AIWG. These results suggest that the 677C/T MTHFR polymorphism might, along with the -759C/T HTR2C polymorphism and other genetic factors, provide a useful marker for the important and limiting side effect of AIWG.

Association of ADRA2A and MTHFR gene polymorphisms with weight loss following antipsychotic switching to aripiprazole or ziprasidone

OBJECTIVES

Various genetic polymorphisms have been reported to be associated with antipsychotic-induced weight gain. In this study, we aimed to determine whether risk polymorphisms in 12 candidate genes are associated with reduction in body mass index (BMI) of patients following switching of antipsychotics to aripiprazole or ziprasidone.

METHODS

We recruited 115 schizophrenia patients with metabolic abnormalities and who have been on at least 1 year treatment with other antipsychotics; they were then switched to either aripiprazole or ziprasidone. They were genotyped, and their BMI monitored for 6 months.

RESULTS

Significant associations with reduction in BMI at 6 months following switching were found in two of these genes: with rs1800544 of the ADRA2A gene (CC + CG [-0.32 ± 1.41 kg/m²] vs GG [-1.04 ± 1.63 kg/m²], p = 0.013) and with rs1801131 of the MTHFR gene (AA [-0.36 ± 1.53] vs AC + CC [-1.07 ± 1.53], p = 0.015).

CONCLUSION

The study data indicated that carriage of the ADRA2A rs1800544 GG genotype and the MTHFR rs1801131 C allele are associated with BMI reduction in this population following switching of antipsychotics to aripiprazole and ziprasidone.

Integrating precision medicine in the study and clinical treatment of a severely mentally ill person

Background. In recent years, there has been an explosion in the number of technical and medical diagnostic platforms being developed. This has greatly improved our ability to more accurately, and more comprehensively, explore and characterize human biological systems on the individual level. Large quantities of biomedical data are now being generated and archived in many separate research and clinical activities, but there exists a paucity of studies that integrate the areas of clinical neuropsychiatry, personal genomics and brain-machine interfaces. Methods. A single person with severe mental illness was implanted with the Medtronic Reclaim(®) Deep Brain Stimulation (DBS) Therapy device for Obsessive Compulsive Disorder (OCD), targeting his nucleus accumbens/anterior limb of the internal capsule. Programming of the device and psychiatric assessments occurred in an outpatient setting for over two years. His genome was sequenced and variants were detected in the Illumina Whole Genome Sequencing Clinical Laboratory Improvement Amendments (CLIA)-certified laboratory. Results. We report here the detailed phenotypic characterization, clinical-grade whole genome sequencing (WGS), and two-year outcome of a man with severe OCD treated with DBS. Since implantation, this man has reported steady improvement, highlighted by a steady decline in his Yale-Brown Obsessive Compulsive Scale (YBOCS) score from ∼38 to a score of ∼25. A rechargeable Activa RC neurostimulator battery has been of major benefit in terms of facilitating a degree of stability and control over the stimulation. His psychiatric symptoms reliably worsen within hours of the battery becoming depleted, thus providing confirmatory evidence for the efficacy of DBS for OCD in this person. WGS revealed that he is a heterozygote for the p.Val66Met variant in BDNF, encoding a member of the nerve growth factor family, and which has been found to predispose carriers to various psychiatric illnesses. He carries the p.Glu429Ala allele in methylenetetrahydrofolate reductase (MTHFR) and the p.Asp7Asn allele in ChAT, encoding choline O-acetyltransferase, with both alleles having been shown to confer an elevated susceptibility to psychoses. We have found thousands of other variants in his genome, including pharmacogenetic and copy number variants. This information has been archived and offered to this person alongside the clinical sequencing data, so that he and others can re-analyze his genome for years to come. Conclusions. To our knowledge, this is the first study in the clinical neurosciences that integrates detailed neuropsychiatric phenotyping, deep brain stimulation for OCD and clinical-grade WGS with management of genetic results in the medical treatment of one person with severe mental illness. We offer this as an example of precision medicine in neuropsychiatry including brain-implantable devices and genomics-guided preventive health care.

Detection of metabolic syndrome in schizophrenia and implications for antipsychotic therapy : is there a role for folate?

In general, the presence of metabolic syndrome is associated with significant cardiovascular mortality and represents a growing public health concern in the USA. Patients with schizophrenia have a three times greater risk of death than the general population, with cardiovascular disease being the most common cause of this mortality. Use of atypical antipsychotics (AAPs) to treat schizophrenia contributes significantly to this cardiovascular risk. While several different clinical guidelines currently exist to monitor the metabolic consequences of AAP use, implementation is lacking. Because of under-monitoring of side effects and the lack of alternative treatment choices in schizophrenia, research has focused on identification of various biomarkers and pharmacogenomic targets to focus on the patients at greatest risk of metabolic syndrome, thus aiming to increase the efficacy and minimize the side effects of AAPs. This has led to several different lines of research. This review focuses on summarizing the differing metabolic syndrome criteria, monitoring guidelines for use of AAPs, and the role of folic acid as it relates to metabolic syndrome within the schizophrenia population. It concentrates not only on the pharmacogenomics of folic acid metabolism but also on its epigenetic interaction with the environment. From this work, genetic variation within both the methylenetetrahydrofolate reductase (MTHFR) gene and the catechol-O-methyltransferase (COMT) gene has been associated with an increased risk of metabolic syndrome in schizophrenia patients treated with AAPs. Furthermore, work on the combination of folate pharmacogenetics and epigenetics has uncovered relationships between methylation, schizophrenia disease, treatment type, and metabolic syndrome. Despite several areas of biomarker research into schizophrenia-related metabolic syndrome, translation into the clinical setting is still lacking, and further studies are needed to bridge this gap. In the future, folate supplementation may prove to be an easy and effective clinical tool for prevention and/or treatment of metabolic syndrome associated with AAP treatment, but clearly more research needs to be done in this area.

The multidimensional nature of metabolic syndrome in schizophrenia: lessons from studies of one-carbon metabolism and DNA methylation

Large data sets indicate that the prevalence of metabolic syndrome (MetS) is significantly higher in patients with schizophrenia in comparison with the general population. Given that interactions between genes and the environment may underlie the etiology of MetS in subjects with schizophrenia, it is feasible that epigenetic phenomena can serve as the etiological consensus between genetic and environmental factors. However, there is still a striking scarcity of studies aimed at investigating the role of aberrant DNA methylation in the development of MetS in this group of patients. This article provides an update on the epigenetics of schizophrenia and reviews studies on the role of one-carbon metabolism and aberrant DNA methylation in the development of MetS.

Relationships between physical fitness, physical activity, smoking and metabolic and mental health parameters in people with schizophrenia

Low physical fitness has been recognised as a prominent behavioural risk factor for cardiovascular diseases (CVD) and metabolic syndrome (MetS), and as an independent risk factor for all-cause mortality. No studies have systematically assessed physical fitness compared with a matched health control group in patients with schizophrenia. Eighty patients with schizophrenia and 40 age-, gender- and body mass index (BMI)-matched healthy volunteers were included. All participants performed an Eurofit test battery and filled out the International Physical Activity Questionnaire. Patients additionally had a fasting metabolic laboratory screening and were assessed for psychiatric symptoms. Patients with schizophrenia demonstrated significant differences from controls in whole body balance, explosive leg muscle strength, abdominal muscular endurance, and running speed. Inactive patients scored worse on most Eurofit items than patients walking for at least 30min per day. Low physical fitness was associated with illness duration, smoking, the presence of MetS and more severe negative, depressive and cognitive symptoms. Less physically active patients who smoke and suffer from high levels of negative, depressive and/or cognitive symptoms might benefit from specific rehabilitation interventions aimed at increasing physical fitness.

Is the prevalence of metabolic syndrome and metabolic abnormalities increased in early schizophrenia? A comparative meta-analysis of first episode, untreated and treated patients

We aimed to discover whether metabolic complications of schizophrenia (SZ) are present in first episode (FE) and unmedicated (UM) patients, in comparison with patients established on antipsychotic medication (AP).

METHOD

A systematic search, critical appraisal, and meta-analysis were conducted of studies to December 2011 using Medline, PsycINFO, Embase and experts. Twenty-six studies examined FE SZ patients (n = 2548) and 19 included UM SZ patients (n = 1325). For comparison we identified 78 publications involving 24 892 medicated patients who had chronic SZ already established on AP.

RESULTS

In UM, the overall rate of metabolic syndrome (MetS) was 9.8% using any standardized criteria. Diabetes was found in only 2.1% and hyperglycaemia (>100 mg/dl) in 6.4%. In FE, the overall MetS rate was 9.9%, diabetes was found in only 1.2%, and hyperglycaemia in 8.7%. In UM and FE, the rates of overweight were 26.6%, 22%; hypertriglyceridemia 16.9%, 19.6%; low HDL 20.4%, 21.9%; high blood pressure 24.3%, 30.4%; smoking 40.2%, 46.8%, respectively. In both groups all metabolic components and risk factors were significantly less common in early SZ than in those already established on AP. Waist size, blood pressure and smoking were significantly lower in UM compared with FE.

CONCLUSION

There is a significantly lower cardiovascular risk in early SZ than in chronic SZ. Both diabetes and pre-diabetes appear uncommon in the early stages, especially in UM. However, smoking does appear to be elevated early after diagnosis. Clinicians should focus on preventing initial cardiometabolic risk because subsequent reduction in this risk is more difficult to achieve, either through behavioral or pharmacologic interventions.

Prevalence of metabolic syndrome and metabolic abnormalities in schizophrenia and related disorders--a systematic review and meta-analysis

Individuals with schizophrenia have high levels of medical comorbidity and cardiovascular risk factors. The presence of 3 or more specific factors is indicative of metabolic syndrome, which is a significant influence upon future morbidity and mortality. We aimed to clarify the prevalence and predictors of metabolic syndrome (MetS) in adults with schizophrenia and related disorders, accounting for subgroup differences. A PRISMA systematic search, appraisal, and meta-analysis were conducted of 126 analyses in 77 publications (n = 25,692). The overall rate of MetS was 32.5% (95% CI = 30.1%-35.0%), and there were only minor differences according to the different definitions of MetS, treatment setting (inpatient vs outpatient), by country of origin and no appreciable difference between males and females. Older age had a modest influence on the rate of MetS (adjusted R(2) = .20; P < .0001), but the strongest influence was of illness duration (adjusted R(2) = .35; P < .0001). At a study level, waist size was most useful in predicting high rate of MetS with a sensitivity of 79.4% and a specificity of 78.8%. Sensitivity and specificity of high blood pressure, high triglycerides, high glucose and low high-density lipoprotein, and age (>38 y) are shown in supplementary appendix 2 online. Regarding prescribed antipsychotic medication, highest rates were seen in those prescribed clozapine (51.9%) and lowest rates of MetS in those who were unmedicated (20.2%). Present findings strongly support the notion that patients with schizophrenia should be considered a high-risk group. Patients with schizophrenia should receive regular monitoring and adequate treatment of cardio-metabolic risk factors.

Associations between sedentary behaviour and metabolic parameters in patients with schizophrenia

This study examined the association between sedentary behaviour and metabolic parameters among patients with schizophrenia. A total of 76 patients and 38 healthy age-, gender- and BMI-matched volunteers were included. Participants were asked for their overall sitting and physical activity behaviour using the International Physical Activity Questionnaire. Patients were additionally screened for psychiatric symptoms and extrapyramidal side-effects of antipsychotic medication. On average, patients with schizophrenia spent 8.5h per day sitting (versus 6.21h in healthy controls). Patients sitting more than 10.4h per day had a higher BMI, waist circumference and fasting glucose concentrations and experienced more negative and cognitive symptoms than those sitting less than 5.8h per day. Overall sitting time was associated with a significantly greater likelihood of metabolic syndrome. A stepwise backward-elimination multivariate regression analysis demonstrated that sitting time is a significant predictor for BMI. Current results suggest patients with schizophrenia may benefit from reducing total sitting time.

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.

The functional exercise capacity is correlated with global functioning in patients with schizophrenia

OBJECTIVE

The 6-minute walk test (6MWT) is commonly used to measure the functional exercise capacity in chronic patients with cardiovascular diseases. The purpose of this study was to determine whether the 6MWT is associated with the global assessment of functioning (GAF) score in patients with schizophrenia.

METHODS

A total of 68 male and 25 female in-patients with schizophrenia (34.6 ± 9.7 years; body mass index = 24.9 ± 4.4) performed a 6MWT and were assessed with the GAF scale and the Psychosis Evaluation tool for Common use by Caregivers (PECC).

RESULTS

The mean distance walked on the 6MWT was 587.3 ± 98.4 m, while the mean GAF score was 52.0 ± 10.4. The Pearson's correlation coefficient between the 6MWT and the GAF score was 0.59 (P < 0.001), indicating a moderate association between both measures. The 6MWT was also significantly related to negative (r = -0.45, P < 0.001), depressive (r = -0.48, P < 0.001) and cognitive (r=, P) symptoms and with body mass index (r = -0.31, P < 0.005), smoking behaviour (r = -0.36, P < 0.001)) and dose of antipsychotic medication (r = -0.38, P < 0.001).

CONCLUSION

Next to the GAF scale, clinicians in in-patient settings should consider incorporating the 6MWT into their test battery to measure the functional consequences of schizophrenia and its treatment.

Cardiometabolic risk and the MTHFR C677T variant in children treated with second-generation antipsychotics

Second-generation antipsychotics (SGAs) are increasingly being used to treat children with a variety of psychiatric illnesses. Metabolic syndrome (MetS), a risk factor for cardiovascular disease, is a side-effect of SGA-treatment. We conducted a cross-sectional study and assessed the association of the methylenetetrahydrofolate reductase (MTHFR) C677T variant with features of MetS in SGA-treated (n=105) and SGA-naïve (n=112) children. We targeted the MTHFR C677T variant, because it is associated with risk for cardiovascular disease, and features of MetS in adults without psychiatric illness. MetS in children is based on the presence of any three of the following: waist circumference ≥ 90th percentile for age and sex; plasma triglyceride ≥ 1.24 mmol l(-1); plasma high-density lipoprotein-cholesterol ≤ 1.03 mmol l(-1); systolic or diastolic blood pressure ≥ 90th percentile for age, sex, and height; and fasting glucose ≥ 5.6 mmol l(-1). We found that 15% of SGA-treated children had MetS compared with 2% of SGA-naïve children (OR 8.113, P<0.05). No effect of the MTHFR C677T variant on psychiatric diagnosis was observed. The MTHFR 677T allele was associated (P<0.05) with MetS (OR 5.75, 95% CI= 1.18-28.12) in SGA-treated children. Models adjusted for duration of SGA treatment, ethnicity, sex, age and use of other medications revealed a positive relationship between the MTHFR 677T allele and diastolic blood pressure Z-scores (P=0.001) and fasting plasma glucose (P<0.05) in SGA-treated children. These findings illustrate the high prevalence of MetS in SGA-treated children and suggest metabolic alterations associated with the MTHFR C677T variant may have a role in the development of MetS features in SGA-treated children.

Prevalence of metabolic syndrome in patients with schizophrenia, and metabolic changes after 3 months of treatment with antipsychotics--results from a German observational study

BACKGROUND

This observational study explored the prevalence of metabolic syndrome (MetS) in adult in- and outpatients with untreated or treated schizophrenia at baseline, and month-3 after initiation or switch of antipsychotic treatment.

METHODS

MetS-prevalence (AHA/NHLB-definition) was assessed and Clopper-Pearson 95% confidence intervals (CIs) were calculated. Factors associated with MetS were explored through univariate and multivariate logistic regressions (both visits).

RESULTS

MetS-prevalence was 44.3% (CI 39.8;48.9) at baseline and 49.6% (CI 45.0;54.2) at month-3. Previously unmedicated patients showed the lowest baseline MetS-prevalence (24.7%, CI 18.3;32.1). MetS-prevalence was not significantly different, regardless if patients previously received typical or atypical antipsychotics. Increased MetS-risk was associated with somatic comorbidity and non-smoking at both visits, and with non-psychiatric co-medication, male sex, and increased C-reactive protein at month-3.

CONCLUSIONS

At baseline, MetS was most prevalent in patients with previous antipsychotic medication. Limited metabolic changes were observed 3 months after switch/initiation of antipsychotic therapy.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: n.a.

Metabolic and cardiovascular adverse effects associated with antipsychotic drugs

Antipsychotic medications can induce cardiovascular and metabolic abnormalities (such as obesity, hyperglycemia, dyslipidemia and the metabolic syndrome) that are associated with an increased risk of type 2 diabetes mellitus and cardiovascular disease. Controversy remains about the contribution of individual antipsychotic drugs to this increased risk and whether they cause sudden cardiac death through prolongation of the corrected QT interval. Although some drug receptor-binding affinities correlate with specific cardiovascular and metabolic abnormalities, the exact pharmacological mechanisms underlying these associations remain unclear. Antipsychotic agents with prominent metabolic adverse effects might cause abnormalities in glucose and lipid metabolism via both obesity-related and obesity-unrelated molecular mechanisms. Despite existing guidelines and recommendations, many antipsychotic-drug-treated patients are not assessed for even the most easily measurable metabolic and cardiac risk factors, such as obesity and blood pressure. Subsequently, concerns have been raised over the use of these medications, especially pronounced in vulnerable pediatric patients, among whom their use has increased markedly in the past decade and seems to have especially orexigenic effects. This Review outlines the metabolic and cardiovascular risks of various antipsychotic medications in adults and children, defines the disparities in health care and finally makes recommendations for screening and monitoring of patients taking these agents.

Prediction of long-term metabolic effects of olanzapine and risperidone treatment from baseline body mass index in schizophrenia and bipolar disorder

Baseline body mass index (BMI), baseline BMI status (normal, overweight, obese) and early (1 month) BMI increases were tested as predictors of 6- and 12-month increases in glucose and lipid measures in 82 olanzapine (OLZ)- and 78 risperidone (RIS)-treated patients with schizophrenia, schizoaffective disorder, or bipolar disorder who participated in a 12-month randomized, prospective metabolic effects study. Baseline BMI predicted greater fasting glucose and HgbA1c levels at 12 months for both treatments. Early BMI change predicted fasting glucose levels at 6 months, but not HgbA1c or BMI, at either time point. For patients who received no concomitant mood stabilizers, early BMI change predicted 12 month HgbA1c values in the OLZ group, and 6- (but not 12-) month fasting glucose and HgbA1c values in the RIS group. Neither baseline BMI nor early BMI change consistently predicted increases in lipids with either drug. OLZ-treated patients with normal baseline BMI had greater increases in total cholesterol, triglycerides, and non-HDL-cholesterol than those who were overweight or obese. In conclusion, higher baseline BMI predicted adverse glycemic changes after 12 months with OLZ and RIS. Individuals with normal baseline BMI may be most susceptible to OLZ-induced hyperlipidosis. Frequency of metabolic screening should be independent of baseline BMI or rapid increases in BMI.

Dietary, lifestyle and pharmacogenetic factors associated with arteriole endothelial-dependent vasodilatation in schizophrenia patients treated with atypical antipsychotics (AAPs)

PURPOSE

Within schizophrenia cardiovascular disease (CVD) is highly prevalent secondary to atypical antipsychotic (AAP) use. Thorough assessments of diet, lifestyle, and endothelial functioning have not been done in this population. Omega 3 Fatty Acids (N-3 FAs) have garnered attention in relation to psychopathology as well as cardioprotection. This study examined the status of endothelial function within the schizophrenia population and determined pharmacogenetic, medication, dietary, and lifestyle factors associated with this functioning.

METHODS

Schizophrenia subjects were screened for the metabolic syndrome along with physical activity, smoking, and variants related to folate pharmacogenetics in this cross-sectional analysis. Arteriole endothelial-dependent vasodilatation was measured using non-invasive peripheral arterial tonometry (RH-PAT, EndoPAT2000). A 24h dietary food recall was used to construct intake profiles using the Nutrition Data Systems for Research software (NDSR). We examined associations between AAP use and RH-PAT values, and the influence of N-3 FA dietary intake on this measure. Preliminary data are reported in 83 subjects with a mean age (±s.d.) of 45.89 (±11.49), 64% were Caucasian (n=53), 64% were male (n=53), and 77% were receiving AAP treatment (n=63).

RESULTS

A significant positive relationship was found between RH-PAT values and N-3 FA intake (F=17.7(1,16), p=0.0007) in subjects not receiving AAPs. This relationship was lost in those treated with AAPs (F=0.25(1,43), p>0.6). Regression analysis confirmed the interaction effect of AAP treatment on the relationship between RH-PAT and N-3 FAs (p=0.0105). Endothelial dysfunction was also related to folate pharmacogenetic variants.

CONCLUSIONS

AAPs may counteract some vascular health benefits of a diet high in N-3 FAs. AAP use may necessitate a higher N-3 FA dose to regain these effects, but additional research is necessary to strengthen the preliminary findings. Pharmacogenetic variants related to folate and homocysteine metabolism may also increase endothelial dysfunction risk.

Pharmacogenetic testing to predict antipsychotic-induced weight gain: a systematic review

Weight gain is an important side effect of antipsychotic drugs. Since the high interindividual difference in weight gain suggests that genetic factors play a role in this weight gain, studies have tried to identify these factors. Most of these studies were carried out in the past few years and focussed largely on receptor polymorphisms, although some tried to explain the variation in weight gain by differences in pharmacokinetics. Unfortunately, the results of these association studies are often conflicting, which makes it hard to apply this genetic knowledge in daily clinical practice. This article summarizes the findings of these association studies and focuses on differences in study methodology in an attempt to explain why study results could have been conflicting. Furthermore, the feasibility of genetic testing in today’s clinical practice is discussed, using a model that consists of four components; analytical validity, clinical validity, clinical utility and ethical, legal and social issues.

Monitoring and prevalence rates of metabolic syndrome in military veterans with serious mental illness

Background

Cardiovascular disease is the leading cause of mortality among patients with serious mental illness (SMI) and the prevalence of metabolic syndrome—a constellation of cardiovascular risk factors—is significantly higher in these patients than in the general population. Metabolic monitoring among patients using second generation antipsychotics (SGAs)—a risk factor for metabolic syndrome—has been shown to be inadequate despite the release of several guidelines. However, patients with SMI have several factors independent of medication use that predispose them to a higher prevalence of metabolic syndrome. Our study therefore examines monitoring and prevalence of metabolic syndrome in patients with SMI, including those not using SGAs.

Methods and Findings

We retrospectively identified all patients treated at a Veterans Affairs Medical Center with diagnoses of schizophrenia, schizoaffective disorder or bipolar disorder during 2005–2006 and obtained demographic and clinical data. Incomplete monitoring of metabolic syndrome was defined as being unable to determine the status of at least one of the syndrome components. Of the 1,401 patients included (bipolar disorder: 822; schizophrenia: 222; and schizoaffective disorder: 357), 21.4% were incompletely monitored. Only 54.8% of patients who were not prescribed SGAs and did not have previous diagnoses of hypertension or hypercholesterolemia were monitored for all metabolic syndrome components compared to 92.4% of patients who had all three of these characteristics. Among patients monitored for metabolic syndrome completely, age-adjusted prevalence of the syndrome was 48.4%, with no significant difference between the three psychiatric groups.

Conclusions

Only one half of patients with SMI not using SGAs or previously diagnosed with hypertension and hypercholesterolemia were completely monitored for metabolic syndrome components compared to greater than 90% of those with these characteristics. With the high prevalence of metabolic syndrome seen in this population, there appears to be a need to intensify efforts to reduce this monitoring gap.

Clock genes and body composition in patients with schizophrenia under treatment with antipsychotic drugs

CONTEXT

In the healthy population, several pathways are known to exert an effect on basal metabolic factors. Previous studies have found associations between single nucleotide polymorphisms in clock genes or downstream hormone receptors such as the leptin receptor (LEPR) or glucocorticoid receptor (NR3C1) and obesity in the healthy population, but this association remains to be examined in patients with schizophrenia treated with antipsychotics.

OBJECTIVE

To assess anthropomorphic parameters in patients taking second-generation antipsychotics (SGA) as a function of nine polymorphisms in three core genes of the clock pathway, and two genes of downstream hormone receptors.

METHODS

Clinical parameters were evaluated in 261 patients with schizophrenia spectrum disorder. Polymorphisms in LEPR, MC3R, NR3C1, PER2 and SDC3 were genotyped. In order to control for multiple testing, permutation tests were used to generate corrected empirical p-values using the Max(T) procedure in PLINK.

RESULTS

A significant effect of the rs6196 polymorphism in the NR3C1 on weight (β=-4.18; SE=2.02; p=0.018), BMI (β=-1.88; SE=0.64; p=0.004), waist (β=-5.77; SE=1.75; p=0.001) and waist/hip ratio (β=-0.03; SE=0.012; p=0.009) was found. Permutation tests confirmed the findings for BMI (p=0.037) and waist (p=0.024). Carriers of the G allele consistently displayed better parameters than patients with the wild type allele. A weak effect of rs4949184 in SDC3 on BMI was found, but this did not sustain permutation testing (β=-1.27; SE=0.58; p=0.030, p=0.270 after permutations).

CONCLUSION

Variations in genes implicated in circadian regulation or its related downstream pathways may be important in the regulation of antropomorphic parameters in patients with schizophrenia during long-term treatment with SGA.

MTHFR and risk of metabolic syndrome in patients with schizophrenia

OBJECTIVE

Meta-analyses have implicated polymorphisms in MTHFR, encoding a critical enzyme in folate and homocysteine metabolism, in both schizophrenia and CVD.

METHOD

A possible association between the C677T and A1298C polymorphisms of the MTHFR gene on the one hand, and metabolic syndrome on the other, was examined in a naturalistic cohort of 518 patients with a schizophrenia spectrum disorder screened for metabolic disturbances at the Catholic University of Louvain, Belgium.

RESULTS

MTHFR A1298C, but not C677T, was associated with the metabolic syndrome, C/C genotypes having a 2.4 times higher risk compared to A/A genotypes (95% CI 1.25-4.76, p=0.009). Haplotype analysis revealed similar findings, showing greater risk for metabolic syndrome associated with the 677C/1298C haplotype compared to the reference 677C/1298A haplotype (OR 1.72, 95% CI 1.24-2.39, p=0.001). These associations were not explained by circulating folate levels. Differences between A1298C genotype groups were considerably greater in the subsample treated with clozapine or olanzapine (OR C/C versus A/A 3.87, 95% CI 1.51-9.96) than in subsample treated with any of the other antipsychotics (OR C/C versus A/A 1.30, 95% CI 0.47-3.74), although this did not formally reach statistical significance in the current cross-sectional study (gene-by-group interaction chi(2)=3.0, df=1, p=0.08).

CONCLUSION

These data provide evidence supporting an association between MTHFR and risk of metabolic syndrome in patients with schizophrenia. Prospective studies evaluating the course of metabolic outcomes after initiation of antipsychotic medication are needed to evaluate possible gene-by-treatment interaction more specifically.