Adjunctive Lurasidone Suppresses Food Intake and Weight Gain Associated with Olanzapine Administration in Rats

Objective

Lurasidone is an antipsychotic drug that shows a relative lack of weight gain common to many antipsychotics. Aripiprazole and ziprasidone also show little weight gain and can reduce olanzapine-induced food intake and weight gain in animals, paralleling some clinical findings. We hypothesized that lurasidone would have similar actions.

Methods

Female Lister-hooded rats received intraperitoneal injection either 2× vehicle (saline), lurasidone (3 mg/kg) and vehicle, olanzapine (1 mg/kg) and vehicle, or olanzapine and lurasidone. Following drug administration food intake was measured for 60min. A further series of rats underwent a seven-day regime of once-daily administration of the above doses and free access to food and water. Weight gain over the course of the study was monitored.

Results

Olanzapine induced a significant increase in food intake while lurasidone showed no significant effect. Co-administration of lurasidone with olanzapine suppressed the increase in food intake. Repeated dosing showed an increase in body weight after seven days with olanzapine, and no significant effect observed with lurasidone, while repeated administration of lurasidone with olanzapine reduced the effect of olanzapine on the increase in body weight.

Conclusion

These findings support our hypotheses in that lurasidone, in addition to a lack of effect on acute food intake and short term weight gain, can reduce olanzapine-induced food intake and weight gain in rats. This indicates the drug to have an active anti-hyperphagic mechanism, rather than solely the absence of a drug-induced weight gain that is such a severe limitation of drugs such as olanzapine.

Neuromyelitis optica spectrum disorder in three generations of a Chinese family

Neuromyelitis optica spectrum disorder is an inflammatory demyelinating disease that is largely sporadic. Familial disease has been reported in one or two generations, although its basis remains unknown. We report here three subjects meeting diagnostic criteria for NMOSD in one family: a father and son, and the maternal aunt of the father. Anticipation, of 27 years, was apparent in transmission from father to son. Aquaporin-4 antibodies were observed in the aunt but not the father and son, nor in other family members. A putative pathogenic mutation in the NECL2 gene was not found in this pedigree. This first report of NMOSD in three generations of one family underlines the heterogeneity of familial NMOSD.

GRIN2B promoter methylation deficits in early-onset schizophrenia and its association with cognitive function

Aim: We investigated GRIN1 and GRIN2B promoter methylation in first-episode schizophrenia patients compared with siblings and controls, testing for correlations between DNA methylation, cognitive performance and clinical variables. Materials & methods: Blood-derived DNA from all groups underwent bisulfite conversion and pyrosequencing to determine methylation at CpG sites within the GRIN1 and GRIN2B promoters and results were compared with the measure of global methylation LINE-1.Results: We found hypomethylation among all CpGs analyzed within GRIN2B promoter in patients and greater LINE-1 methylation in patients and siblings. CpG4 was correlated to a measure of intellectual function. Conclusion: Changes in GRIN2B promoter methylation may represent an environmental influence contributing to glutamatergic dysfunction in psychosis and relate to lower cognitive performance in subjects with first-episode schizophrenia.

Parvalbumin Promoter Methylation Altered in Major Depressive Disorder

Aims: To determine the extent of DNA methylation of parvalbumin gene (PVALB) promoter in major depressive disorder (MDD) patients with and without suicide attempt in comparison with healthy controls. Methods: The extracted DNA from dried blood spots of MDD patients (n = 92) including non-suicidal MDD and suicidal-MDD subgroups (n = 45 and n = 47, respectively) and age-matched control subjects (n = 95) was used for DNA methylation analysis at four CpG sites in the promoter sequence of PVALB by pyrosequencing. Results: The PVALB methylation was significantly increased at CpG2 and decreased at CpG4 in the MDD group compared to the control group, while there was no difference between non-suicidal MDD and suicidal-MDD subgroups. A significant inverse correlation of severity of MDD was indicated only for CpG4. Conclusion: This study provides the first evidence of abnormalities of PVALB promoter methylation in MDD and its correlation with MDD severity indicating a role for epigenetics in this psychiatric disorder.

Association study of the functional Catechol-O-Methyltranferase (COMT) Val158Met polymorphism on executive cognitive function in a Thai sample

Catechol-O-Methyltranferase (COMT) plays a crucial role in the removal of cortical dopamine and is strongly implicated in human executive function. Numerous studies have reported associations of the COMT Val158Met (rs4680) polymorphism with executive function in healthy subjects. However, little work has investigated this in the Thai population and the relationship of age and education with this association remains unclear. Therefore, this study was designed to investigate the association of this polymorphism of the COMT gene with executive cognitive brain function in healthy subjects and the relationship with age and education. The Wisconsin Card Sorting Test (WCST) was performed to assess executive function in 254 healthy Thai subjects (aged 20-72 years). The results showed a significant association of rs4680 with executive function, in which Val/Met heterozygotes demonstrated better cognitive set shifting performance. Moreover, Met allele carriers showed a significantly stronger effect in the categories completed score than did Val homozygotes. Furthermore, age and education also showed a significant association with COMT genotype and WCST. These results revealed that executive cognitive function is associated with COMT genotype and influenced by age and/or education level in a Thai sample.

Parvalbumin promoter hypermethylation in postmortem brain in schizophrenia

Deficits of brain parvalbumin (PV) are a consistent finding in schizophrenia and models of psychosis. We investigated whether this is associated with abnormal PV gene (PVALB) methylation in the brain in schizophrenia. Bisulfite pyrosequencing was used to determine cytosine (CpG) methylation in a PVALB promoter sequence. Greater PVALB methylation was found in schizophrenia hippocampus, while no differences were observed in prefrontal cortex. LINE-1 methylation, a measure of global methylation, was also elevated in both regions in schizophrenia, although the PVALB change was independent of this effect. These results provide the first evidence that PVALB promoter methylation is abnormal in schizophrenia and suggest that this epigenetic finding may relate to the reduction of PV expression seen in the disease.

Genetic variation of GRIA3 gene is associated with vulnerability to methamphetamine dependence and its associated psychosis

Methamphetamine (METH) is an addictive psychostimulant drug commonly leading to schizophrenia-like psychotic symptoms. Disturbances in glutamatergic neurotransmission have been proposed as neurobiological mechanisms and the α-amino-3 hydroxy-5 methyl-4 isoxazole propionic acid (AMPA) glutamate receptor has been implicated in these processes. Moreover, genetic variants in GRIAs, genes encoding AMPA receptor subunits, have been observed in association with both drug dependence and psychosis. We hypothesized that variation of GRIA genes may be associated with METH dependence and METH-induced psychosis. Genotyping of GRIA1 rs1428920, GRIA2 rs3813296, GRIA3 rs3761554, rs502434 and rs989638 was performed in 102 male Thai controls and 100 METH-dependent subjects (53 with METH-dependent psychosis). We observed no evidence of association with METH dependence and METH-dependent psychosis in the GRIA1 and GRIA2 polymorphisms, nor with single polymorphisms rs3761554 and rs989638 in GRIA3. An association of GRIA3 rs502434 was identified with both METH dependence and METH-dependent psychosis, although this did not withstand correction for multiple testing. Combining the analysis of this site with the previously-demonstrated association with BDNF rs6265 resulted in a highly significant effect. These preliminary findings indicate that genetic variability in GRIA3 may interact with a functional BDNF polymorphism to provide a strong risk factor for the development of METH dependence in the Thai population.

Tranylcypromine Isomers and Parkinson's Disease: New Aspects of an Old Drug

The tranylcypromine stereoisomers have been investigated in a series of comparative trials in Parkinson's disease and the results indicate that doses below 3 mg/day, of the (+)-isomer in particular, are effective as adjuvant antiparkinsonian therapy. Biochemical results, monitoring platelet monoamine oxidase (MAO) activity and plasma concentrations of drugs and phenylethylamine, an MAO substrate, showed such low doses of the (+)-isomer to inhibit MAO without inducing the hypertensive reaction sometimes observed at higher dosage. These findings, along with the observation of substantial pharmacokinetic differences between the two isomers are discussed, particularly in relation to reports on their efficacy in depressive illness.

Mechanisms underlying metabolic disturbances associated with psychosis and antipsychotic drug treatment

The increase in cardiovascular disease and reduced life expectancy in schizophrenia likely relate to an increased prevalence of metabolic disturbances. Such metabolic risk factors in schizophrenia may result from both symptom-related effects and aetiological factors. However, a major contributory factor is that of treatment with antipsychotic drugs. These drugs differ in effects on body weight; the underlying mechanisms are not fully understood and may vary between drugs, but may include actions at receptors associated with the hypothalamic control of food intake. Evidence supports 5-hydroxytryptamine receptor 2C and dopamine D2 receptor antagonism as well as antagonism at histamine H1 and muscarinic M3 receptors. These M3 receptors may also mediate the effects of some drugs on glucose regulation. Several antipsychotics showing little propensity for weight gain, such as aripiprazole, have protective pharmacological mechanisms, rather than just the absence of a hyperphagic effect. In addition to drug differences, there is large individual variation in antipsychotic drug-induced weight gain. This pharmacogenetic association reflects genetic variation in several drug targets, including the 5-hydroxytryptamine receptor 2C, as well as genes involved in obesity and metabolic disturbances. Thus predictive genetic testing for drug-induced weight gain would represents a first step towards personalised medicine addressing this severe and problematic iatrogenic disease.

Increased DNA methylation in the parvalbumin gene promoter is associated with methamphetamine dependence

Aim: The parvalbumin (PV)-containing subgroup of GABAergic neurons is particularly affected in schizophrenia and animal models of psychosis, including after methamphetamine (METH) administration. We investigated whether METH dependence and METH-induced psychosis may involve an effect on DNA methylation of the PVALB promoter. Materials & methods: The methylation of a PVALB promoter sequence was determined in 100 METH-dependent and 102 control subjects using pyrosequencing. Results: A significant increase in PVALB methylation was observed in METH dependence and METH-induced psychosis. No significant effect on long interspersed nucleotide element-1 methylation, a measure of global DNA methylation, was observed. Conclusion: These results demonstrate a specific association between elevated PVALB methylation and METH-induced psychosis. This finding may contribute to the GABAergic deficits associated with METH dependence.

DAT1 methylation is associated with methylphenidate response on oppositional and hyperactive-impulsive symptoms in children and adolescents with ADHD

OBJECTIVES

To examine the association of the DNA methylation of DAT1 and DRD4 gene with methylphenidate (MPH) response in attention deficit hyperactivity disorder (ADHD).

METHODS

One hundred and eleven DSM-IV defined ADHD Chinese Han children were recruited. Inattention, hyperactivity-impulsivity and oppositional symptoms were evaluated by the Swanson, Nolan and Pelham-IV-parent rating scale (SNAP-IV-P) at baseline and 6 weeks after MPH treatment. DNA methylation of CpG sites in the promoter sequences of DAT1 and DRD4 was examined for association with treatment response.

RESULTS

Greater improvement on the SNAP-IV-P total score and percentage change from baseline score were both significantly correlated with DAT1 methylation (rho =-0.222, P = .019 and rho = -0.203, P = .032, respectively). A secondary analysis demonstrated that the effect of DAT1 methylation on symptom response was primarily related to the percentage change in oppositional symptoms (rho = -0.242; P = .012), with a smaller significant effect on hyperactivity-impulsivity (rho = -0.192; P = .045). No significant correlation was found between the treatment effect on inattention and DAT1 methylation (rho = -0.101; P = .292). No significant correlation was observed between mean DRD4 methylation and measures of treatment outcome or baseline symptoms.

CONCLUSIONS

Our findings provide initial evidence for the involvement of the epigenetic alterations of DAT1 in modulating the response to MPH treatment in ADHD, primarily on oppositional and hyperactive-impulsive symptoms.

Atypical antipsychotics: recent research findings and applications to clinical practice: Proceedings of a symposium presented at the 29th Annual European College of Neuropsychopharmacology Congress, 19 September 2016, Vienna, Austria

Available evidence suggests that second-generation atypical antipsychotics are broadly similar to first-generation agents in terms of their efficacy, but may have a more favourable tolerability profile, primarily by being less likely to cause extrapyramidal symptoms. However, atypical antipsychotics are variably associated with disturbances in the cardiometabolic arena, including increased body weight and the development of metabolic syndrome, which may reflect differences in their receptor binding profiles. Effective management of schizophrenia must ensure that the physical health of patients is addressed together with their mental health. This should therefore involve consideration of the specific tolerability profiles of available agents and individualization of treatment to minimize the likelihood of adverse metabolic sequelae, thereby improving long-term adherence and optimizing overall treatment outcomes. Alongside this, modifiable risk factors (such as exercise, diet, obesity/body weight and smoking status) must be addressed, in order to optimize patients' overall health and quality of life (QoL). In addition to antipsychotic-induced side effects, the clinical management of early nonresponders and psychopharmacological approaches for patients with treatment-resistant schizophrenia remain important unmet needs. Evidence suggests that antipsychotic response starts early in the course of treatment and that early nonresponse accurately predicts nonresponse over the longer term. Early nonresponse therefore represents an important modifiable risk factor for poor efficacy and effectiveness outcomes, since switching or augmenting antipsychotic treatment in patients showing early nonresponse has been shown to improve the likelihood of subsequent treatment outcomes. Recent evidence has also demonstrated that patients showing early nonresponse to treatment with lurasidone at 2 weeks may benefit from an increase in dose at this timepoint without compromising tolerability/safety. However, further research is required to determine whether these findings are generalizable to other antipsychotic agents.

Association of polymorphisms in GAD1 and GAD2 genes with methamphetamine dependence

AIM

Association between polymorphisms in GAD genes and methamphetamine (METH) dependence was investigated in the Thai population.

MATERIALS & METHODS

Genotypes of rs769404 and rs701492 in GAD1 and rs2236418 in GAD2 polymorphisms were determined in 100 METH-dependent male subjects and 102 matched controls.

RESULTS

The genotype and allele frequencies of rs2236418 (GAD2) were associated with METH dependence and METH with psychosis, in which the G allele was related to increased risk. The presence of the rs769404-rs701492 (GAD1) C-C haplotype was associated with METH psychosis.

CONCLUSION

This study indicates that genetic variability in GAD1 and GAD2 contributes to risk of METH dependence and METH psychosis in the Thai population and indicates the role of the GABAergic system in these disorders.

Association of brain-derived neurotrophic factor valine to methionine polymorphism with sexual dysfunction following selective serotonin reuptake inhibitor treatment in female patients with major depressive disorder

INTRODUCTION

The occurrence of female sexual dysfunction (FSD) in patients with major depressive disorder (MDD) receiving selective serotonin reuptake inhibitors (SSRIs) treatment gives negative impacts on patients' quality of life and causes treatment discontinuation. We aimed to investigate whether genetic polymorphism of identified candidate gene is associated with FSD in our study population.

METHODS

This is a cross-sectional study. A total of 95 female patients with MDD who met the criteria of the study were recruited and were specifically assessed on the sexual function by trained psychiatrists. Patients' DNA was genotyped for BDNF Val66Met polymorphism using real-time polymerase chain reaction.

RESULTS

The prevalence of FSD in this study is 31.6%. In the FSD group, patients with problematic marriage were significantly more frequent compared with patients who did not have problematic marriage (P = 0.009). Significant association was detected in the lubrication domain with BDNF Val66Met polymorphism (P = 0.030) using additive genetic model, with even stronger association when using the recessive model (P = 0.013).

DISCUSSION

This study suggested that there was no significant association between BDNF Val66Met with FSD. However, this polymorphism is significantly associated with lubrication disorder in patients treated with SSRIs.

Modelling the cognitive and neuropathological features of schizophrenia with phencyclidine

Here, Reynolds and Neill describe the studies that preceded and followed publication of this paper, which reported a deficit in parvalbumin (PV), a calcium-binding protein found in GABA interneurons known to be reduced in schizophrenia patients, in conjunction with a deficit in reversal learning in an animal model for schizophrenia. This publication resulted from common research interests: Reynolds in the neurotransmitter pathology of schizophrenia, and Neill in developing animal models for schizophrenia symptomatology. The animal model, using a sub-chronic dosing regimen (sc) with the non-competitive NMDA receptor antagonist PCP (phencyclidine), evolved from previous work in rats (for PCP) and primates (for cognition). The hypothesis of a PV deficit came from emerging evidence for a GABAergic dysfunction in schizophrenia, in particular a deficit in PV-containing GABA interneurons. Since this original publication, a PV deficit has been identified in other animal models for schizophrenia, and the PV field has expanded considerably. This includes mechanistic work attempting to identify the link between oxidative stress and GABAergic dysfunction using this scPCP model, and assessment of the potential of the PV neuron as a target for new antipsychotic drugs. The latter has included development of a molecule targeting KV3.1 channels located on PV-containing GABA interneurons which can restore both PV expression and cognitive deficits in the scPCP model.

Subchronic administration of phencyclidine produces hypermethylation in the parvalbumin gene promoter in rat brain

AIM

A deficit in parvalbumin neurons is found in schizophrenia and several animal models of the disease. In this preliminary study, we determined whether one such model, phencyclidine (PCP) administration, results in changes in DNA methylation in the rat Pvalb promoter.

MATERIALS & METHODS

DNA from hippocampus and prefrontal cortex from rats, which 6 weeks previously received either 2 mg/kg PCP or vehicle for 7 days, underwent bisulphite pyrosequencing to determine methylation.

RESULTS

PCP administration induced significantly greater methylation at one of two Pvalb CpG sites in both prefrontal cortex and hippocampus, while no significant difference was found in long interspersed nucleotide element-1, a global measure of DNA methylation.

CONCLUSION

Subchronic PCP administration results in a specific hypermethylation in the Pvalb promoter which may contribute to parvalbumin deficits in this animal model of psychosis.

TPH-2 Polymorphisms Interact with Early Life Stress to Influence Response to Treatment with Antidepressant Drugs

BACKGROUND

Variation in genes implicated in monoamine neurotransmission may interact with environmental factors to influence antidepressant response. We aimed to determine how a range of single nucleotide polymorphisms in monoaminergic genes influence this response to treatment and how they interact with childhood trauma and recent life stress in a Chinese sample. An initial study of monoaminergic coding region single nucleotide polymorphisms identified significant associations of TPH2 and HTR1B single nucleotide polymorphisms with treatment response that showed interactions with childhood and recent life stress, respectively (Xu et al., 2012).

METHODS

A total of 47 further single nucleotide polymorphisms in 17 candidate monoaminergic genes were genotyped in 281 Chinese Han patients with major depressive disorder. Response to 6 weeks' antidepressant treatment was determined by change in the 17-item Hamilton Depression Rating Scale score, and previous stressful events were evaluated by the Life Events Scale and Childhood Trauma Questionnaire-Short Form.

RESULTS

Three TPH2 single nucleotide polymorphisms (rs11178998, rs7963717, and rs2171363) were significantly associated with antidepressant response in this Chinese sample, as was a haplotype in TPH2 (rs2171363 and rs1487278). One of these, rs2171363, showed a significant interaction with childhood adversity in its association with antidepressant response.

CONCLUSIONS

These findings provide further evidence that variation in TPH2 is associated with antidepressant response and may also interact with childhood trauma to influence outcome of antidepressant treatment.

BAP guidelines on the management of weight gain, metabolic disturbances and cardiovascular risk associated with psychosis and antipsychotic drug treatment

Excess deaths from cardiovascular disease are a major contributor to the significant reduction in life expectancy experienced by people with schizophrenia. Important risk factors in this are smoking, alcohol misuse, excessive weight gain and diabetes. Weight gain also reinforces service users' negative views of themselves and is a factor in poor adherence with treatment. Monitoring of relevant physical health risk factors is frequently inadequate, as is provision of interventions to modify these. These guidelines review issues surrounding monitoring of physical health risk factors and make recommendations about an appropriate approach. Overweight and obesity, partly driven by antipsychotic drug treatment, are important factors contributing to the development of diabetes and cardiovascular disease in people with schizophrenia. There have been clinical trials of many interventions for people experiencing weight gain when taking antipsychotic medications but there is a lack of clear consensus regarding which may be appropriate in usual clinical practice. These guidelines review these trials and make recommendations regarding appropriate interventions. Interventions for smoking and alcohol misuse are reviewed, but more briefly as these are similar to those recommended for the general population. The management of impaired fasting glycaemia and impaired glucose tolerance ('pre-diabetes'), diabetes and other cardiovascular risks, such as dyslipidaemia, are also reviewed with respect to other currently available guidelines.These guidelines were compiled following a consensus meeting of experts involved in various aspects of these problems. They reviewed key areas of evidence and their clinical implications. Wider issues relating to primary care/secondary care interfaces are discussed but cannot be resolved within guidelines such as these.

Does elevated peripheral benzodiazepine receptor gene expression relate to cognitive deficits in methamphetamine dependence?

BACKGROUND

Methamphetamine (METH) is a neurotoxin and psychostimulant drug with potent effects on the central nervous system. With chronic METH administration, an inflammatory glial response is observed as a result of METH-induced neurotoxicity. One inflammatory marker is the peripheral benzodiazepine receptor (PBR).

OBJECTIVE

The purpose of the present study was to determine whether PBR expression is changed in METH dependence and whether the changes relate to cognitive deficits.

METHODS

Reverse transcriptase-polymerase chain reaction was used to investigate PBR gene expression in blood samples taken from 14 male subjects with METH dependence and 14 controls.

RESULTS

The results showed a significant increase in PBR gene expression in METH dependence, suggestive of a systemic inflammatory response. The increase remained elevated for more than 1 year following abstinence from METH use, but eventually returned to normal. Subjects with elevated PBR also exhibited a deficit in one domain of the Wisconsin Card Sorting Test.

CONCLUSION

The results suggest that systemic inflammatory effects can be associated with chronic METH abuse, and this may relate to the cognitive deficits seen in METH dependence. Copyright © 2016 John Wiley & Sons, Ltd.

Concurrent Risperidone Administration Attenuates the Development of Locomotor Sensitization Following Sub-Chronic Phencyclidine in Rats

INTRODUCTION

In schizophrenia early treatment may prevent disorder onset, or at least minimize its impact, suggesting possible neuroprotective properties of antipsychotics. The present study investigates the effects of chronic treatment with the atypical antipsychotic, risperidone, on locomotor sensitization in the subchronic phencyclidine-treated rat.

METHODS

Rats were treated with phencyclidine sub-chronically (2 mg/kg bi-daily for one week followed by a one-week wash-out period) or vehicle. Half of the phencyclidine group was concurrently treated with risperidone (0.5 mg/kg IP) twice daily for 15 days, beginning 3 days before the start of phencyclidine administration. 6 weeks after treatment all rats were injected with a phencyclidine-challenge (3.2 mg/kg) and immediately after their locomotor activity measured for 20 min.

RESULTS

Co-administration of risperidone at the time of phencyclidine administration significantly reduced the phencyclidine-challenge locomotor effect administered 6 weeks later.

DISCUSSION

These results demonstrate that concurrent risperidone is neuroprotective, and clearly suggests its functionality can be translated to a clinical setting for treating the so-called prodrome.

BDNF (Val66Met) genetic polymorphism is associated with vulnerability for methamphetamine dependence

AIM

Association of the brain-derived neurotrophic factor (BDNF) genetic polymorphism rs6265 (Val66Met) with methamphetamine (METH) dependence and METH-induced psychosis was investigated in the Thai population.

MATERIALS & METHODS

The rs6265 genotype was determined in 100 male METH-dependent subjects and 102 controls using a real-time PCR high-resolution melt (RT-PCR-HRM) assay.

RESULTS

The rs6265 genotype demonstrated significant differences in distribution between METH-dependent subjects and controls in which the frequency of GG genotype versus A-allele carriers was associated with METH dependence. Moreover, a significant effect of genotype on the occurrence of psychosis was found, with a lower frequency of GG genotype associated with METH-induced psychosis.

CONCLUSION

The present findings indicate that rs6265 is associated with METH dependence in the Thai population, with the GG genotype greater in METH-dependent subjects but reducing the emergence of METH-dependent psychosis.

Polymorphisms of serotonin neurotransmission and their effects on antipsychotic drug action

The receptor pharmacology of many antipsychotic drugs includes actions at various serotonin (5-hydroxytryptamine [5-HT]) receptors. The 5-HT neurotransmitter system is thought to be involved in many of the consequences of treatment with antipsychotic drugs, including both symptom response, primarily of negative and depressive symptoms, and adverse effects, notably extrapyramidal side effects and weight gain. There is substantial interindividual variability in these drug effects, to which genetic variability contributes. We review here the influence of functional polymorphisms in genes associated with 5-HT function, including the various processes of neurotransmitter synthesis, receptors, transporters and metabolism, on the clinical response to, and adverse effects of, antipsychotic drugs. The relatively young field of epigenetics also contributes to the variability of 5-HT-related genes in influencing drug response. Several of these findings inform our understanding of the mechanisms of antipsychotic drug action, and also provide the opportunity for the development of genetic testing for personalized medicine.

Association of FTO, LEPR and MTHFR gene polymorphisms with metabolic syndrome in schizophrenia patients receiving antipsychotics

AIM

The occurrence of metabolic syndrome (MS) in schizophrenia patients receiving long-term antipsychotics (APs) contributes to their high mortality rate. We aimed to determine whether genetic polymorphisms of identified candidate genes are associated with MS in our study population.

MATERIALS & METHODS

We recruited 206 schizophrenia patients receiving AP treatment for at least a year. Cross-sectional measurements of weight, height, blood pressure, waist and hip circumference, and other lipid profiles were recorded. Patient DNA was genotyped for 16 candidate gene polymorphisms.

RESULTS

Of these patients, 59.7% were found to have MS while 40.3% did not. All metabolic parameters were significantly different between the two groups. Only three of the 16 polymorphisms studied showed significant association with MS; rs9939609 of the FTO gene confers risk for MS (odds ratio [OR]: 1.73, 95% CI: 1.07-2.78, p = 0.026), while rs1137101 of the LEPR gene (OR: 0.47, 95% CI: 0.28-0.80, p = 0.005) and rs1801133 of the MTHFR gene (OR: 0.59, 95% CI: 0.35-0.99, p = 0.049) are protective against MS.

CONCLUSION

Polymorphisms of the FTO, LEPR and MTHFR genes may play a role in MS in Malaysian schizophrenia patients receiving long-term treatment with APs.