Beyond the "hype" on the association between metabolic syndrome and atypical antipsychotics: the confounding effects of cohort, typical antipsychotics, severe mental illness, comedications, and comorbid substance use

The relationship between serum adiponectin levels, cardiometabolic indices and metabolic syndrome in schizophrenia

BACKGROUND

Adiponectin is a hormone secreted by adipose tissues that is thought to influence lipid and glucose metabolism, and the development of metabolic derangements, including metabolic syndrome (MetS), in schizophrenia. We aim to determine the serum adiponectin levels in Chinese patients with schizophrenia, and explore the relationship between adiponectin levels and metabolic parameters, including MetS and its components. We hypothesized that serum adiponectin levels are similar in schizophrenia patients and controls, but decreased amongst patients on atypical antipsychotics.

METHODS

81 patients and 81 controls were recruited. Anthropometric parameters and fasted blood samples for metabolic measurements were obtained. Serum adiponectin levels were measured using Bioplex assays.

RESULTS

There was no difference in median adiponectin levels between schizophrenia patients and controls. Those taking typical antipsychotics alone had lower median adiponectin levels than those on mixed typical and atypical antipsychotics. Serum adiponectin level, controlled for age, gender and body mass index, was positively correlated with high-density lipoprotein cholesterol, and negatively correlated with diastolic blood pressure, total cholesterol, low-density lipoprotein cholesterol, and triglyceride levels in schizophrenia patients. Patients with MetS had lower median adiponectin levels than those without MetS, and serum adiponectin levels decreased as the number of MetS components increased. After adjusting for variables thought to influence MetS, our logistic regression model did not reveal any significant association between adiponectin levels and MetS in schizophrenia patients.

CONCLUSION

Our findings highlight the need for more studies focusing on serum adiponectin level and its relationship with MetS in schizophrenia, particularly in those taking typical antipsychotics.

High risk of metabolic syndrome among black South African women with severe mental illness

Background

There is an increased prevalence of metabolic syndrome (MetS) in individuals with severe mental illness (SMI) globally. The prevalence of MetS is higher in black women compared to black men from South Africa.

Aim

To compare the prevalence of MetS between black South African men and women with SMI taking antipsychotic medication. Further, this prevalence was compared to the prevalence in a matched control group of black South African men and women without SMI.

Setting

A general hospital psychiatric unit.

Methods

A cross-sectional study was undertaken to compare the prevalence of MetS in a group of multi-ethnic participants with SMI treated with antipsychotic medication and a matched control group without SMI, applying the 2009 Joint Interim Statement (JIS) criteria. Here, we included only the black African participants to compare MetS prevalence between men and women.

Results

There were 232 participants in the group with SMI (male 155 and female 77) and without SMI (male 156 and female 76). The prevalence of MetS was more than three times higher in women with SMI compared to men with SMI (37.7% vs. 10.3%, p < 0.001). There was no significant difference in the prevalence of MetS in men or women between the groups with and without SMI. In multivariate logistic regression analysis, female gender (odds ratio [OR] 7.66), advancing age (OR 1.08) and longer duration of illness (OR = 1.15) were significant risk factors for MetS in SMI.

Conclusion

In black South Africans with SMI on antipsychotic medication, there is a higher prevalence and risk for MetS in women compared to men.

Evaluation of different approaches for confounding in nonrandomised observational data: a case-study of antipsychotics treatment

Although randomised controlled trials are regarded as the gold standard for treatments efficacy, evidence from observational studies remains relevant. To address the problem of possible confounding in these studies, investigators must employ analysis methods that adjust for confounders and lead to an unbiased estimation of the treatment effect. In this paper, the authors describe two relevant statistical methods. The first method represents the classical approach consisting of a multiple regression model including the effects of treatment and covariates. This approach considers the relation between prognostic factors and the outcome variable as a relevant criterion for adjustment. The second method is based on the propensity score, and focuses on the relation between prognostic factors and treatment assignment. These approaches were applied to a cohort of 183 French schizophrenic patients who were followed for a 2-year period (from 1998 to 2000). The probability of relapse according to antipsychotic treatment exposure was modelled using Cox regression models with the two statistical methods. Goodness-of-fit criteria were used to compare the modelling approaches. This study demonstrates that the propensity score, a predicted probability, has an important balancing property that underscores its value in strengthening the results of nonrandomised observational studies.

Using structural equations to test for a direct effect of some antipsychotics on triglyceride levels in drug-naïve first-episode psychosis patients

Some antipsychotics probably increase the risk of metabolic syndrome. Antipsychotics may differentially influence some elements of metabolic syndrome (obesity, hyperlipidemia, hyperglycemia or hypertension) through various pharmacological mechanisms. In a published study of all first psychotic episodes in a Spanish hospital's catchment area population in Cantabria (Spain), patients were randomly assigned to receive haloperidol (3-9 mg/day), olanzapine (5-20mg/day) or risperidone (3-6 mg/day). In this article, a structural-equation modeling approach tested the mechanistic hypothesis that olanzapine directly (without the mediation of weight gain) increases triglyceride levels, whereas risperidone and haloperidol do not have these effects. A structural equation model was built using the 110 patients whose assigned antipsychotic was not changed during the first 3 months of treatment, and who provided both triglyceride and body mass index (BMI) measurements at baseline and at the end of the 3rd month of treatment. A second structural equation included 72 patients whose antipsychotic was not changed during the first year. After 3 months and controlling for confounders, olanzapine patients had triglyceride levels that were 29.2mg/dL higher [95% confidence interval, (10.9, 47.5)] than those of risperidone patients with comparable baseline triglyceride levels. After 12 months, they were 63.1mg/dL higher (18.6, 107.6) than those of patients with a comparable history of triglyceride values during the first 3 months. Haloperidol effects on triglyceride levels and BMI were no different from those of risperidone. In conclusion, olanzapine increased triglyceride levels without the mediation of weight gain during a one-year study in naïve patients.

Cardiovascular risk in a first-episode psychosis sample: a 'critical period' for prevention?

OBJECTIVE

Studies in first episode psychosis samples about status of cardiovascular risk factors have shown discordant results. We aimed to determine the 10-year risk of developing coronary heart disease in a sample of first episode psychosis patients referred to an early intervention clinic and compared the same with age, gender, and race matched controls from the U.S. National Health and Nutrition Examination Survey (NHANES).

METHOD

We conducted a cross-sectional analysis of baseline data of 56 subjects enrolled in first episode psychosis clinic from April 2006 to January 2010. This sample was compared with age, gender, and race matched 145 individuals drawn from NHANES 2005-2006 database. Sociodemographic and clinical variables were collected. Physical examination including laboratory evaluation was used to screen for common medical illnesses. The 10-year risk of developing coronary heart disease was calculated by using a tool developed by the National Cholesterol Education Program (NCEP-ATP III).

RESULTS

There were elevated rates of smoking (46%) and hypertension (11%) albeit statistically significant differences from the control could not be demonstrated for these measures or weight, body mass index, or total or HDL cholesterol, fasting plasma glucose, status of diabetes and impaired fasting plasma glucose, HbA1C level. The 10-year median (range) risk of developing coronary heart disease in patients and controls was 1 (0-5)% and 0 (0-9)% respectively. The difference was not statistically significant.

CONCLUSIONS

First episode psychosis patients do not present with significantly higher cardiovascular risk than age and race-matched controls despite clinically significant prevalence of individual risk factors. This sample presents an opportunity for early intervention for the primary prevention of cardiovascular morbidity and mortality.

The metabolic syndrome and its constituting variables in atypical antipsychotic-treated subjects: comparison with other drug treatments, drug-free psychiatric patients, first-degree relatives and the general population in Venezuela

BACKGROUND

Few studies on the association between atypical antipsychotic drug (AAP) administration and metabolic dysfunction have concurrently evaluated the general population (GP), other psychotropic drug treatments and drug-free psychiatric patients.

METHODS

We assessed the frequency of the metabolic syndrome (MS) according to the National Cholesterol Education Program criteria (NCEP) and its constituting variables in a GP sample (n=271) and in patients receiving, for at least three consecutive months, antiepileptic drugs (n=93), olanzapine (n=162), clozapine (n=105), typical antipsychotics (n=117), other AAP (n=58), other psychotropic drugs (n=185), and drug-free individuals (n=636). Subjects were clinically classified as schizophrenia, bipolar or other axis I disorders (DSM-IV-RT), and as first-degree relatives of each diagnostic group.

RESULTS

The MS was detected in 26.6% of the GP (95% confidence interval: 21.5-31.8). No diagnostic or treatment group had a significantly higher age-adjusted frequency than the GP (p>0.05). Treatment duration did not significantly affect the results. However, significant differences were observed in the frequency of abnormal MS constituting variables in comparison to the GP. For example, schizophrenia patients and their relatives, bipolar subjects and olanzapine- and clozapine-treated patients had higher abnormal waist circumference values. In addition, bipolar patients and their relatives and subjects treated with olanzapine and other AAPs had higher frequencies of abnormal glucose levels. Neither schizophrenia nor bipolar patients in the diagnostic categories nor the olanzapine or the clozapine groups displayed higher proportions of abnormal triglycerides, high density cholesterol or blood pressure levels than the GP.

CONCLUSIONS

While we did not demonstrate an increased frequency of the MS in AAP-treated subjects, our results confirm that specific metabolic variables must be monitored in psychiatric patients. Besides they stress the importance, in epidemiological studies, of concurrently comparing the figures recorded in AAP-treated patients with those obtained in the local GP, other drug treatment groups and drug-free subjects when referring to the magnitude of the metabolic effects of specific antipsychotic agents.

Relapse according to antipsychotic treatment in schizophrenic patients: a propensity-adjusted analysis

OBJECTIVE

To compare the rate of relapse as a function of antipsychotic treatment (monotherapy vs. polypharmacy) in schizophrenic patients over a 2-year period.

METHODS

Using data from a multicenter cohort study conducted in France, we performed a propensity-adjusted analysis to examine the association between the rate of relapse over a 2-year period and antipsychotic treatment (monotherapy vs. polypharmacy).

RESULTS

Our sample consisted in 183 patients; 50 patients (27.3%) had at least one period of relapse and 133 had no relapse (72.7%). Thirty-eight (37.7) percent of the patients received polypharmacy. The most severely ill patients were given polypharmacy: the age at onset of illness was lower in the polypharmacy group (p = 0.03). Patients that received polypharmacy also presented a higher general psychopathology PANSS subscore (p = 0.04) but no statistically significant difference was found in the PANSS total score or the PANSS positive or negative subscales. These patients were more likely to be given prescriptions for sedative drugs (p < 0.01) and antidepressant medications (p = 0.03). Relapse was found in 23.7% of patients given monotherapy and 33.3% given polypharmacy (p = 0.16). After stratification according to quintiles of the propensity score, which eliminated all significant differences for baseline characteristics, antipsychotic polypharmacy was not statistically associated with an increase of relapse: HR = 1.686 (0.812; 2.505).

CONCLUSION

After propensity score adjustment, antipsychotic polypharmacy is not statistically associated to an increase of relapse. Future randomised studies are needed to assess the impact of antipsychotic polypharmacy in schizophrenia.

The role of valproate in metabolic disturbances in bipolar disorder patients

BACKGROUND

Our previous report showed that patients with bipolar disorder (BD) have higher prevalence of hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL) and obesity in Taiwan. To confirm whether the metabolic disturbances is associated with the disease itself or the medications used for treating BD, we further compared the metabolic status among the valproate (VPA) treated BD patients, drug-free BD patients and healthy controls in Taiwan.

METHOD

This cross-sectional study included 119 healthy controls and 77 BD patients diagnosed according to the DSMIV-TR criteria in a university hospital. Among the diseased group, 25 remitted BD patients were drug-free (BD-F), and 52 of them were treated with VPA (BD-VPA). Their body mass index (BMI), plasma glucose levels and plasma lipid profiles were measured.

RESULTS

Plasma fasting glucose, insulin, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol (LDL) levels were significantly different among BD-VPA, the BD-F, and the healthy control groups. Valproate treatment was associated with significant higher plasma insulin, triglyceride, and BMI levels as well as lower fasting glucose and HDL levels. However, these biochemical indexes did not differ significantly between the BD-F and the healthy control groups.

CONCLUSION

These results provide further evidence that VPA treatment for BD may increase the risk of metabolic disturbances. The risk may be reduced after discontinuing VPA medication.

Do atypical antipsychotic drugs reduce the risk of ischemic heart disease and mortality? Possible role of 5-HT2A receptor blockade

A recent Finnish study reported that long-term cumulative exposure to any antipsychotic treatment was related to lower mortality than was no drug exposure. We hypothesize that the antipsychotic 5-HT2A receptor blockade might protect from ischemic heart disease and buffer the deleterious metabolic effects of antipsychotics. The 5-HT2A receptor may be involved in vascular smooth muscle contraction, coronary artery spasms, platelet aggregation and thrombus formation. 5-HT2A receptor blockade might protect from ischemic heart disease by decreasing platelet aggregation and myocardium hypertrophy. Long-term follow-up studies are needed to clearly establish the long-term contribution of the various antipsychotic drugs to ischemic heart disease, and to explore our hypothesis that 5-HT2A receptor blockade may be protective for cardiovascular disease.

QTc interval in a sample of long-term schizophrenia inpatients

This naturalistic study attempted to determine the prevalence of prolonged QTc interval in a relatively large population of inpatients hospitalized with chronic schizophrenia, and to explore QTc relationship with demographic variables, metabolic parameters and prescribed treatments. All inpatients from a Spanish long-term psychiatric hospital were cross-sectionally investigated to determine the prevalence of QTc prolongation and metabolic syndrome. The sample with a DSM-IV diagnosis of schizophrenia included 171 Caucasian inpatients, all of Spanish origin. A prolonged QTc interval was defined as >450 ms in men and >470 ms in women. The relationships between QTc and other continuous variables were assessed using a linear regression model with QTc as the dependent variable. Only 10 patients (6%) had a prolonged QTc interval; one case was possibly explained by hypokalemia. Three patients (2%) had a QTc > 500 ms. Gender, old age (> or = 50 years old), current smoking, systolic blood pressure, HDL cholesterol and history of arrhythmia were found to have significant effects on QTc interval in a linear regression analysis. After controlling for significant variables, the mean QTc interval was not significantly influenced by antipsychotic dose, type of antipsychotic treatment, the use of depot antipsychotics, or the number of different antipsychotics prescribed. Our study focused on long-term schizophrenia inpatients with frequent antipsychotic polypharmacy and high antipsychotic doses, and suggested that after excluding the case with hypokalemia length of QTc was associated with history of arrhythmias and with metabolic factors, while the effects of antipsychotic compound or class were not so evident.

Acetyl-coenzyme A carboxylase alpha gene variations may be associated with the direct effects of some antipsychotics on triglyceride levels

Acetyl-coenzyme A carboxylase alpha (ACACA) single-nucleotide polymorphism (SNP) (rs2229416) was significantly associated with hypertriglyceridemia, during exploration of antipsychotic direct effects on lipids. Neuropeptide Y (NPY) gene (rs1468271) and ACACB gene (rs2241220) SNPs were significantly associated with severe hypercholesterolemia. In the same sample (173 patients on olanzapine, quetiapine, chlorpromazine or mirtazapine [increasing the risk of hyperlipidemia] and 184 controls taking other antipsychotics), three (rs1266175, rs12453407 and rs9906543) of eight additional ACACA SNPs were significantly associated with hypertriglyceridemia in those taking drugs of interest, but not in controls. Five other ACACA SNPs, three additional NPY SNPs, and seven additional ACACB SNPs were not significant.

Influence of antipsychotics on mortality in schizophrenia: systematic review

BACKGROUND

Antipsychotic medication is the cornerstone of schizophrenia treatment. The impact of long-term exposure to antipsychotics on life-expectancy has recently received some attention, partly because awareness is increasing of the differential mortality of people with schizophrenia and the general population.

METHODS

A systematic review of studies assessing the association between antipsychotic exposure and mortality in persons with schizophrenia was undertaken.

RESULTS

In total, 12 studies met the inclusion criteria. Three out of five studies examining antipsychotic dosage and higher mortality showed a significant association for one or more antipsychotics. Two out of four found negative effects of antipsychotic polypharmacy on life-expectancy. Some studies found a lower cardiovascular mortality risk with higher treatment intensity or when comparing current versus past or non-use of antipsychotics. Others established a stable correlation between antipsychotic exposure and an increase in cardiovascular mortality. Evidence for differential effects on mortality in favor of second generation (SGA) compared to first generation antipsychotics was inconsistent. No study of SGA drugs had a sufficient follow-up time. A major confounding factor may be a higher risk factor load for somatic disorders in the most severely mentally ill.

CONCLUSION

There is some evidence that long-term exposure to antipsychotics increases mortality in schizophrenia. More rigorously designed, prospective studies are urgently needed.

Personalized medicine: boon or budget-buster?

While the development of personalized or molecular medicine is a laudable goal, there remain multiple barriers to its implementation. For example, little is known about the functions of noncoding regions of DNA, as well as the interplay of drug response, environmental factors, and the patient's genetic profile. In addition, there is a constant influx of new information on genetic factors such as epigenetic variation that could further complicate the development of medications based on the genetic profile, as well as the cost of profiling. However, assuming that clinically relevant genetic factors will be discovered and that drugs can be developed based on the molecular changes induced by those genetic factors, I suggest that the costs involved may substantially exceed the savings brought about by abandoning our current "one drug fits all" approach. While there is no doubt that our current approach is inefficient and expensive, remarkably little attention has been paid to the potential costs of molecular medicine. Given the current economic crisis, the time is ripe for a debate on this issue.

Practical guidelines for the use of new generation antipsychotic drugs (except clozapine) in adult individuals with intellectual disabilities

New generation antipsychotic (NGA) drugs introduced to the US market after clozapine (aripiprazole, olanzapine, paliperidone, quetiapine, risperidone, and ziprasidone) are frequently used in individuals with intellectual disabilities (ID). However, there is very limited research to fully establish evidence-based or personalized medicine approaches for their use in this population. These guidelines take a pragmatic approach to establishing frameworks for their use by utilizing the prescribing information and reviewing the available literature on other relevant neuropsychiatric disorders. In the absence of expert consensus guidance and well-controlled comparison trials, we present a set of guidelines to inform initiation, dosing and monitoring of use in adults. Further, in these guidelines we provide practical information on drug-drug interactions and adverse drug reactions, and a brief review of discontinuation syndromes, potential for abuse, use during pregnancy and cost considerations. We also provide drug utilization review forms for each NGA to facilitate implementation of these guidelines, these guidelines provide a practical and necessary resource for practitioners treating psychiatric disorders and challenging behaviors in adult individuals with ID.

HTR2C gene polymorphisms and the metabolic syndrome in patients with schizophrenia: a replication study

In a previous study, we found an association between 5-hydroxytryptamine (serotonin) receptor 2C (HTR2C) polymorphisms and the occurrence of the metabolic syndrome in patients using antipsychotics. In the current study, we set out to replicate our findings in another sample of patients and to explore in a pooled analysis of both samples the influence of the effect of individual antipsychotics. Data for this cross-sectional study came from 2 different samples, the original sample (n = 112) and the replication sample (n = 164). Primary end point was the prevalence of the metabolic syndrome as classified by a modified version of the National Cholesterol Education Program's Adult Treatment Panel III. Primary determinants were polymorphisms in the promoter region of the HTR2C gene [HTR2C:c.1-142948(GT)n, rs3813929 (-759 C/T), and rs518147 (-697 G/C)] and an intragenic polymorphism (rs1414334:C>G). The variants of HTR2C:c.1-142948(GT)n (odds ratio [OR], 1.69; 95% confidence interval [CI], 0.75-3.81) and rs1414334 (OR, 2.35; 95% CI, 0.96-5.77) were not significantly associated with the metabolic syndrome in the replication sample but did show significance in the pooled analysis (OR, 2.09; 95% CI, 1.12-3.91; and OR, 2.35; 95% CI, 1.19-4.62, respectively). The variant rs1414334 C allele was specifically associated with the metabolic syndrome in patients using clozapine (OR, 9.20; 95% CI, 1.95-43.45) or risperidone (OR, 5.35; 95% CI, 1.26-22.83). This study extends previous findings to a larger sample of patients and implicates specific antipsychotic drugs. The increased risk for the metabolic syndrome is particularly strong in carriers of the rs1414334 C allele using clozapine or risperidone.

DNA microarray technology in the clinical environment: the AmpliChip CYP450 test for CYP2D6 and CYP2C19 genotyping

INTRODUCTION

An important technological advance in genetic testing is the DNA microarray, which allows for the simultaneous testing of thousands of DNA sequences. The AmpliChip CYP450 Test employs this microarray technology for cytochrome P450 (CYP) 2D6 and CYP2C19 genotyping. Isoenzymes encoded by these genes are responsible for the metabolism of many widely prescribed drugs. The objectives of this study were to identify CYP2D6 and CYP2C19 alleles and phenotypes in a psychiatric patient population in Kentucky, and to describe practical issues associated with DNA microarray technology.

METHODS

A total of 4,532 psychiatric patients were recruited from three state hospitals in Kentucky. Whole blood, buccal swabs, or saliva samples were genotyped with the AmpliChip CYP450 Test to derive a predicted phenotype.

RESULTS

In this cohort, the overall prevalence of CYP2D6 poor metabolizers was 7.6% (95% CI 7%, 8.3%), 8.2% in the Caucasians (95% CI 7.4%, 9.%) and 1.8% in the African Americans (95% CI 0.9%, 3.5%). The overall prevalence of CYP2D6 ultrarapid metabolizers was 1.5% (95% CI 1.2%, 1.9%), 1.5% in the Caucasians (95% CI 1.1%, 1.9%) and 2.0% in the African Americans (95% CI 1.1%, 3.7%). The overall prevalence of CYP2C19 poor metabolizers was 2.0% (95% CI 1.8%, 2.7%), 2.2% in Caucasians (95% CI 1.6%, 2.5%) and 4.0% in African Americans (95% CI 2.6%, 6.1%).

CONCLUSION

We also propose a numeric system for expression of CYP2D6 and CYP2C19 enzyme activity to aid clinicians in determining treatment strategy for patients receiving therapeutics that are metabolized by the CYP2D6 or CYP2C19 gene products.