Insulin sensitivity, adjusted β-cell function and adiponectinaemia among lean drug-naive schizophrenic patients treated with atypical antipsychotic drugs: A nine-month prospective study

Metabolic effects of atypical antipsychotics: Molecular targets

Atypical antipsychotics (AAPs) are commonly prescribed drugs in the treatment of schizophrenia, bipolar disorder and other mental diseases with psychotic traits. Although the use of AAPs is associated with beneficial effects in these patients, they are also associated with undesired metabolic side effects, including metabolic syndrome (MetS). MeS is defined by the presence of metabolic abnormalities such as large waist circumference, dyslipidemia, fasting hyperglycemia and elevated blood pressure, which predispose to type 2 diabetes (T2D) and cardiovascular disease. In this review, the molecular and cellular mechanisms involved in these undesired metabolic abnormalities induced by AAPs are described. These mechanisms are complex as AAPs have multiple cellular targets which significantly affect the activities of several hormones and neuromodulators. Additionally, AAPs affect all the relevant metabolic organs, namely the liver, pancreas, adipose tissue, skeletal muscle and intestine, and the central and peripheral nervous system as well. A better understanding of the molecular targets linking AAPs with MetS and of the mechanisms responsible for clinically different side effects of distinct AAPs is needed. This knowledge will help in the development of novel AAPs with less adverse effects as well as of adjuvant therapies to patients receiving AAPs.

Clozapine suppresses NADPH oxidase activation, counteracts cytosolic H2O2, and triggers early onset mitochondrial dysfunction during adipogenesis of human liposarcoma SW872 cells

Long-term treatment of schizophrenia with clozapine (CLZ), an atypical antipsychotic drug, is associated with an increased incidence of metabolic disorders mediated by poorly understood mechanisms. We herein report that CLZ, while slowing down the morphological changes and lipid accumulation occurring during SW872 cell adipogenesis, also causes an early (day 3) inhibition of the expression/nuclear translocation of CAAT/enhancer-binding protein β and peroxisome proliferator-activated receptor γ. Under the same conditions, CLZ blunts NADPH oxidase-derived reactive oxygen species (ROS) by a dual mechanism involving enzyme inhibition and ROS scavenging. These effects were accompanied by hampered activation of the nuclear factor (erythroid-derived2)-like 2 (Nrf2)-dependent antioxidant responses compared to controls, and by an aggravated formation of mitochondrial superoxide. CLZ failed to exert ROS scavenging activities in the mitochondrial compartment but appeared to actively scavenge cytosolic H2O2 derived from mitochondrial superoxide. The early formation of mitochondrial ROS promoted by CLZ was also associated with signs of mitochondrial dysfunction. Some of the above findings were recapitulated using mouse embryonic fibroblasts. We conclude that the NADPH oxidase inhibitory and cytosolic ROS scavenging activities of CLZ slow down SW872 cell adipogenesis and suppress their Nrf2 activation, an event apparently connected with increased mitochondrial ROS formation, which is associated with insulin resistance and metabolic syndrome. Thus, the cellular events characterised herein may help to shed light on the more detailed molecular mechanisms explaining some of the adverse metabolic effects of CLZ.

Influence of antipsychotic medications on hyperlipidemia risk in patients with schizophrenia: evidence from a population-based cohort study and in vitro hepatic lipid homeostasis gene expression

Introduction

Schizophrenia increases the risk of mortality and cardiovascular disease (CVD) risk. However, the correlation between antipsychotics (APs) and CVD remains controversial. Hyperlipidemia is a significant risk factor for CVD.

Methods

We conducted a nationwide population-based retrospective cohort study to investigate the effects of APs on the risk of hyperlipidemia and lipid homeostasis gene expression. We used data from the Longitudinal Health Insurance Database of Taiwan on new-onset schizophrenia patients and a comparison cohort without schizophrenia. We used a Cox proportional hazards regression model to analyze the differences in hyperlipidemia development between the two cohorts. Furthermore, we examined the effects of APs on the hepatic expression of lipid homeostasis-related genes.

Results

After adjusting for potential interrelated confounding factors, the case group (N = 4,533) was found to have a higher hyperlipidemia risk than the control cohort (N = 4,533) [adjusted hazard ratio (aHR), 1.30, p < 0.001]. Patients with schizophrenia without APs had a significantly higher risk of hyperlipidemia (aHR, 2.16; p < 0.001). However, patients receiving APs had a significantly lower risk of hyperlipidemia than patients not receiving APs (all aHR ≤ 0.42, p < 0.001). First-generation antipsychotics (FGAs) induce the expression of hepatic lipid catabolism genes in an in vitro model.

Discussion

Patients with schizophrenia had a higher risk of hyperlipidemia than controls; however, compared with non-treated patients, AP users had a lower risk of hyperlipidemia. Early diagnosis and management of hyperlipidemia may help prevent CVD.

Psychiatric Comorbidities in Patients With Idiopathic Intracranial Hypertension: A Prospective Cohort Study

BACKGROUND AND OBJECTIVES

Psychiatric disease is a frequent comorbidity in idiopathic intracranial hypertension (IIH) and has been associated with a poor subjective outcome. No prospective studies have investigated psychiatric comorbidities in new-onset IIH. Our primary aim was to investigate disease severity in IIH depending on comorbid psychiatric disease. Important secondary outcomes were disease severity after 6 months and prevalence of psychiatric diseases in IIH.

METHODS

This prospective, observational cohort study consecutively included patients with clinically suspected, new-onset IIH from 2 headache centers. A standardized diagnostic workup was completed to confirm or exclude IIH according to the revised Friedman criteria: semi-structured interview, neurologic and neuro-ophthalmologic examination, lumbar puncture with opening pressure (OP), and neuroimaging. Exclusion criteria were known IIH, secondary intracranial hypertension, missing data, and pregnancy. Disease severity was evaluated based on papilledema, visual fields, OP, and headache in patients with IIH without psychiatric disease (IIH-P) compared with patients with IIH with psychiatric disease (IIH+P). A blinded neuro-ophthalmologist assessed visual outcomes. Age- and sex-matched prevalence rates of psychiatric diseases in the general population were found in national reports.

RESULTS

A total of 258 patients were screened; 69 were excluded. A total of 189 patients with clinically suspected IIH were then evaluated with the diagnostic workup and IIH was confirmed in 111 patients (58.7%). A total of 45% of patients with IIH had a psychiatric comorbidity. Visual fields were worse in patients with IIH+P at baseline (-8.0 vs -6.0 dB; p = 0.04) and after 6 months (-5.5 vs -4.0 dB; p < 0.01) compared with IIH-P. Highly prevalent psychiatric disorders were major depressive disorder (24.3%; n = 27), anxiety or stress-related disorders (24.3%; n = 27), and emotionally unstable personality disorder (6.3%; n = 7). Substance abuse (1.8%), schizophrenia (0.9%), and bipolar disorder (0.9%) were rare. In the general population, prevalence estimates of major depressive disorder and emotionally unstable personality disorder were 1.8%-3.3% and 2%, respectively.

DISCUSSION

Visual fields were significantly worse at baseline and 6 months in IIH+P compared with IIH-P. Psychiatric comorbidities, particularly depression and emotionally unstable personality disorder, were highly prevalent in IIH. Increased awareness of psychiatric disease as a marker for worse visual status may improve patient care.

Metformin for early comorbid glucose dysregulation and schizophrenia spectrum disorders: a pilot double-blind randomized clinical trial

Patients with schizophrenia have exceedingly high rates of metabolic comorbidity including type 2 diabetes and lose 15-20 years of life due to cardiovascular diseases, with early accrual of cardiometabolic disease. In this study, thirty overweight or obese (Body Mass Index (BMI) > 25) participants under 40 years old with schizophrenia spectrum disorders and early comorbid prediabetes or type 2 diabetes receiving antipsychotic medications were randomized, in a double-blind fashion, to metformin 1500 mg/day or placebo (2:1 ratio; n = 21 metformin and n = 9 placebo) for 4 months. The primary outcome measures were improvements in glucose homeostasis (HbA1c, fasting glucose) and insulin resistance (Matsuda index-derived from oral glucose tolerance tests and homeostatic model of insulin resistance (HOMA-IR)). Secondary outcome measures included changes in weight, MRI measures of fat mass and distribution, symptom severity, cognition, and hippocampal volume. Twenty-two patients (n = 14 metformin; n = 8 placebo) completed the trial. The metformin group had a significant decrease over time in the HOMA-IR (p = 0.043) and fasting blood glucose (p = 0.007) vs. placebo. There were no differences between treatment groups in the Matsuda index, HbA1c, which could suggest liver-specific effects of metformin. There were no between group differences in other secondary outcome measures, while weight loss in the metformin arm correlated significantly with decreases in subcutaneous, but not visceral or hepatic adipose tissue. Our results show that metformin improved dysglycemia and insulin sensitivity, independent of weight loss, in a young population with prediabetes/diabetes and psychosis spectrum illness, that is at extremely high risk of early cardiovascular mortality. Trial Registration: This protocol was registered with clinicaltrials.gov (NCT02167620).

Olanzapine-induced insulin resistance may occur via attenuation of central KATP channel-activation

Antipsychotic use is associated with an increased risk of type 2 diabetes. Recent work suggests antipsychotics can induce insulin resistance immediately and independently of weight gain, and that this may occur via the central nervous system (CNS). We have previously shown that the highly effective and widely prescribed antipsychotic, olanzapine inhibits CNS insulin-mediated suppression of hepatic glucose production, but the mechanisms remain unknown. The ATP-sensitive potassium (K_ATP) channel is a key metabolic sensor downstream of hypothalamic insulin signalling, involved in the maintenance of glucose homeostasis. Thus, the possibility arises that olanzapine inhibits central K_ATP channel activation to disrupt glucose metabolism. We replicate that intracerebroventricular (ICV) administration of the K_ATP channel activator, diazoxide, suppresses hepatic glucose production and additionally demonstrate stimulation of peripheral glucose utilization. We report that olanzapine inhibits the effects of central K_ATP channel activation resulting in perturbation of whole body insulin sensitivity, specifically via inhibition of glucose utilization, while leaving central K_ATP channel-mediated suppression of glucose production intact. Perturbation of K_ATP channel action in the CNS could represent a novel mechanism of antipsychotic-induced diabetes.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

The Microbiota-Gut-Brain Axis

The importance of the gut-brain axis in maintaining homeostasis has long been appreciated. However, the past 15 yr have seen the emergence of the microbiota (the trillions of microorganisms within and on our bodies) as one of the key regulators of gut-brain function and has led to the appreciation of the importance of a distinct microbiota-gut-brain axis. This axis is gaining ever more traction in fields investigating the biological and physiological basis of psychiatric, neurodevelopmental, age-related, and neurodegenerative disorders. The microbiota and the brain communicate with each other via various routes including the immune system, tryptophan metabolism, the vagus nerve and the enteric nervous system, involving microbial metabolites such as short-chain fatty acids, branched chain amino acids, and peptidoglycans. Many factors can influence microbiota composition in early life, including infection, mode of birth delivery, use of antibiotic medications, the nature of nutritional provision, environmental stressors, and host genetics. At the other extreme of life, microbial diversity diminishes with aging. Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life. Much recent work has implicated the gut microbiota in many conditions including autism, anxiety, obesity, schizophrenia, Parkinson’s disease, and Alzheimer’s disease. Animal models have been paramount in linking the regulation of fundamental neural processes, such as neurogenesis and myelination, to microbiome activation of microglia. Moreover, translational human studies are ongoing and will greatly enhance the field. Future studies will focus on understanding the mechanisms underlying the microbiota-gut-brain axis and attempt to elucidate microbial-based intervention and therapeutic strategies for neuropsychiatric disorders.

Preclinical and Clinical Sex Differences in Antipsychotic-Induced Metabolic Disturbances: A Narrative Review of Adiposity and Glucose Metabolism

Antipsychotic (AP) medications are associated with an increased risk of developing metabolic side effects including weight gain, type 2 diabetes (T2D), dyslipidemia, and hypertension. In the majority of clinical studies, females on APs are noted to gain more weight, and are more likely to be diagnosed with metabolic syndrome when compared to males. However, the data is less clear when comparing sex disparities associated with other specific AP-induced metabolic risk factors. Accumulating evidence has demonstrated a role for AP-induced adipose tissue accumulation as well as whole body glucose dysregulation in male models that is independent of changes in body weight. The purpose of this narrative review is to explore the susceptibility of males and females to changes in adiposity and glucose metabolism across clinical and preclinical models of AP treatment. It is important that future research examining AP-induced metabolic side effects analyzes outcomes by sex to help clarify risk and identify the mechanisms of adverse event development to improve safe prescribing of medications.

Opinions of Primary Care Clinicians and Psychiatrists on Monitoring the Metabolic Effects of Antipsychotics

OBJECTIVE

Although people with severe mental illness (SMI) have high rates of diabetes and other metabolic disorders, adherence to recommended screening guidelines is low. This study aimed to compare primary care clinicians' and psychiatrists' attitudes toward metabolic monitoring and treatment of patients with SMI.

METHODS

Primary care clinicians and psychiatrists within 1 large urban integrated public health system were recruited to participate in this online survey study. Multivariate logistic regression analyses were used to examine if clinician characteristics were associated with attitudes or perceived barriers toward metabolic monitoring and treatment.

RESULTS

Response rates were 77% (164/214) of primary care providers and 69% (56/81) of psychiatrists completing the survey. There were no significant differences in age or race/ethnicity between provider groups, although primary care clinicians were more likely to be women when compared with the psychiatrists (69% vs 39%, P < .001). Psychiatrists were more likely than primary care clinicians to believe that psychiatrists should conduct metabolic monitoring even if patients had a primary care provider (80% vs 60%, P = .011) However, fewer psychiatrists than primary care clinicians believed that psychiatrists should treat identified cardiometabolic abnormalities (15% vs 42%, P < .001).

CONCLUSION

Systemic problems with care coordination and these varying expectations likely contribute to poor cardiometabolic outcomes in this vulnerable population.

Glucagon-like peptide-1 receptor agonists for antipsychotic-associated cardio-metabolic risk factors: A systematic review and individual participant data meta-analysis

AIMS

To evaluate if glucagon-like peptide-1 receptor agonists (GLP-1RAs) reduce antipsychotic-associated body weight gain in patients with schizophrenia, when compared to controls.

MATERIALS AND METHODS

We systematically searched PubMed/EMBASE/PsycINFO/Cochrane using the search terms '(antipsychotic and GLP-1RA)'. Individual participant data from studies randomizing patients to GLP-1RA or control were meta-analysed. The primary outcome was difference in body weight between GLP-1RA and control; secondary outcomes included cardio-metabolic variables and adverse drug reactions (ADRs). Multiple linear regression was conducted including sex, age, psychosis severity, metabolic variable, ADRs, and GLP-1RA agent.

RESULTS

Three studies (exenatide once-weekly = 2; liraglutide once-daily = 1) provided participant-level data (n = 164, age = 40.0 ± 11.1 years, body weight = 105.8 ± 20.8 kg). After 16.2 ± 4.0 weeks of treatment, body weight loss was 3.71 kg (95% CI = 2.44-4.99 kg) greater for GLP-1RA versus control (p < 0.001), number-needed-to-treat ≥5% body weight loss = 3.8 (95% CI = 2.6-7.2). Waist circumference, body mass index, HbA1c, fasting glucose and visceral adiposity were each significantly lower with GLP-1RA. Sex, age, psychosis severity, nausea, any ADR, and GLP-1RA agent did not significantly impact outcomes. Body weight loss with GLP-1RAs was greater for clozapine/olanzapine-treated patients (n = 141) than other antipsychotics (n = 27) (4.70 kg, 95% CI = 3.13-6.27 vs. 1.5 kg, 95% CI = -1.47-4.47) (p < 0.001). Nausea was more common with GLP-1RAs than control (53.6% vs. 27.5%, p = 0.002, number-needed-to-harm = 3.8).

CONCLUSION

GLP-1RAs are effective and tolerable for antipsychotic-associated body weight gain, particularly clozapine/olanzapine-treated patients. With few included patients, further studies are required before making routine use recommendations for GLP-1RAs.

The Complex Relationship between Antipsychotic-Induced Weight Gain and Therapeutic Benefits: A Systematic Review and Implications for Treatment

Background: Antipsychotic-induced weight gain (AIWG) and other adverse metabolic effects represent serious side effects faced by many patients with psychosis that can lead to numerous comorbidities and which reduce the lifespan. While the pathophysiology of AIWG remains poorly understood, numerous studies have reported a positive association between AIWG and the therapeutic benefit of antipsychotic medications.

Objectives: To review the literature to (1) determine if AIWG is consistently associated with therapeutic benefit and (2) investigate which variables may mediate such an association.

Data Sources: MEDLINE, Google Scholar, Cochrane Database and PsycINFO databases were searched for articles containing all the following exploded MESH terms: schizophrenia [AND] antipsychotic agents/neuroleptics [AND] (weight gain [OR] lipids [OR] insulin [OR] leptin) [AND] treatment outcome. Results were limited to full-text, English journal articles.

Results: Our literature search uncovered 31 independent studies which investigated an AIWG-therapeutic benefit association with a total of 6063 enrolled individuals diagnosed with schizophrenia or another serious mental illness receiving antipsychotic medications. Twenty-two studies found a positive association while, 10 studies found no association and one study reported a negative association. Study variables including medication compliance, sex, ethnicity, or prior antipsychotic exposure did not appear to consistently affect the AIWG-therapeutic benefit relationship. In contrast, there was some evidence that controlling for baseline BMI/psychopathology, duration of treatment and specific agent studied [i.e., olanzapine (OLZ) or clozapine (CLZ)] strengthened the relationship between AIWG and therapeutic benefit.

Limitations: There were limitations of the reviewed studies in that many had small sample sizes, and/or were retrospective. The heterogeneity of the studies also made comparisons difficult and publication bias was not controlled for.

Conclusions: An AIWG-therapeutic benefit association may exist and is most likely to be observed in OLZ and CLZ-treated patients. The clinical meaningfulness of this association remains unclear and weight gain and other metabolic comorbidities should be identified and treated to the same targets as the general population. Further research should continue to explore the links between therapeutic benefit and metabolic health with emphasis on both pre-clinical work and well-designed prospective clinical trials examining metabolic parameters associated, but also occurring independently to AIWG.

Molecular Mechanisms of Antipsychotic Drug-Induced Diabetes

Antipsychotic drugs (APDs) are widely prescribed to control various mental disorders. As mental disorders are chronic diseases, these drugs are often used over a life-time. However, APDs can cause serious glucometabolic side-effects including type 2 diabetes and hyperglycaemic emergency, leading to medication non-compliance. At present, there is no effective approach to overcome these side-effects. Understanding the mechanisms for APD-induced diabetes should be helpful in prevention and treatment of these side-effects of APDs and thus improve the clinical outcomes of APDs. In this review, the potential mechanisms for APD-induced diabetes are summarized so that novel approaches can be considered to relieve APD-induced diabetes. APD-induced diabetes could be mediated by multiple mechanisms: (1) APDs can inhibit the insulin signaling pathway in the target cells such as muscle cells, hepatocytes and adipocytes to cause insulin resistance; (2) APD-induced obesity can result in high levels of free fatty acids (FFA) and inflammation, which can also cause insulin resistance. (3) APDs can cause direct damage to β-cells, leading to dysfunction and apoptosis of β-cells. A recent theory considers that both β-cell damage and insulin resistance are necessary factors for the development of diabetes. In high-fat diet-induced diabetes, the compensatory ability of β-cells is gradually damaged, while APDs cause direct β-cell damage, accounting for the severe form of APD-induced diabetes. Based on these mechanisms, effective prevention of APD-induced diabetes may need an integrated approach to combat various effects of APDs on multiple pathways.

In male rats, the ability of central insulin to suppress glucose production is impaired by olanzapine, whereas glucose uptake is left intact

BACKGROUND

Insulin receptors are widely expressed in the brain and may represent a crossroad between metabolic and cognitive disorders. Although antipsychotics, such as olanzapine, are the cornerstone treatment for schizophrenia, they are associated with high rates of type 2 diabetes and lack efficacy for illness-related cognitive deficits. Historically, this risk of diabetes was attributed to the weight gain propensity of antipsychotics, but recent work suggests antipsychotics can have weight-independent diabetogenic effects involving unknown brain-mediated mechanisms. Here, we examined whether antipsychotics disrupt central insulin action, hypothesizing that olanzapine would impair the well-established ability of central insulin to supress hepatic glucose production.

METHODS

Pancreatic euglycemic clamps were used to measure glucose kinetics alongside a central infusion of insulin or vehicle into the third ventricle. Male rats were pretreated with olanzapine or vehicle per our established model of acute olanzapine-induced peripheral insulin resistance. Groups included (central-peripheral) vehicle-vehicle (n = 11), insulin-vehicle (n = 10), insulin-olanzapine (n = 10) and vehicle-olanzapine (n = 8).

RESULTS

There were no differences in peripheral glucose or insulin levels. Unexpectedly, we showed that central insulin increased glucose uptake, and this effect was not perturbed by olanzapine. We replicated suppression of glucose production by insulin (clamp relative to basal: 77.9% ± 13.1%, all p < 0.05), an effect abolished by olanzapine (insulin-olanzapine: 7.7% ± 14%).

LIMITATIONS

This study used only male rats and an acute dose of olanzapine.

CONCLUSION

To our knowledge, this is the first study suggesting olanzapine may impair central insulin sensing, elucidating a potential mechanism of antipsychotic-induced diabetes and opening avenues of investigation related to domains of schizophrenia psychopathology.

Adiposity-independent hypoadiponectinemia as a potential marker of insulin resistance and inflammation in schizophrenia patients treated with second generation antipsychotics

OBJECTIVE

The purpose of this study was to explore body fat independent effect of second generation antipsychotics (SGAs) on measures of glucose and adipokine homeostasis, and markers of inflammation.

METHOD

Eight non-diabetic men with schizophrenia (age: 55±3years, BMI: 29.7±1.2kg/m(2)) on SGAs were studied after an overnight fast. DXA and single-cut CT of abdomen were respectively used for the assessment of total body and abdominal fat. Blood samples were collected for measurements of glucose, insulin, leptin, adiponectin, C-reactive protein (CRP), and TNF-α. Data in schizophrenic subjects were compared to eight age (55±2.8years) and BMI (29.6±1.1kg/m(2)) matched healthy men.

RESULTS

The results were significant for markedly decreased serum adiponectin in schizophrenia patients (4.6±0.9 vs 11.1±1.5ng/mL, p=0.001). Lower levels of adiponectin in schizophrenia men were associated with significant increases in insulin resistance (4.2±0.7 vs 1.7±0.4, p=0.004), CRP (3.5±1.2 vs 1.2±0.3, p=0.037), and leptin (12±1.4 vs 8.5±1.4ng/mL, p=0.05). Various measures of adiposity, including fat mass index (FMI) and abdominal fat were not different in the two study groups.

CONCLUSIONS

These findings in the context of comparable age and total body/abdominal fat mass are assumed to be either disease specific, and/or treatment inflicted. The definitive invoking etiology and a presumptive role of hypoadiponectinemia in the development of insulin resistance and increased risk of inflammation warrant future investigation.

Second-generation antipsychotics and adiponectin levels in schizophrenia: A comparative meta-analysis

People with schizophrenia treated with second-generation antipsychotics (SGAs) have lower plasma adiponectin levels, as compared with general population, that may lead to metabolic abnormalities. However, the contribution of different SGAs on adiponectin dysregulation is still unclear. The objective of this systematic review and meta-analysis was to estimate differences in adiponectin levels among people with schizophrenia treated with different SGAs. We systematically searched for observational studies published up to March 2015 in main electronic databases. Different SGAs were included if data on adiponectin were available from at least three different samples involving as a minimum five participants per treatment arm. Standardized mean differences with relevant 95% confidence intervals were generated. I(2) was used to test heterogeneity among studies. Eight studies were included with data suitable for carrying out four different comparisons: Clozapine vs. Olanzapine (including n=877 individuals with schizophrenia); Clozapine vs. Risperidone (n=660); Olanzapine vs. Risperidone (n=738); Quetiapine vs. Risperidone (n=186). There were no differences on adiponectin levels between people taking Clozapine and those taking Olanzapine (p=0.86), but high heterogeneity was detected (I(2)=82%). Both individuals taking Clozapine (p<0.001; I(2)=0%) and those taking Olanzapine (p=0.02; I(2)=9%), but not subjects treated with Quetiapine (p=0.47; I(2)=0%), had adiponectin levels significantly lower than people taking Risperidone. Our findings are consistent with previous evidence showing greater metabolic abnormalities attributable to Clozapine and Olanzapine, as compared with other SGAs. Although mechanisms whereby both these SGAs influence adiponectin remain unexplained, its reduction might mediate relevant abnormalities. Prospective evaluations of long-term effects of different SGAs on adiponectin are needed.

Association of adipokines with metabolic disorders in patients with schizophrenia: Results of comparative study with mental healthy cohort

AIM

The role of adipose tissue hormones, adipokines, in formation of metabolic disorders in schizophrenia is not fully understood. The aim was to investigate the association of leptin and adiponectin plasma levels with metabolic parameters in antipsychotic treated patients with schizophrenia and in the group of age, gender and body mass index matched mental healthy persons.

METHODS

One hundred patients with diagnosis of schizophrenia, who took antipsychotic medication, and equal number of control subjects, were enrolled for cross-sectional evaluation. Fasting blood plasma levels of glucose, lipids, insulin, adiponectin, leptin concentrations and insulin resistance HOMA index were determined.

RESULTS

In both groups plasma leptin concentration positively correlated with body mass index, insulin plasma level and HOMA index, while adiponectin level had negative correlations with adiposity measures and positive associations with high density lipoprotein cholesterol content. At the same time, in schizophrenia group, but not in control subjects, leptin level positively associated with cholesterol and triglycerides concentrations and adiponectin negatively correlated with plasma insulin content, HOMA index and triglycerides levels. After controlling for confounders significant correlations remained for leptin concentration with HOMA index and plasma triglycerides level in schizophrenic patients and for adiponectin concentration with plasma high density lipoprotein cholesterol concentrations in both studied groups.

CONCLUSIONS

Both adipokines associate with metabolic parameters in antipsychotic treated patients with schizophrenia. Leptin can play more specific role in pathogenesis of metabolic syndrome in schizophrenic persons than in mental healthy subjects.

Reduced insulin-receptor mediated modulation of striatal dopamine release by basal insulin as a possible contributing factor to hyperdopaminergia in schizophrenia

Schizophrenia is a severe and chronic neuropsychiatric disorder which affects 1% of the world population. Using the brain imaging technique positron emission tomography (PET) it has been demonstrated that persons with schizophrenia have greater dopamine transmission in the striatum compared to healthy controls. However, little progress has been made as to elucidating other biological mechanisms which may account for this hyperdopaminergic state in this disease. Studies in animals have demonstrated that insulin receptors are expressed on midbrain dopamine neurons, and that insulin from the periphery acts on these receptors to modify dopamine transmission in the striatum. This is pertinent given that several lines of evidence suggest that insulin receptor functioning may be abnormal in the brains of persons with schizophrenia. Post-mortem studies have shown that persons with schizophrenia have less than half the number of cortical insulin receptors compared to healthy persons. Moreover, these post-mortem findings are unlikely due to the effects of antipsychotic treatment; studies in cell lines and animals suggest antipsychotics enhance insulin receptor functioning. Further, hyperinsulinemia - even prior to antipsychotic use - seems to be related to less psychotic symptoms in patients with schizophrenia. Collectively, these data suggest that midbrain insulin receptor functioning may be abnormal in persons with schizophrenia, resulting in reduced insulin-mediated regulation of dopamine transmission in the striatum. Such a deficit may account for the hyperdopaminergic state observed in these patients and would help guide the development of novel treatment strategies. We hypothesize that, (i) insulin receptor expression and/or function is reduced in midbrain dopamine neurons in persons with schizophrenia, (ii) basal insulin should reduce dopaminergic transmission in the striatum via these receptors, and (iii) this modulation of dopaminergic transmission by basal insulin is reduced in the brains of persons with schizophrenia.

Plasma adiponectin levels in schizophrenia and role of second-generation antipsychotics: a meta-analysis

BACKGROUND

People with schizophrenia are more likely than general population to suffer from metabolic abnormalities, with second-generation antipsychotics (SGAs) increasing the risk. Low plasma adiponectin levels may lead to metabolic dysregulations but evidence in people with schizophrenia, especially for the role of SGAs, is still inconclusive.

OBJECTIVE

To compare plasma adiponectin levels between people with schizophrenia and healthy controls, and to estimate the relative effect of schizophrenia and SGAs on adiponectin.

METHODS

We performed a systematic review and meta-analysis of observational studies published up to 13 June 2014 in main electronic databases. Pooled standardized mean differences (SMDs) between index and control groups were generated. Appropriate subanalyses and additional subgroup analyses were carried out.

RESULTS

Data from 2735 individuals, 1013 with and 1722 without schizophrenia, respectively, were analysed. Schizophrenia was not associated with lower adiponectin levels (SMD of -0.28, 95%CI: -0.59, 0.04; p=0.09). However, individuals with schizophrenia taking SGAs had plasma levels significantly lower than controls (p=0.002), which was not the case of drug free/drug naïve subjects (p=0.52). As regards single antipsychotic drugs clozapine (p<0.001) and olanzapine (p=0.04)--but not risperidone (p=0.88)--were associated with adiponectin levels lower than controls.

CONCLUSIONS

People with schizophrenia per se may not have levels of adiponectin lower than controls, though treatment with SGAs is associated with this metabolic abnormality. This bears clinical significance because of hypoadiponectinemia involvement in cardiovascular diseases, even if mechanisms whereby SGAs affect adiponectin remain unexplained. Longitudinal studies evaluating long-term effects of SGAs on adiponectin are needed.

Plasma omentin levels in drug-free patients with schizophrenia

AIMS

We aimed to investigate plasma omentin concentrations in non-obese, drug-free patients with schizophrenia in comparison with healthy volunteers.

METHOD

Thirty-two patients with schizophrenia and 33 control subjects were recruited. Plasma omentin levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Plasma levels of omentin (ng/ml) were found to be markedly lower in patients with schizophrenia (median = 7.7, 25th percentile = 6.3, 75th percentile = 604.9) than in controls (median = 486, 25th percentile = 326, 75th percentile = 794.2, p < 0.01). No significant difference was found between drug-free (n = 23) and drug-naive (n = 9) patients with respect to plasma omentin levels. Omentin concentrations correlated negatively with severity of illness, suggesting that patients with more severe pathology had lower fasting levels of omentin (n = 32; r = -0.387; p = 0.029).

CONCLUSION

The present results suggest that plasma omentin levels are decreased in physically healthy, non-obese, antipsychotic-free patients with schizophrenia when compared with physically and mentally healthy individuals. To our knowledge, this is the first study that demonstrated the association between omentin and schizophrenia.

The effects of atypical antipsychotic usage duration on serum adiponectin levels and other metabolic parameters

OBJECTIVE

Although atypical antipsychotics are well-tolerated and effective treatment options for schizophrenia, they have metabolic side effects, including weight gain and increased risk of Type II Diabetes Mellitus (DM). Adiponectin, produced exclusively in adipocytes, is the most abundant serum adipokine. Low levels of adiponectin are correlated with DM, insulin resistance and coronary heart disease. Usage of atypical antipsychotics may create a risk of metabolic syndrome. The aim of this study was to evaluate the effects of antipsychotic usage on parameters related to development of metabolic syndrome.

MATERIALS AND METHODS

A total of 27 patients (n=27) (13 women and 14 men) were recruited from our out-patient psychiatry clinic. All patients had been treated with atypical antipsychotics for at least 3 months and were in remission. Patients were evaluated for levels of HDL (High Density Lipoprotein), LDL (Low Density Lipoprotein), TG (Triglyceride) total cholesterol and fasting blood glucose, body weight, BMI (Body Mass Index), waist circumference and serum adiponectin levels.

RESULTS

Serum adiponectin levels were significantly lower (p:0.000) and body weights were significantly higher (p:0.003) in the patients who had been using atypical antipsychotics for longer than a year in comparison to patients who had been using atypical antipsychotics for one year or less.

CONCLUSION

Our findings supported the hypothesis that the length of administration of atypical antipsychotics has an effect on metabolic changes. They also highlight the fact that when investigating metabolic changes generated by atypical antipsychotic effects, the length of time that the patient has been on the atypical antipsychotics should also be considered.

Antipsychotics-induced metabolic alterations: focus on adipose tissue and molecular mechanisms

The use of antipsychotic drugs for the treatment of mood disorders and psychosis has increased dramatically over the last decade. Despite its consumption being associated with beneficial neuropsychiatric effects in patients, atypical antipsychotics (which are the most frequently prescribed antipsychotics) use is accompanied by some secondary adverse metabolic effects such as weight gain, dyslipidemia and glucose intolerance. The molecular mechanisms underlying these adverse effects are not fully understood but have been suggested to involve a dysregulation of adipose tissue homeostasis. As such, the aim of this paper is to review and discuss the role of adipose tissue in the development of secondary adverse metabolic effects induced by atypical antipsychotics. Data analyzed in this article suggest that atypical antipsychotics may increase adipose tissue (particularly visceral adipose tissue) lipogenesis, differentiation/hyperplasia, pro-inflammatory mediator secretion and insulin resistance and decrease adipose tissue lipolysis. Consequently, patients receiving antipsychotic medication could be at risk of developing obesity, type 2 diabetes and cardiovascular disease. A better knowledge of the impact of these drugs on adipose tissue homeostasis may unveil strategies to develop novel antipsychotic drugs with less adverse metabolic effects and to develop adjuvant therapies (e.g. behavioral and nutritional therapies) to neuropsychiatric patients receiving antipsychotic medication.

Molecular pathophysiology of metabolic effects of antipsychotic medications

Antipsychotic medications are associated with major metabolic changes that contribute to medical morbidity and a significantly shortened life span. The mechanisms for these changes provide us with a broader understanding of central nervous and peripheral organ-mediated metabolic regulation. This paper reviews an extensive literature regarding putative mechanisms for effects of antipsychotic medications on weight regulation and glucose homeostasis as well as potential inherent metabolic risks of schizophrenia itself. We present a model suggesting that peripheral antipsychotic targets play a critical role in drug-induced weight gain and diabetes. We propose that a better understanding of these mechanisms will be crucial to developing improved treatments for serious mental illnesses as well as providing potentially novel therapeutic targets of metabolic disorders including diabetes.

No evidence for a role of the peroxisome proliferator-activated receptor gamma (PPARG) and adiponectin (ADIPOQ) genes in antipsychotic-induced weight gain

Antipsychotics frequently cause changes in glucose metabolism followed by development of weight gain and/or diabetes. Recent findings from our group indicated an influence of glucose-related genes on this serious side effect. With this study, we aimed to extend previous research and performed a comprehensive study on the peroxisome proliferator-activated receptor gamma (PPARG) and the adiponectin (ADIPOQ) genes. In 216 schizophrenic patients receiving antipsychotics for up to 14 weeks, we investigated single-nucleotide polymorphisms in or near PPARG (N=24) and ADIPOQ (N=18). Statistical analysis was done using ANCOVA in SPSS. Haplotype analysis was performed in UNPHASED 3.1.4 and Haploview 4.2. None of the PPARG or ADIPOQ variants showed significant association with antipsychotic-induced weight gain in our combined sample or in a refined subsample of patients of European ancestry treated with clozapine or olanzapine after correction for multiple testing. Similarly, no haplotype association could withstand multiple test correction. Although we could not find a significant influence of ADIPOQ and PPARG on antipsychotic-induced weight gain, our comprehensive examination of these two genes contributes to understanding the biology of this serious side effect. More research on glucose metabolism genes is warranted to elucidate their role in metabolic changes during antipsychotic treatment.

Cytokine and adipokine alterations in patients with schizophrenia treated with clozapine

Metabolic syndrome is associated with both schizophrenia and antipsychotic medication, especially clozapine, with alterations in inflammatory cytokines and adipokines. However, the data in this field is heterogeneous and the sample sizes of the patients are limited. In this study we assessed the serum levels of cytokines/adipokines IL-6, IL-1Ra, hs-CRP and adiponectin, and components of metabolic syndrome in 190 patients with treatment resistant schizophrenia treated with clozapine. Substantial metabolic comorbidity was found in this patient group; overweight/obesity, smoking, hypertriglyceridemia, low HDL-cholesterol, high HOMA-IR, low adiponectin levels, elevated hs-CRP levels and elevated IL-1Ra levels. Elevated IL-1Ra levels are associated with insulin resistance, obesity and hypertriglyceridemia. Low adiponectin levels were associated with hypertriglyceridemia, low HDL cholesterol and high glucose, and in male patients also with obesity and high IL-1Ra levels. After controlling for confounding factors age and smoking, levels of IL-1Ra and hs-CRP associated with obesity, and the levels of IL-6 associated with obesity in female patients. We conclude that there are partly gender dependent cytokine and adipokine alterations in patients with schizophrenia on clozapine treatment associated with metabolic comorbidity. The genetic background of these cytokine alterations needs to be further investigated.

In vivo pharmacological evaluations of novel olanzapine analogues in rats: a potential new avenue for the treatment of schizophrenia

Olanzapine (Olz) is one of the most effective antipsychotic drugs commonly used for treating schizophrenia. Unfortunately, Olz administration is associated with severe weight gain and metabolic disturbances. Both patients and clinicians are highly interested in the development of new antipsychotics which are as effective as atypical antipsychotics but which have a lower propensity to induce metabolic side effects. In the present study, we examined two new derivatives of Olz; OlzEt (2-ethyl-4-(4'-methylpiperazin-1'-yl)-10Hbenzo[b]thieno[2,3-e][1,4]diazepine), and OlzHomo (2-ethyl-4-(4'-methyl-1',4'-diazepan-1'-yl)-10H-benzo[b]thieno[2,3-e] [1,4]diazepine), for their tendency to induce weight gain in rats. Weight gain and metabolic changes were measured in female Sprague Dawley rats. Animals were treated orally with Olz, OlzEt, OlzHomo (3 or 6 mg/kg/day), or vehicle (n = 8), three times daily at eight-hour intervals for 5 weeks. Furthermore, a phencyclidine (PCP)-treated rat model was used to examine the prevention of PCP-induced hyperlocomotor activity relevant for schizophrenia therapy. Male Sprague Dawley rats were pre-treated with a single dose (3 mg/kg/day) of Olz, OlzEt, OlzHomo, or vehicle (n = 12), for 2 weeks. Locomotor activity was recorded following a subcutaneous injection with either saline or PCP (10 mg/kg). Olz was found to induce weight gain, hyperphagia, visceral fat accumulation, and metabolic changes associated with reduced histamatergic H1 receptor density in the hypothalamus of treated rats. In contrast, OlzEt and OlzHomo presented promising antipsychotic effects, which did not induce weight gain or fat deposition in the treated animals. Behavioural analysis showed OlzEt to attenuate PCP-induced hyperactivity to a level similar to that of Olz; however, OlzHomo showed a lower propensity to inhibit these stereotyped behaviours. Our data suggest that the therapeutic effectiveness of OlzHomo may be delivered at a higher dose than that of Olz and OlzEt. Overall, OlzEt and OlzHomo may offer a better pharmacological profile than Olz for treating patients with schizophrenia. Clinical trials are needed to test this hypothesis.

Second generation antipsychotic-induced type 2 diabetes: a role for the muscarinic M3 receptor

Second generation antipsychotics (SGAs) are widely prescribed to treat various disorders, most notably schizophrenia and bipolar disorder; however, SGAs can cause abnormal glucose metabolism that can lead to insulin-resistance and type 2 diabetes mellitus side-effects by largely unknown mechanisms. This review explores the potential candidature of the acetylcholine (ACh) muscarinic M3 receptor (M3R) as a prime mechanistic and possible therapeutic target of interest in SGA-induced insulin dysregulation. Studies have identified that SGA binding affinity to the M3R is a predictor of diabetes risk; indeed, olanzapine and clozapine, SGAs with the highest clinical incidence of diabetes side-effects, are potent M3R antagonists. Pancreatic M3Rs regulate the glucose-stimulated cholinergic pathway of insulin secretion; their activation on β-cells stimulates insulin secretion, while M3R blockade decreases insulin secretion. Genetic modification of M3Rs causes robust alterations in insulin levels and glucose tolerance in mice. Olanzapine alters M3R density in discrete nuclei of the hypothalamus and caudal brainstem, regions that regulate glucose homeostasis and insulin secretion through vagal innervation of the pancreas. Furthermore, studies have demonstrated a dynamic sensitivity of hypothalamic and brainstem M3Rs to altered glucometabolic status of the body. Therefore, the M3R is in a prime position to influence glucose homeostasis through direct effects on pancreatic β-cells and by potentially altering signalling in the hypothalamus and brainstem. SGA-induced insulin dysregulation may be partly due to blockade of central and peripheral M3Rs, causing an initial disruption to insulin secretion and glucose homeostasis that can progressively lead to insulin resistance and diabetes during chronic treatment.

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.

Effects of olanzapine on muscarinic M3 receptor binding density in the brain relates to weight gain, plasma insulin and metabolic hormone levels

The second generation antipsychotic drug (SGA) olanzapine has an efficacy to treat schizophrenia, but can cause obesity and type II diabetes mellitus. Cholinergic muscarinic M3 receptors (M3R) are expressed on pancreatic β-cells and in the brain where they influence insulin secretion and may regulate other metabolic hormones via vagal innervation of the gastrointestinal tract. Olanzapine's M3R antagonism is an important risk factor for its diabetogenic liability. However, the effects of olanzapine on central M3Rs are unknown. Rats were treated with 0.25, 0.5, 1.0 or 2.0 mg olanzapine/kg or vehicle (3×/day, 14-days). M3R binding densities in the hypothalamic arcuate (Arc) and ventromedial nuclei (VMH), and dorsal vagal complex (DVC) of the brainstem were investigated using [3H]4-DAMP plus pirenzepine and AF-DX116. M3R binding correlations to body weight, food intake, insulin, ghrelin and cholecystokinin (CCK) were analyzed. Olanzapine increased M3R binding density in the Arc, VMH and DVC, body weight, food intake, circulating plasma ghrelin and CCK levels, and decreased plasma insulin and glucose. M3R negatively correlated to insulin, and positively correlated to ghrelin, CCK, food intake and body weight. Increased M3R density is a compensatory up-regulation in response to olanzapine's M3R antagonism. Olanzapine acts on M3R in regions of the brain that control food intake and insulin secretion. Olanzapine's M3R blockade in the brain may inhibit the acetylcholine pathway for insulin secretion. These findings support a role for M3Rs in the modulation of insulin, ghrelin and CCK via the vagus nerve and provide a mechanism for olanzapine's diabetogenic and weight gain liability.

Gender-dependent consequences of chronic olanzapine in the rat: effects on body weight, inflammatory, metabolic and microbiota parameters

RATIONALE

Atypical antipsychotic drugs (AAPDs) such as olanzapine have a serious side effect profile including weight gain and metabolic dysfunction, and a number of studies have suggested a role for gender in the susceptibility to these effects. In recent times, the gut microbiota has been recognised as a major contributor to the regulation of body weight and metabolism. Thus, we investigated the effects of olanzapine on body weight, behaviour, gut microbiota and inflammatory and metabolic markers in both male and female rats.

METHODS

Male and female rats received olanzapine (2 or 4 mg/kg/day) or vehicle for 3 weeks. Body weight, food and water intake were monitored daily. The faecal microbial content was assessed by 454 pyrosequencing. Plasma cytokines (tumour necrosis alpha, interleukin 8 (IL-8), interleuin-6 and interleukin 1-beta (IL-1β)) as well as expression of genes including sterol-regulatory element binding protein-1c and CD68 were analysed.

RESULTS

Olanzapine induced significant body weight gain in the female rats only. Only female rats treated with olanzapine (2 mg/kg) had elevated plasma levels of IL-8 and IL-1β, while both males and females had olanzapine-induced increases in adiposity and evidence of macrophage infiltration into adipose tissue. Furthermore, an altered microbiota profile was observed following olanzapine treatment in both genders.

CONCLUSIONS

This study furthers the theory that gender may impact on the nature of, and susceptibility to, certain side effects of antipsychotics. In addition, we demonstrate, what is to our knowledge the first time, an altered microbiota associated with chronic olanzapine treatment.

Differential effects of olanzapine and risperidone on plasma adiponectin levels over time: results from a 3-month prospective open-label study

Second-generation antipsychotics (SGA), especially clozapine and olanzapine, are associated with an increased metabolic risk. Recent research showed that plasma adiponectin levels, an adipocyte-derived hormone that increases insulin sensitivity, vary in the same way in schizophrenic patients as in the general population according to gender, adiposity and metabolic syndrome (MetS). The aim of the present study was to investigate whether different SGAs differentially affect plasma adiponectin levels independent of body mass index (BMI) and MetS status. 113 patients with schizophrenia (65.5% males, 32.3years old) who were free of antipsychotic medication were enrolled in this open-label prospective single-center study and received either risperidone (n=54) or olanzapine (n=59). They were followed prospectively for 12weeks. Average daily dose was 4.4mg/day for risperidone and 17.4mg/day for olanzapine. Plasma adiponectin levels as well as fasting metabolic parameters were measured at baseline, 6weeks and 12weeks. The two groups had similar baseline demographic and metabolic characteristics. A significant increase in body weight was observed over time. This increase was significantly larger in the olanzapine group than in the risperidone group (+7.0kg versus +3.1kg, p<0.0002). Changes in fasting glucose and insulin levels and in HOMA-IR, an index of insulin resistance, were not significantly different in both treatment groups. MetS prevalence increased significantly more in the olanzapine group as compared to the risperidone groups where the prevalence did not change over time. We observed a significant (p=0.0015) treatment by time interaction showing an adiponectin increase in the risperidone-treated patients (from 10,154 to 11,124ng/ml) whereas adiponectin levels decreased in olanzapine treated patients (from 11,280 to 8988ng/ml). This effect was independent of BMI and the presence/absence of MetS. The differential effect of antipsychotic treatment (risperidone versus olanzapine) on plasma adiponectin levels over time, independent of changes in waist circumference and antipsychotic dosing, suggests a specific effect on adipose tissues, similar to what has been observed in animal models. The observed olanzapine-associated reduction in plasma adiponectin levels may at least partially contribute to the increased metabolic risk of olanzapine compared to risperidone.

Guideline concordant monitoring of metabolic risk in people treated with antipsychotic medication: systematic review and meta-analysis of screening practices

BACKGROUND

Despite increased cardiometabolic risk in individuals with mental illness taking antipsychotic medication, metabolic screening practices are often incomplete or inconsistent.

METHOD

We undertook a systematic search and a PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) meta-analysis of studies examining routine metabolic screening practices in those taking antipsychotics both for patients in psychiatric care before and following implementation of monitoring guidelines.

RESULTS

We identified 48 studies (n=290 534) conducted between 2000 and 2011 in five countries; 25 studies examined predominantly schizophrenia-spectrum disorder populations; 39 studies (n=218 940) examined routine monitoring prior to explicit guidelines; and nine studies (n=71 594) reported post-guideline monitoring. Across 39 studies, routine baseline screening was generally low and above 50% only for blood pressure [69.8%, 95% confidence interval (CI) 50.9-85.8] and triglycerides (59.9%, 95% CI 36.6-81.1). Cholesterol was measured in 41.5% (95% CI 18.0-67.3), glucose in 44.3% (95% CI 36.3-52.4) and weight in 47.9% (95% CI 32.4-63.7). Lipids and glycosylated haemoglobin (HbA1c) were monitored in less than 25%. Rates were similar for schizophrenia patients, in US and UK studies, for in-patients and out-patients. Monitoring was non-significantly higher in case-record versus database studies and in fasting samples. Following local/national guideline implementation, monitoring improved for weight (75.9%, CI 37.3-98.7), blood pressure (75.2%, 95% CI 45.6-95.5), glucose (56.1%, 95% CI 43.4-68.3) and lipids (28.9%, 95% CI 20.3-38.4). Direct head-to-head pre-post-guideline comparison showed a modest but significant (15.4%) increase in glucose testing (p=0.0045).

CONCLUSIONS

In routine clinical practice, metabolic monitoring is concerningly low in people prescribed antipsychotic medication. Although guidelines can increase monitoring, most patients still do not receive adequate testing.

A prospective study of glucose homeostasis in quetiapine-treated schizophrenic patients by using the intravenous glucose tolerance test

Increasing attention has been paid recently to the potential diabetogenic effect of second-generation antipsychotics (SGAs). The objective of this prospective study was to evaluate the effects of quetiapine treatment on pancreatic beta-cell function in SGA-naïve schizophrenic patients. Seventeen schizophrenic subjects completed an eight-week trial. The metabolic parameters were assessed at weeks 0, 2, 4, and 8. We measured glucose homeostasis with the intravenous glucose tolerance test. After the eight-week treatment, body weight and body mass index showed to be significantly increased compared to those at baseline. No significant changes were found in serum levels of fasting glucose, insulin, total cholesterol, and high-density lipoprotein. Insulin resistance and insulin secretion were significantly increased. Incidences of clinically significant weight gain and treatment-emergent metabolic syndrome were 11.8% and 11.8%, respectively. This study result confirms the association of quetiapine treatment and impairment of glucose homeostasis in schizophrenic patients.

Association of serum levels of leptin, ghrelin, and adiponectin in schizophrenic patients and healthy controls

BACKGROUND

Leptin, ghrelin, and adiponectin play important roles in the regulation of body weight, food intake, and energy homeostasis, and have been suggested to be important biomarkers of metabolic syndrome. In this study, we tried to simultaneously investigate the serum levels of leptin, ghrelin, and adiponectin in schizophrenic patients and healthy controls.

METHODS

During a period of 2 years, we recruited 37 schizophrenic patients and 65 healthy controls. The levels of metabolic syndrome-related biomarkers including serum adiponectin, leptin, and ghrelin were measured with an enzyme-linked immunosorbent assay.

RESULTS

On applying analysis of covariance (ANCOVA) with age and body mass index adjustments, the leptin levels of schizophrenic patients (P = 0.038) were found to be higher than those of healthy controls. However, there were no significant differences in the serum levels of ghrelin or adiponectin between these two groups.

CONCLUSION

These results showed that serum leptin levels might be more sensitive than ghrelin or adiponectin levels between schizophrenic patients and healthy controls. However, studies with a large sample size are needed to confirm these results.

Influence of resting energy expenditure on weight gain in adolescents taking second-generation antipsychotics

BACKGROUND & AIMS

Weight gain is an undesirable side effect of second-generation antipsychotics (SGAs). We performed this study to examine the influence of SGAs on resting energy expenditure (REE) and the relationship of REE to weight gain in adolescent patients.

METHODS

Antipsychotic-naïve or quasi-naïve (<72 h of exposure to antipsychotics) adolescent patients taking olanzapine, quetiapine, or risperidone in monotherapy were followed up for one year. We performed a prospective study (baseline, 1, 3, 6, and 12 months after treatment) based on anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry (Deltatrac™ II MBM-200) to measure REE. We also analyzed metabolic and hormonal data and adiponectin concentrations.

RESULTS

Forty-six out of the 54 patients that started treatment attended at least 2 visits, and 16 completed 1 year of follow-up. Patients gained 10.8 ± 6.2 kg (60% in the form of fat mass) and increased their waist circumference by 11.1 ± 5.0 cm after 1 year of treatment. The REE/kg body mass ratio decreased (p = 0.027), and the REE/percentage fat-free mass (FFM) ratio increased (p = 0.007) following the fall in the percentage of FFM during treatment. Weight increase was significantly correlated with the REE/percentage FFM ratio at all the visits (1-3-6-12 months) (r = 0.69, p = 0.004 at 12 months).

CONCLUSIONS

SGAs seem to induce a hypometabolic state (reflected as decreased REE/kg body mass and increased REE/percentage FFM). This could explain, at least in part, the changes in weight and body composition observed in these 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.

Association of the metabolic syndrome with physical activity performance in patients with schizophrenia

AIM

The primary aim of this study was to determine whether the presence of the metabolic syndrome (MetS) limits physical activity (PA) in patients with schizophrenia. A secondary aim was to investigate cross-sectional associations of leisure-time PA, sports participation and PA performance with MetS parameters.

METHODS

Patients with schizophrenia who had MetS (n=37) were compared with those without MetS (n=69). Patients were assessed for PA performance using a 6-minute walk test (6MWT) and PA participation using the Baecke PA questionnaire, as well as for antipsychotic medication dose (expressed in chlorpromazine equivalents), negative symptoms and smoking behaviour.

RESULTS

The two patient groups were similar in age, gender, mean antipsychotic medication dose, negative symptomatology and smoking behaviour. Distance achieved on the 6MWT was 13.7% shorter (P<0.001) in patients with versus patients without MetS (527.6±108.9 m vs 610.0±93.7 m, respectively). Patients with MetS were also significantly less involved in sports activities (P=0.001) and less physically active during leisure time (P=0.002). Also, the distance of the 6MWT was moderately correlated with body mass index (r=-0.44, P<0.001), waist circumference (r=-0.43, P<0.001), sports participation (r=0.60, P<0.001) and leisure-time PA (r=0.42, P<0.001).

CONCLUSION

MetS is associated with poorer PA performance in patients with schizophrenia. The additional burden of MetS places patients with schizophrenia at even greater risk for physical and functional limitations in daily life.

Olanzapine treatment and metabolic dysfunction: a dose response study in female Sprague Dawley rats

Second generation antipsychotics are commonly prescribed for the treatment of schizophrenia, however some can induce metabolic dysfunction side-effects such as weight gain, obesity and diabetes. Clinical reports suggest olanzapine alters satiety signals, although findings appear conflicting. Previous animal model studies have utilised a range of olanzapine dosages, however the dosage that better mimics the human scenario of olanzapine-induced weight gain is unclear. Female Sprague-Dawley rats were treated orally, three times daily with olanzapine (0.25mg/kg, 0.5mg/kg, 1.0mg/kg, 2.0mg/kg), self-administered in a sweet cookie dough pellet at eight-hourly intervals) or vehicle (n=12/group) for 14-days. Olanzapine orally self-administered in multiple doses (eight-hourly intervals) may circumvent a drop in plasma drug concentration and ensure the maintenance of a consistently high olanzapine level in the rat. Olanzapine increased body weight (0.5mg/kg, 1.0mg/kg, 2.0mg/kg), food intake (2.0mg/kg) and feeding efficiency (0.5-2.0mg/kg), with no effect on water intake. Subcutaneous inguinal (1.0mg/kg, 2.0mg/kg) and intra-abdominal perirenal fat were increased (2.0mg/kg), but not interscapula brown adipose tissue. Olanzapine increased circulating ghrelin and cholecystokinin, but had no effect on peptide YY((3-36)). Olanzapine decreased insulin (0.25-2.0mg/kg) and locomotor activity in the open field arena (0.5-2.0mg/kg). A low dosage of 0.25mg/kg olanzapine had no effect on most parameters measured. Olanzapine-induced weight gain is associated with hyperphagia, enhanced feeding efficiency and adiposity, decreased locomotor activity and altered satiety signaling. The animal model used in the present study of self-administered oral olanzapine treatment (t.i.d.) at a dosage range of 0.5-2.0mg/kg (but not 0.25mg/kg) mimics aspects of the clinic.

Increased food intake and energy expenditure following administration of olanzapine to healthy men

Atypical antipsychotic medications like olanzapine (OLZ) induce weight gain and increase the risk of diabetes in patients with schizophrenia. The goal of this study was to assess potential mechanisms of OLZ-induced weight gain and accompanying metabolic effects. Healthy, lean, male volunteers received OLZ and placebo (PBO) in a randomized, double-blind, crossover study. In periods 1 and 2, subjects received OLZ (5 mg for 3 days then OLZ 10 mg for 12 days) or matching PBO separated by a minimum 12-day washout. Twenty-four hour food intake (FI), resting energy expenditure (REE), activity level, metabolic markers, and insulin sensitivity (IS) were assessed. In total, 30 subjects were enrolled and 21 completed both periods. Mean age and BMI were 27 years (range: 18-49 years) and 22.6 +/- 2.2 kg/m(2), respectively. Relative to PBO, OLZ resulted in a 2.62 vs. 0.08 kg increase in body weight (P < 0.001) and 18% (P = 0.052 or 345 kcal) increase in FI. Excluding one subject with nausea and dizziness on the day of OLZ FI measurement, the increase in FI was 547 kcal, (P < 0.05). OLZ increased REE relative to PBO (113 kcal/day, P = 0.003). Significant increases in triglycerides, plasminogen activator inhibitor-I (PAI-I), leptin, and tumor necrosis factor-alpha (TNF-alpha) were observed. No significant differences in activity level or IS were observed. This study provides evidence that OLZ pharmacology drives the early increase in weight through increased FI, without evidence of decreased energy expenditure (EE), activity level, or short-term perturbations in IS.

Dietary cassava, beta-cell function and hyperbolic product loss rate in type 2 diabetes patients from South Kivu

OBJECTIVE

Cassava, a major carbohydrate source in Africa, contains potentially diabetogenic chemicals, although its consumption is not associated with incident diabetes. As it is not known whether cassava intake impairs residual beta-cell function in patients with type 2 diabetes (T2D), our study compared the metabolic phenotypes of diet- and/or oral antidiabetic drug (OAD)-treated T2D patients in South Kivu (Democratic Republic of the Congo) with [Cassava (+); n=147] and without [Cassava (-); n=46] self-reported cassava consumption.

DESIGN & METHODS

A total of 193 patients [male:female (%) 37:63; mean +/-1 SD age: 56+/-11 years] were interviewed to determine the frequency and distribution of eight major dietary carbohydrate (CHO) sources (cassava, plantain, rice, maize, bread, sorghum, potatoes and legumes). Fasting glucose, insulin and lipid levels were obtained after an overnight fast and OAD discontinuation. Cassava (+) and Cassava (-) groups were compared for HOMA indices of insulin sensitivity (S), beta-cell function (B), hyperbolic product (B x S) and B x S loss rate (B x S LR).

RESULTS

Diabetes duration was 6+/-7 years, age at diabetes diagnosis was 51+/-11 years and BMI was 25+/-5 kg/m(2). Cassava intake was reported by 76% of patients, and amounted to 29+/-11% of their daily CHO intake. The Cassava (-) group ate more plantain, maize, bread and potatoes, and less sorghum. Age, gender and age at diabetes diagnosis did not differ between Cassava (+) and (-) patients, nor did BMI, fat mass, waist circumference, lipid profile and metabolic syndrome prevalence. HOMA indices of S, B, B x S and B x S LR did not differ significantly between groups-Cassava (+) vs (-): S, 114+/-56% vs 114+/-60%; B, 34+/-30% vs 39+/-32%; B x S, 38+/-35% vs 40+/-31%; and B x S LR, 1.19+/-0.84% vs 1.09+/-0.65% per year-nor did the glucose-lowering modalities.

CONCLUSION

Cassava consumption in South Kivu is not associated with changes in T2D phenotype or in the glucose homoeostasis determinants S, B, B x S and B x S LR. Cassava consumption does not accelerate beta-cell function loss in such a population, whose markedly compromised glucose homoeostasis renders them vulnerable to environmentally acquired beta-cell impairment.