The role of ghrelin signalling in second-generation antipsychotic-induced weight gain

Allyl isothiocyanate, a TRPA1 agonist, protects against olanzapine-induced hypothalamic and hepatic metabolic aberrations in female mice

Olanzapine, a widely prescribed atypical antipsychotic, poses a great risk to the patient's health by fabricating a plethora of severe metabolic and cardiovascular adverse effects eventually reducing life expectancy and patient compliance. Its heterogenous receptor binding profile has made it difficult to point out a specific cause or treatment for the related side effects. Growing body of evidence suggest that transient receptor potential (TRP) channel subfamily Ankyrin 1 (TRPA1) has pivotal role in pathogenesis of type 2 diabetes and obesity. With this background, we aimed to investigate the role of pharmacological manipulations of TRPA1 channels in antipsychotic (olanzapine)-induced metabolic alterations in female mice using allyl isothiocyanate (AITC) and HC-030031 (TRPA1 agonist and antagonist, respectively). It was found that after 6 weeks of treatment, AITC prevented olanzapine-induced alterations in body weight and adiposity; serum, and liver inflammatory markers; glucose and lipid metabolism; and hypothalamic appetite regulation, nutrient sensing, inflammatory and TRPA1 channel signaling regulating genes. Furthermore, several of these effects were absent in the presence of HC-030031 (TRPA1 antagonist) indicating protective role of TRPA1 agonism in attenuating olanzapine-induced metabolic alterations. Supplementary in-depth studies are required to study TRPA1 channel effect on other aspects of olanzapine-induced metabolic alterations.

Olanzapine, but not haloperidol, exerts pronounced acute metabolic effects in the methylazoxymethanol rat model

AIM

Widely used second-generation antipsychotics are associated with adverse metabolic effects, contributing to increased cardiovascular mortality. To develop strategies to prevent or treat adverse metabolic effects, preclinical models have a clear role in uncovering underlying molecular mechanisms. However, with few exceptions, preclinical studies have been performed in healthy animals, neglecting the contribution of dysmetabolic features inherent to psychotic disorders.

METHODS

In this study, methylazoxymethanol acetate (MAM) was prenatally administered to pregnant Sprague-Dawley rats at gestational day 17 to induce a well-validated neurodevelopmental model of schizophrenia mimicking its assumed pathogenesis with persistent phenotype. Against this background, the dysmetabolic effects of acute treatment with olanzapine and haloperidol were examined in female rats.

RESULTS

Prenatally MAM-exposed animals exhibited several metabolic features, including lipid disturbances. Half of the MAM rats exposed to olanzapine had pronounced serum lipid profile alteration compared to non-MAM controls, interpreted as a reflection of a delicate MAM-induced metabolic balance disrupted by olanzapine. In accordance with the drugs' clinical metabolic profiles, olanzapine-associated dysmetabolic effects were more pronounced than haloperidol-associated dysmetabolic effects in non-MAM rats and rats exposed to MAM.

CONCLUSION

Our results demonstrate metabolic vulnerability in female prenatally MAM-exposed rats, indicating that findings from healthy animals likely provide an underestimated impression of metabolic dysfunction associated with antipsychotics. In the context of metabolic disturbances, neurodevelopmental models possess a relevant background, and the search for adequate animal models should receive more attention within the field of experimental psychopharmacology.

Associations between overweight, obesity, and mental health: a retrospective study among European adults aged 50

Background

The comorbidities associated with overweight and obesity have been well researched and scientifically proven while their relationship to mental health is still not verified.

Methods

This study is aimed at investigating reciprocal associations between obesity and mental health, and is intended to further analyze possible long-term effects using data from the Survey of Health, Ageing and Retirement in Europe (SHARE). In order to do that, waves 4 and 8, conducted in 2010 and 2019/20 of this survey, were analyzed in a cross-lagged panel approach including 16,184 adult Europeans (50+) using multiple linear regression analysis focusing on the Body Mass Index (BMI), depression status and quality of life (QoL).

Results

Findings yield significant cross-lagged effects in one direction regarding BMI predicting QoL and depression state, whereas depression state and QoL do not significantly predict BMI. Findings include people living with obesity, overweight, and underweight showing significantly decreased levels of QoL as well as increased depression scores compared to people of normal weight over a lag time of 10 years, where people living with obesity indicate the strongest effect.

Conclusions

However, results do not confirm reciprocal associations in the long term. Hence, there is a strong need to carry out further research on this issue.

Clinical review: Guide to pharmacological management in pediatric obesity medicine

Introduction

Newer pharmacotherapy agents (anti-obesity medication [AOM]) are revolutionizing the management of children and adolescents with obesity. Previously, treatment based on intensive behavioral therapy involved many patient and family contact hours and yielded improvements in obesity status of 1-3 percent of the 95th percentile of the body mass index (BMI). Newer AOMs are yielding more clinically significant improvement of 5-18 percent. This review provides guidance for practitioners in the care of children and adolescents with obesity who frequently have complex medical and behavioral health care needs. Specifically, we discuss the use of newer AOMs in these complex patients.

Methods

This review details an approach to the care of the child and adolescent with obesity using AOMs. A shared decision-making process is presented in which the provider and the patient and family collaborate on care. Management of medical and behavioral components of the disease of obesity in the child are discussed.

Results

Early aggressive treatment is recommended, starting with an assessment of associated medical and behavioral complications, weight promoting medications, use of AOMs and ongoing care. Intensive behavioral therapy is foundational to treatment, but not a specific treatment. Patients and families deserve education on expected outcomes with each therapeutic option.

Conclusions

The use of new AOMs in children and adolescents has changed expected clinical outcomes in the field of pediatric obesity management. Clinically significant improvement in obesity status occurs when AOMs are used early and aggressively. Ongoing, chronic care is the model for optimizing outcomes using a shared decision-making between provider and patient/family. Depending on the experience and comfort level of the primary care practitioner, referral to an obesity medicine specialist may be appropriate, particularly when obesity related co-morbidities are present and pharmacotherapy and metabolic and bariatric surgery are considerations.

Increased growth hormone secretagogue receptor-1a (GHSR-1a) in hypothalamus during olanzapine treatment in rats

Weight gain is the one of the most important factors which increases global burden of psychiatric disorder. Second-generation antipsychotics, olanzapine (Olz) and valproic acid (Vpa) in particular, are held responsible for weight gain. However, it is still uncertain how these drugs cause this. Thus, the rats selected for the experiment were randomly divided into 3 groups. The 1st group received only 0.5 ml saline solution intraperitoneally (n = 20, control group); the second group was given 200 mg / kg Vpa intraperitoneally (n = 20, Vpa group) and 2 mg / kg Olz was given intraperitoneally to the 3rd group (n = 20, Olz group) between 8 and 10 am for 30 days. We examined serum leptin, adiponectin, resistin, TNF-α, IL-6, ghrelin level and, the amount of ghrelin secreting cells in the stomach and growth hormone secretagogue receptor-1a (GHSR-1a, ghrelin receptor) expression in the hypothalamus. The hypothalamic GHS-1a receptor index was significantly higher in the Olz group compared with the control group and Vpa group (p = 0.036 and p = 0.016 respectively). Ghrelin immune positive cell index in stomach was statistically significantly lower in the Vpa group compared with the control and Olz groups (p = 0.028 and p = 0.013 respectively) There was no difference between the groups in terms of serum leptin, resistin, IL-6 and ghrelin levels. In the Vpa group, a statistically significant increase was found in serum adiponectin level compared with both the control group and the Olz group (p = 0009 and p = 0024 respectively) and, significant decrease was found in serum TNF-α level compared to Olz group (p = 0007). In conclusion, we found that the main cause of weight gain in Olz use was the increase in the number of hypothalamic ghrelin receptors. Investigating the mechanism by which Olz increases the number of ghrelin receptors may help to develop effective treatment strategies in preventing obesity in psychiatric patients.

Crosstalk between Schizophrenia and Metabolic Syndrome: The Role of Oxytocinergic Dysfunction

The high prevalence of metabolic syndrome in persons with schizophrenia has spurred investigational efforts to study the mechanism beneath its pathophysiology. Early psychosis dysfunction is present across multiple organ systems. On this account, schizophrenia may be a multisystem disorder in which one organ system is predominantly affected and where other organ systems are also concurrently involved. Growing evidence of the overlapping neurobiological profiles of metabolic risk factors and psychiatric symptoms, such as an association with cognitive dysfunction, altered autonomic nervous system regulation, desynchrony in the resting-state default mode network, and shared genetic liability, suggest that metabolic syndrome and schizophrenia are connected via common pathways that are central to schizophrenia pathogenesis, which may be underpinned by oxytocin system dysfunction. Oxytocin, a hormone that involves in the mechanisms of food intake and metabolic homeostasis, may partly explain this piece of the puzzle in the mechanism underlying this association. Given its prosocial and anorexigenic properties, oxytocin has been administered intranasally to investigate its therapeutic potential in schizophrenia and obesity. Although the pathophysiology and mechanisms of oxytocinergic dysfunction in metabolic syndrome and schizophrenia are both complex and it is still too early to draw a conclusion upon, oxytocinergic dysfunction may yield a new mechanistic insight into schizophrenia pathogenesis and treatment.

Metabolic syndrome following a first episode of psychosis: results of a 1-year longitudinal study conducted in metropolitan Lisbon, Portugal

Objective

We aimed to assess the prevalence and course of metabolic syndrome (MetS) and the associated metabolic parameters during the year following a first episode pf psychosis (FEP).

Methods

We performed a 1-year longitudinal observation of 60 patients who experienced FEP. MetS was defined using the modified definition of the National Cholesterol Education Program Adult Treatment Panel III. We assessed the metabolic parameters and socio-demographic and psychopathological data for the participants.

Results

The mean age of the participants was 27.1 years, and 33.3% of them were women. There was an increase in the prevalence of MetS from 6.7% to 11.7% during the year following the baseline assessment during the year following the baseline assessment (p = 0.250). There were also significant increases in the prevalences of abnormal triglyceride concentration, waist circumference, and high-density lipoprotein (HDL)-cholesterol concentration during this period. In addition, there was a considerable worsening of the metabolic profile of the participants. No baseline parameters were identified to be predictors of MetS over the 1-year follow-up period.

Conclusions

We can conclude that metabolic abnormalities are common in patients with FEP and that these rapidly worsen during the first year following the diagnosis of FEP. Studies on interventions are needed to reduce metabolic risk to cardiovascular diseases following the FEP.

Understanding the Effects of Antipsychotics on Appetite Control

Antipsychotic drugs (APDs) represent a cornerstone in the treatment of schizophrenia and other psychoses. The effectiveness of the first generation (typical) APDs are hampered by so-called extrapyramidal side effects, and they have gradually been replaced by second (atypical) and third-generation APDs, with less extrapyramidal side effects and, in some cases, improved efficacy. However, the use of many of the current APDs has been limited due to their propensity to stimulate appetite, weight gain, and increased risk for developing type 2 diabetes and cardiovascular disease in this patient group. The mechanisms behind the appetite-stimulating effects of the various APDs are not fully elucidated, partly because their diverse receptor binding profiles may affect different downstream pathways. It is critical to identify the molecular mechanisms underlying drug-induced hyperphagia, both because this may lead to the development of new APDs, with lower appetite-stimulating effects but also because such insight may provide new knowledge about appetite regulation in general. Hence, in this review, we discuss the receptor binding profile of various APDs in relation to the potential mechanisms by which they affect appetite.

Dietary Consumption Among Youth with Antipsychotic-Induced Weight Gain and Changes Following Healthy Lifestyle Education

Background: Youth treated with antipsychotic medications are high risk for weight gain, increased lipids/glucose, and development of metabolic syndrome. Little is known about the dietary intake/nutritional adequacy in this vulnerable population, and effect on weight gain. This secondary data analysis describes the baseline intake and changes in diet after receiving healthy lifestyle education/counseling over 6 months, in a sample of youth with antipsychotic-induced weight gain. Methods: The U.S. Department of Agriculture (USDA) Automated Multiple-Pass Method 24-hour dietary recall was administered to 117 youth at baseline, 3 months, and 6 months. Parent/child received personalized healthy lifestyle education sessions over 6 months. Baseline intake was compared with the USDA Recommended Daily Allowance using independent samples t-tests. Individual dietary covariates were examined for change over 6 months using longitudinal linear mixed modeling. Influence of each on body mass index (BMI) z-score change was tested in a pooled group analysis and then compared by treatment group. Results: Pooled analysis revealed baseline consumption high in carbohydrates, fat, protein, sugar, and refined grains, while low in fruit/vegetables, whole grains, fiber, and water. Change over 6 months demonstrated a statistically significant decrease in daily calories (p = 0.002), carbohydrates (p = 0.003), fat (p = 0.012), protein (p = 0.025), sugar (p = 0.008), refined grains (p = 0.008), total dairy (p = 0.049), and cheese (p = 0.027). Small increases in fruits/vegetables were not statistically significant, although the Healthy Eating Index subscores for total vegetables (p = 0.013) and dark green/orange vegetables (p = 0.034) were. No dietary covariates were predictors of change in BMI z-score. Nondietary predictors were parent weight/BMI and treatment group, with the metformin and switch groups experiencing significant decreases in BMI z-score. Conclusions: Further pediatric studies are necessary to assess the effects of antipsychotic medications on dietary intake, and test efficacy of healthy lifestyle interventions on change in nutrition. The relationship of nutrition to cardiometabolic health in this population must be further investigated. Clinical Trial Registration number: NCT02877823.

Gut microbiota: An intermediary between metabolic syndrome and cognitive deficits in schizophrenia

Gut microbiome interacts with the central nervous system tract through the gut-brain axis. Such communication involves neuronal, endocrine, and immunological mechanisms, which allows for the microbiota to affect and respond to various behaviors and psychiatric conditions. In addition, the use of atypical antipsychotic drugs (AAPDs) may interact with and even change the abundance of microbiome to potentially cause adverse effects or aggravate the disorders inherent in the disease. The regulate effects of gut microbiome has been described in several psychiatric disorders including anxiety and depression, but only a few reports have discussed the role of microbiota in AAPDs-induced Metabolic syndrome (MetS) and cognitive disorders. The following review systematically summarizes current knowledge about the gut microbiota in behavior and psychiatric illness, with the emphasis of an important role of the microbiome in the metabolism of schizophrenia and the potential for AAPDs to change the gut microbiota to promote adverse events. Prebiotics and probiotics are microbiota-management tools with documented efficacy for metabolic disturbances and cognitive deficits. Novel therapies for targeting microbiota for alleviating AAPDs-induced adverse effects are also under fast development.

Effect of liraglutide on neural and peripheral markers of metabolic function during antipsychotic treatment in rats

BACKGROUND

Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that prevents metabolic side effects of the antipsychotic drugs (APDs) olanzapine and clozapine through unknown mechanisms.

AIM

This study aimed to investigate the effect of chronic APD and liraglutide co-treatment on key neural and peripheral metabolic signals, and acute liraglutide co-treatment on clozapine-induced hyperglycaemia.

METHODS

In study 1, rats were administered olanzapine (2 mg/kg), clozapine (12 mg/kg), liraglutide (0.2 mg/kg), olanzapine + liraglutide co-treatment, clozapine + liraglutide co-treatment or vehicle for six weeks. Feeding efficiency was examined weekly. Examination of brain tissue (dorsal vagal complex (DVC) and mediobasal hypothalamus (MBH)), plasma metabolic hormones and peripheral (liver and kidney) cellular metabolism and oxidative stress was conducted. In study 2, rats were administered a single dose of clozapine (12 mg/kg), liraglutide (0.4 mg/kg), clozapine + liraglutide co-treatment or vehicle. Glucose tolerance and plasma hormone levels were assessed.

RESULTS

Liraglutide co-treatment prevented the time-dependent increase in feeding efficiency caused by olanzapine, which plateaued by six weeks. There was no effect of chronic treatment on melanocortinergic, GABAergic, glutamatergic or endocannabionoid markers in the MBH or DVC. Peripheral hormones and cellular metabolic markers were unaltered by chronic APD treatment. Acute liraglutide co-treatment was unable to prevent clozapine-induced hyperglycaemia, but it did alter catecholamine levels.

CONCLUSION

The unexpected lack of change to central and peripheral markers following chronic treatment, despite the presence of weight gain, may reflect adaptive mechanisms. Further studies examining alterations across different time points are required to continue to elucidate the mechanisms underlying the benefits of liraglutide on APD-induced metabolic side effects.

Antipsychotics inhibit the mitochondrial bioenergetics of pancreatic beta cells isolated from CD1 mice

Antipsychotics (APs) are widely used medications with reported diabetogenic side effects. This study investigated the effect of commonly used APs, namely chlorpromazine (CPZ), haloperidol (HAL) and clozapine, on the bioenergetics of male CD1 mice isolated pancreatic beta cells as an underlying mechanism of their diabetogenic effects. The effect of APs on Alamar blue reduction, adenosine triphosphate (ATP) production and glucose-stimulated insulin secretion (GSIS) of isolated beta cells was evaluated. Then, the effects of APs on the activities of mitochondrial complexes and their common coding genes expression, oxygen consumption rate (OCR), mitochondrial membrane potential (MMP) and lactate production were investigated. The effects of APs on the mitochondrial membrane fluidity (MMF) and mitochondrial membrane fatty acid composition were also examined. Results showed that the tested APs significantly decreased cellular ATP production and GSIS of the beta cells. The APs significantly inhibited the activities of mitochondrial complexes and their coding gene expression, MMP and OCR of the treated cells, with a parallel increase in lactate production to different extents with the different APs. CPZ and HAL showed increased MMF and mitochondrial membrane polyunsaturated fatty acid content. In conclusion, the tested APs-induced mitochondrial disruption can play a role in their diabetogenic side effect.

Metabolic profile of methylazoxymethanol model of schizophrenia in rats and effects of three antipsychotics in long-acting formulation

Mortality in psychiatric patients with severe mental illnesses reaches a 2-3 times higher mortality rate compared to the general population, primarily due to somatic comorbidities. A high prevalence of cardiovascular morbidity can be attributed to the adverse metabolic effects of atypical antipsychotics (atypical APs), but also to metabolic dysregulation present in drug-naïve patients. The metabolic aspects of neurodevelopmental schizophrenia-like models are understudied. This study evaluated the metabolic phenotype of a methylazoxymethanol (MAM) schizophrenia-like model together with the metabolic effects of three APs [olanzapine (OLA), risperidone (RIS) and haloperidol (HAL)] administered via long-acting formulations for 8 weeks in female rats. Body weight, feed efficiency, serum lipid profile, gastrointestinal and adipose tissue-derived hormones (leptin, ghrelin, glucagon and glucagon-like peptide 1) were determined. The lipid profile was assessed in APs-naïve MAM and control cohorts of both sexes. Body weight was not altered by the MAM model, though cumulative food intake and feed efficiency was lowered in the MAM compared to CTR animals. The effect of the APs was also present; body weight gain was increased by OLA and RIS, while OLA induced lower weight gain in the MAM rats. Further, the MAM model showed lower abdominal adiposity, while OLA increased it. Serum lipid profile revealed MAM model-induced alterations in both sexes; total, HDL and LDL cholesterol levels were increased. The MAM model did not exert significant alterations in hormonal parameters except for elevation in leptin level. The results support intrinsic metabolic dysregulation in the MAM model in both sexes, but the MAM model did not manifest higher sensitivity to metabolic effects induced by antipsychotic treatment.

Role of TRPV1/TRPV3 channels in olanzapine-induced metabolic alteration: Possible involvement in hypothalamic energy-sensing, appetite regulation, inflammation and mesolimbic pathway

Atypical antipsychotics (AAPs) have the tendency of inducing severe metabolic alterations like obesity, diabetes mellitus, insulin resistance, dyslipidemia and cardiovascular complications. These alterations have been attributed to altered hypothalamic appetite regulation, energy sensing, insulin/leptin signaling, inflammatory reactions and active reward anticipation. Line of evidence suggests that transient receptor potential vanilloid type 1 and 3 (TRPV1 and TRPV3) channels are emerging targets in treatment of obesity, diabetes mellitus and could modulate feed intake. The present study was aimed to investigate the putative role TRPV1/TRPV3 in olanzapine-induced metabolic alterations in mice. Female BALB/c mice were treated with olanzapine for six weeks to induce metabolic alterations. Non-selective TRPV1/TRPV3 antagonist (ruthenium red) and selective TRPV1 (capsazepine) and TRPV3 antagonists (2,2-diphenyltetrahydrofuran or DPTHF) were used to investigate the involvement of TRPV1/TRPV3 in chronic olanzapine-induced metabolic alterations. These metabolic alterations were differentially reversed by ruthenium red and capsazepine, while DPTHF didn't show any significant effect. Olanzapine treatment also altered the mRNA expression of hypothalamic appetite-regulating and nutrient-sensing factors, inflammatory genes and TRPV1/TRPV3, which were reversed with ruthenium red and capsazepine treatment. Furthermore, olanzapine treatment also increased expression of TRPV1/TRPV3 in nucleus accumbens (NAc), TRPV3 expression in ventral tegmental area (VTA), which were reversed by the respective antagonists. However, DPTHF treatment showed reduced feed intake in olanzapine treated mice, which might be due to TRPV3 specific antagonism and reduced hedonic feed intake. In conclusion, our results suggested the putative role TRPV1 in hypothalamic dysregulations and TRPV3 in the mesolimbic pathway; both regulate feeding in olanzapine treated mice.

Nutritional status, food choices, barriers and facilitators to healthy nutrition in pregnant women with severe mental illness: a mixed methods approach

BACKGROUND

Although widely acknowledged that adequate maternal nutrition is important for mother and baby, limited research has focussed on women with severe mental illnesses (SMI) in pregnancy. The present study reports on nutritional factors and food choices and investigates barriers and facilitators to healthy nutritional choices by pregnant women with SMI.

METHODS

A prospective mixed method study was undertaken of 38 pregnant women with SMI, including a cross-sectional survey, a food frequency questionnaire and 12 postnatal qualitative interviews, with integrated analysis of all data.

RESULTS

Elevated rates of obesity (35%) were found, with 82% of women having above the recommended gestational weight gain. Despite perceived knowledge, 32% of women did not meet any of the Five Food Group serving recommendations for pregnancy and consumed above-recommended levels for processed (19%) and sugar snacks (51%). Thematic analysis identified four main barriers: a discrepancy between knowledge and action, food cravings, mental health, and physical health. During pregnancy, food cravings were reported in 66% of women, psychological distress in 71% and physical distress in 37%. Screening identified 19% with potential eating disordered behaviours. Despite the challenges, several facilitators were identified and covered three themes: access to a dietitian, information delivery and support, and comprehensive care.

DISCUSSION

Women with SMI in pregnancy struggle with issues of obesity, gestational weight gain, food cravings and possible eating disorder behaviours. They have additional challenges when pregnant, with management of their mental health and physical health having a direct impact. Interventional strategies in this population should incorporate findings from this research.

Berberine attenuated olanzapine-induced metabolic alterations in mice: Targeting transient receptor potential vanilloid type 1 and 3 channels

Transient receptor potential vanilloid type 1 (TRPV1) channels are emerging therapeutic targets for metabolic disorders. Berberine, which is a modulator of TRPV1, has proven antiobesity and antidiabetic potentials. The present study was aimed to investigate the protective effects of berberine in olanzapine-induced alterations in hypothalamic appetite control, inflammation and metabolic aberrations in mice targeting TRPV1 channels. Female BALB/c mice (18-23 g) were treated with olanzapine (6 mg/kg, p.o.) for six weeks to induce metabolic alterations, while berberine (100 and 200 mg/kg, p.o.) and metformin (100 mg/kg, p.o) were used as test and standard interventions respectively. Weekly assessment of feed-water intake, body temperature and body weight was done, while locomotion was measured at the end of week 1 and 6. Serum glucose and lipid profile were assessed by biochemical methods, while other serum biomarkers were assessed by ELISA. qPCR was used to quantify the mRNA expression in the hypothalamus. Olanzapine treatment significantly increased the feed intake, weight gain, adiposity index, while reduced body temperature and locomotor activity which were reversed by berberine treatment. Berberine treatment reduced serum ghrelin and leptin levels as well decrease in hypothalamic mRNA expression of orexigenic neuropeptides, inflammatory markers and ghrelin receptor in olanzapine-treated mice. Olanzapine treatment increased expression of TRPV1/TRPV3 in the hypothalamus which was significantly decreased by berberine treatment. Our results suggest that berberine, by TRPV1/TRPV3 modulation, attenuated the olanzapine-induced metabolic alterations in mice. Hence berberine supplementation in psychiatric patients could be a preventive approach to reduce the metabolic adverse effects of antipsychotics.

Relationship between metabolic syndrome and acylated/desacylated ghrelin ratio in patients with schizophrenia under olanzapine medication

BACKGROUND

Ghrelin is a peptide hormone that mediates glucose homeostasis and lipid metabolism. Acylated ghrelin (AG) and desacylated ghrelin (DAG) are the two main forms of ghrelin, which have opposing roles in energy homeostasis. The AG/DAG ratio has been proposed to be associated with metabolic syndrome (MetS) in the general population. This study compared the relationships between MetS and ghrelin parameters in patients with schizophrenia.

METHODS

Patients diagnosed with schizophrenia and under olanzapine monotherapy were recruited. Fasting blood samples were collected for the analyses of metabolic and ghrelin parameters. The serum levels of total ghrelin and AG were measured by enzyme-linked immunosorbent assay kits. DAG level was calculated by subtracting the AG level from the total ghrelin level.

RESULTS

We recruited 151 subjects with schizophrenia, and classified them into those with MetS (n = 41) and those without MetS (n = 110). Subjects with MetS had a significantly higher AG/DAG ratio, as well as lower total ghrelin and DAG levels. There were no sex differences in ghrelin parameters. The AG/DAG ratio was significantly and positively correlated with weight, body mass index, waist circumference, insulin level, homeostasis model assessment of insulin resistance and number of MetS components. Multiple linear regression analysis indicated that the number of MetS components remained significantly associated with the AG/DAG ratio.

CONCLUSIONS

Our results revealed that lower AG/DAG ratios were associated with better metabolic profiles in olanzapine-treated patients with schizophrenia. These observations suggest that the balance between AG and DAG plays a crucial role in the metabolic homeostasis among patients with schizophrenia.

The Role of Adiponectin in the Pathogenesis of Metabolic Disturbances in Patients With Schizophrenia

Antipsychotic-induced metabolic disturbance is a common adverse event occurring in patients treated with antipsychotic drugs. The mechanisms underlying metabolic dysregulation are complex, involving various neurochemical and hormonal systems, the interaction of genetic and lifestyle risk factors, and the antipsychotic drug prescribed. Recently, there has been increasing interest in the relationship between antipsychotic-induced metabolic disturbances and body weight regulatory hormones such as adiponectin. Adiponectin, an adipocyte-derived protein related to insulin sensitivity, weight gain, and anti-inflammation, has attracted great attention because of its potential role of being a biomarker to predict cardiovascular and metabolic diseases. Previous studies regarding the effects of antipsychotics on blood adiponectin levels have shown controversial results. Several factors might contribute to those inconsistent results, including different antipsychotic drugs, duration of antipsychotic exposure, age, sex, and ethnicity. Here we summarize the existing evidence on the link between blood adiponectin levels and metabolic disturbances related to antipsychotic drugs in patients with schizophrenia. We further discuss the effects of individual antipsychotics, patients' gender, ethnicity, age, and treatment duration on those relationships. We propose that olanzapine and clozapine might have a time-dependent biphasic effect on blood adiponectin levels in patients with schizophrenia.

High prevalence of prediabetes and metabolic abnormalities in overweight or obese schizophrenia patients treated with clozapine or olanzapine

OBJECTIVE

To assess the prevalence of prediabetes and metabolic abnormalities among overweight or obese clozapine- or olanzapine-treated schizophrenia patients, and to identify characteristics of the schizophrenia group with prediabetes.

METHODS

A cross-sectional study assessing the presence of prediabetes and metabolic abnormalities in schizophrenia clozapine- or olanzapine-treated patients with a body mass index (BMI) ≥27 kg/m2. Procedures were part of the screening process for a randomized, placebo-controlled trial evaluating liraglutide vs placebo for improving glucose tolerance. For comparison, an age-, sex-, and BMI-matched healthy control group without psychiatric illness and prediabetes was included. Prediabetes was defined as elevated fasting plasma glucose and/or impaired glucose tolerance and/or elevated glycated hemoglobin A1c.

RESULTS

Among 145 schizophrenia patients (age = 42.1 years; males = 59.3%) on clozapine or olanzapine (clozapine/olanzapine/both: 73.8%/24.1%/2.1%), prediabetes was present in 69.7% (101 out of 145). While schizophrenia patients with and without prediabetes did not differ regarding demographic, illness, or antipsychotic treatment variables, metabolic abnormalities (waist circumference: 116.7±13.7 vs 110.1±13.6 cm, P = 0.007; triglycerides: 2.3±1.4 vs 1.6±0.9 mmol/L, P = 0.0004) and metabolic syndrome (76.2% vs 40.9%, P<0.0001) were significantly more pronounced in schizophrenia patients with vs without prediabetes. The age-, sex-, and BMI-matched healthy controls had significantly better glucose tolerance compared to both groups of patients with schizophrenia. The healthy controls also had higher levels of high-density lipoprotein compared to patients with schizophrenia and prediabetes.

CONCLUSION

Prediabetes and metabolic abnormalities were highly prevalent among the clozapine- and olanzapine-treated patients with schizophrenia, putting these patients at great risk for later type 2 diabetes and cardiovascular disease. These results stress the importance of identifying and adequately treating prediabetes and metabolic abnormalities among clozapine- and olanzapine-treated patients with schizophrenia.

Pharmacogenetic Correlates of Antipsychotic-Induced Weight Gain in the Chinese Population

Antipsychotic-induced weight gain (AIWG) is a common adverse effect of this treatment, particularly with second-generation antipsychotics, and it is a major health problem around the world. We aimed to review the progress of pharmacogenetic studies on AIWG in the Chinese population to compare the results for Chinese with other ethnic populations, identify the limitations and problems of current studies, and provide future research directions in China. Both English and Chinese electronic databases were searched to identify eligible studies. We determined that > 25 single-nucleotide polymorphisms in 19 genes have been investigated in association with AIWG in Chinese patients over the past few decades. HTR2C rs3813929 is the most frequently studied single-nucleotide polymorphism, and it seems to be the most strongly associated with AIWG in the Chinese population. However, many genes that have been reported to be associated with AIWG in other ethnic populations have not been included in Chinese studies. To explain the pharmacogenetic reasons for AIWG in the Chinese population, genome-wide association studies and multiple-center, standard, unified, and large samples are needed.

Olanzapine - Focus on the Cardiometabolic Side Effects

In this article, we review the recent findings concerning weight gain, diabetes mellitus (DM), hyperlipidemia, cardiovascular side effects in patients receiving olanzapine. It will consider the OLZ is associated with an increase in metabolic syndrome or cardiovascular events, and knowledge of these risks is crucial for further monitoring of patients with OLZ-treatment. Although it is one of the most commonly prescribed and effective AATPs, olanzapine causes the most weight gain and metabolic impairments in humans. As noted with glucose abnormalities and antipsychotics, olanzapine has the greatest propensity for causing proatherogenic hyperlipidemia. The mechanism of dyslipidemia with OLZ is poorly understood, but OLZ has been shown to increase lipogenesis, reduce lipolysis, and enhance the antilipolytic effects of insulin in adipocytes. Olanzapine can induce cardiomyopathy in selected patients.

Taken together, all mentioned data indicate that interventions aimed at the amelioration of obesity and cardiovascular illness need to be as multipronged and complex as the contributing psychosocial, behavioural, and biological factors that make obesity and cardiovascular illness more likely in patients with severe mental illness, including schizophrenia.

Aripiprazole-induced adverse metabolic alterations in polyI:C neurodevelopmental model of schizophrenia in rats

Schizophrenia appears to be linked to higher incidence of metabolic syndrome even in the absence of antipsychotic treatment. Atypical antipsychotics substantially differ in their propensity to induce metabolic alterations. Aripiprazole is considered to represent an antipsychotic drug with low risk of metabolic syndrome development. The aim of this study was to evaluate metabolic phenotype of neurodevelopmental polyI:C rat model and assess metabolic effects of chronic aripiprazole treatment with regard to complex neuroendocrine regulations of energy homeostasis. Polyinosinic:polycytidylic acid (polyI:C) was administered subcutaneously at a dose of 8 mg/kg in 10 ml on gestational day 15 to female Wistar rats. For this study 20 polyI:C and 20 control adult male offspring were used, randomly divided into 2 groups per 10 animals for chronic aripiprazole treatment and vehicle. Aripiprazole (5 mg/kg, dissolved tablets, ABILIFY^®) was administered once daily via oral gavage for a month. Altered lipid profile in polyI:C model was observed and a trend towards different dynamics of weight gain in polyI:C rats was noted in the absence of significant antipsychotic treatment effect. PolyI:C model was not associated with changes in other parameters i.e. adipokines, gastrointestinal hormones and cytokines levels. Aripiprazole did not influence body weight but it induced alterations in neurohumoral regulations. Leptin and GLP-1 serum levels were significantly reduced, while ghrelin level was elevated. Furthermore aripiprazole decreased serum levels of pro-inflammatory cytokines. Our data indicate dysregulation of adipokines and gastrointestinal hormones present after chronic treatment with aripiprazole which is considered metabolically neutral in the polyI:C model of schizophrenia.

Excess mortality in people with mental illness: findings from a Northern Italy psychiatric case register

PURPOSE

People with mental disorders show mortality rates up to 22.2 times higher than that of the general population. In spite of progressive increase in life expectancy observed in the general population, the mortality gap of people suffering from mental health problems has gradually widened. The aim of this paper was to study mortality rates in people suffering from mental illness in a cohort of people (16,981 subjects) in the local mental health register of the province of Modena during the decade 2006-2015.

METHODS

Standardized Mortality Ratios (SMRs) were calculated to compare the mortality of people with mental disorders to the mortality of people living in the province of Modena and the excess of mortality was studied in relation to the following variables: gender, age group, diagnosis and causes of death. In addition, Poisson regression analysis was performed to study the association between patient characteristics and mortality.

RESULTS

An overall excess mortality of 80% was found in subjects under the care of mental health services as compared to the reference population (SMR = 1.8, 95% CI 1.7-1.9). Subjects in the 15-44 year group presented the highest SMR (9.2, 95% CI 6.9-11.4). The most prevalent cause of death was cancer (28.1% of deaths). At the Poisson regression, the diagnosis "Substance abuse and dependence" showed the highest relative risk (RR) (4.00). Moreover, being male, single, unemployed and with a lower qualification was associated with higher RRs.

CONCLUSIONS

Our study confirms that subjects with mental illness have higher SMR. Noteworthy, the overall higher risk of mortality was observed in the younger age group.

Decreased 5-HT2cR and GHSR1a interaction in antipsychotic drug-induced obesity

Second generation antipsychotics (SGAs), notably atypical antipsychotics including olanzapine, clozapine and risperidone, can cause weight gain and obesity side effects. Antagonism of serotonin 2c receptors (5-HT2cR) and activation of ghrelin receptor type 1a (GHSR1a) signalling have been identified as a main cause of SGA induced obesity. Here we review the pivotal regulatory role of the 5-HT2cR in ghrelin-mediated appetite signalling. The 5-HT2cR dimerizes with GHSR1a to inhibit orexigenic signalling, while 5-HT2cR antagonism reduces dimerization and increases GHSR1a-induced food intake. Dimerization is specific to the unedited 5-HT2cR isoform. 5-HT2cR antagonism by SGAs may disrupt the normal inhibitory tone on the GHSR1a, increasing orexigenic signalling. The 5-HT2cR and its interaction with the GHSR1a could serve as the basis for discovering novel approaches to preventing and treating SGA-induced obesity.

Is Obesity in Young People With Psychosis a Foregone Conclusion? Markedly Excessive Energy Intake Is Evident Soon After Antipsychotic Initiation

Introduction: Antipsychotic medication (APM) initiation is associated with rapid and substantial weight-gain and high rates of obesity. Obesity leads to premature onset of cardiometabolic diseases and contributes to the 15-20 year shortfall in life expectancy in those experiencing severe mental illness. Dietary energy intake excess is critical to weight management but is yet to be quantified in youth with first episode psychosis (FEP) receiving APM. This study aimed to describe the degree of energy overconsumption and the food sources contributing to this in youth with FEP. Materials and Methods: People aged 15-30 years with FEP receiving APM completed diet histories through qualified dietitians to assess energy imbalance and food sources. Outcome measures were: (i) energy balance; and (ii) intake of core and discretionary foods. Results: Participants (n = 93) were aged 15-29 years (mean = 21.4 ± 2.9 years) and exposed to APMs for a median for 8 months (Interquartile Range (IQR) 11 months). Energy balance was exceeded by 26%, by a median 1,837 kJ per day (IQR 5,365 kJ). APM polypharmacy and olanzapine were linked to larger excesses in dietary energy intake. The greatest contributors to energy intake were refined grain foods (33%) and discretionary foods (31%). Conclusion: Young people with FEP receiving APMs appear to have markedly excessive energy consumption, likely contributing to rapid weight-gain, and thereby seeding future poor physical health. Larger, prospective studies are needed to gain a greater understanding of dietary intake, and its effects on health, in people with FEP.

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.

Neural circuits of eating behaviour: Opportunities for therapeutic development

Understanding of the neural and physiological substrates of hunger and satiety has increased rapidly over the last three decades, and pharmacological targets have already been identified for the treatment of obesity that has moved from pre-clinical screening to therapies approved by regulatory authorities. Initially, this review describes the way in which physiological signals of energy availability interact with hedonic and rewarding properties of food to modulate the neural circuitry that supports eating behaviour. This is followed by a brief account of current and promising targets for drug development and a review of the wide range of preclinical paradigms that model important influences on human eating behaviour, and can be used to guide early stages of the drug development process.

Ghrelin Serum Concentrations Are Associated with Treatment Response During Lithium Augmentation of Antidepressants

BACKGROUND

Lithium augmentation of antidepressants is an effective strategy in treatment-resistant depression. The proteohormone ghrelin is thought to be involved in the pathophysiology of depression. The purpose of this study was to investigate the association of treatment response with the course of ghrelin levels during lithium augmentation.

METHOD

Ghrelin serum concentrations and severity of depression were measured in 85 acute depressive patients before and after 4 weeks of lithium augmentation.

RESULTS

In a linear mixed model analysis, we found a significant effect of response*time interaction (F1.81=9.48; P=.0028): under treatment, ghrelin levels increased in nonresponders and slightly decreased in responders to lithium augmentation. The covariate female gender had a significant positive effect (F1.83=4.69; P=.033), whereas time, response, appetite, and body mass index (kg/m2) did not show any significant effect on ghrelin levels (P>.05).

CONCLUSION

This is the first study showing that the course of ghrelin levels separates responders and nonresponders to lithium augmentation. Present results support the hypothesis that ghrelin serum concentrations might be involved in response to pharmacological treatment of depression.

Metabolic side effects induced by olanzapine treatment are neutralized by CB1 receptor antagonist compounds co-administration in female rats

Weight gain is an important side effect of most atypical antipsychotic drugs such as olanzapine. Moreover, although many animal models with metabolic side effects have been well defined, the interaction with other pathways has to be considered. The endocannabinoid system and the CB1 receptor (CB1R) are among the most promising central and peripheral targets involved in weight and energy balance. In this study we developed a rat model based 15-days treatment with olanzapine that shows weight gain and an alteration of the blood parameters involved in the regulation of energy balance and glucose metabolism. Consequently, we analysed whether, and by which mechanism, a co-treatment with the novel CB1R neutral antagonist NESS06SM, could attenuate the adverse metabolic effects of olanzapine compared to the reference CB1R inverse agonist rimonabant. Our results showed alterations of the cannabinoid markers in the nucleus accumbens and of orexigenic/anorexigenic markers in the hypothalamus of female rats treated with olanzapine. These molecular modifications could explain the excessive food intake and the resulting weight gain. Moreover, we confirmed that a co-treatment with CB1R antagonist/inverse agonist compounds decreased food intake and weight increment and restored all blood parameters, without altering the positive effects of olanzapine on behaviour. Furthermore, rimonabant and NESS06SM restored the metabolic enzymes in the liver and fat tissue altered by olanzapine. Therefore, CB1 receptor antagonist/inverse agonist compounds could be good candidate agents for the treatment of weight gain induced by olanzapine.

Depot risperidone-induced adverse metabolic alterations in female rats

Atypical antipsychotics are associated with adverse metabolic effects including weight gain, increased adiposity, dyslipidaemia, alterations in glucose metabolism and insulin resistance. Increasing evidence suggests that metabolic dysregulation precedes weight gain development. The aim of this study was to evaluate alterations in adipokines, hormones and basic serum biochemical parameters induced by chronic treatment with depot risperidone at two doses (20 and 40 mg/kg) in female Sprague-Dawley rats. Dose-dependent metabolic alterations induced by risperidone after 6 weeks of treatment were revealed. Concomitant to weight gain and increased liver weight, an adverse lipid profile with an elevated triglyceride level was observed in the high exposure group, administered a 40 mg/kg dose repeatedly, while the low dose exposure group, administered a 20 mg/kg dose, developed weight gain without alterations in the lipid profile and adipokine levels. An initial peak in leptin serum level after the higher dose was observed in the absence of weight gain. This finding may indicate that the metabolic alterations observed in this study are not consequent to body weight gain. Taken together, these data may support the primary effects of atypical antipsychotics on peripheral tissues.

Olanzapine-depot administration induces time-dependent changes in adipose tissue endocrine function in rats

OBJECTIVE

Metabolic adverse effects of atypical antipsychotics (AAP) contribute significantly to increased risk of cardiovascular morbidity and mortality in patients suffering from schizophrenia. Extensive preclinical research has addressed this issue over the past years, though mechanisms underlying these adverse effects of AAP are still not understood completely. Recently, attention is drawn towards the role of adipose tissue metabolism and neurohormonal regulations.

METHODS

The aim of this study was to evaluate the time-dependent effects of olanzapine depot administration at clinically relevant dosing on the regulation of energy homeostasis, glucose and lipid metabolism, gastrointestinal and adipose tissue-derived hormones involved in energy balance regulations in female Sprague-Dawley rats. The study lasted 8 weeks and the markers were assayed at day 8, 15, 29, 43 and 57.

RESULTS

The results indicate that in the absence of hyperphagia, olanzapine chronic exposure induced weight gain from the beginning of the study. In the later time-point, increased adiposity was also observed. In the initial phase of the study, lipid profile was altered by an early increase in triglyceride level and highly elevated leptin level was observed. Clear bi-phasic time-dependent effect of olanzapine on leptin serum concentration was demonstrated. Olanzapine treatment did not lead to changes in serum levels of ghrelin, FGF-21 and pro-inflammatory markers IL-1a, IL-6 and TNF-α at any time-point of the study.

CONCLUSION

This study provides data suggesting early alteration in adipose tissue endocrine function as a factor involved in mechanisms underlying metabolic adverse effects of antipsychotics.

The atypical antipsychotic, olanzapine, potentiates ghrelin-induced receptor signaling: An in vitro study with cells expressing cloned human growth hormone secretagogue receptor

The growth hormone secretagogue receptor (GHS-R) belongs to Gαq-coupled G protein-coupled receptor (GPCR) that mediates growth hormone release, food intake, appetite, glucose metabolism and body composition. Ghrelin has been identified as an endogenous ligand for GHS-R, and it is the only orexigenic peptide found in the peripheral organs. Olanzapine, an atypical antipsychotic agent that binds to and inhibits the activation of GPCR for several neurotransmitters, has metabolic side effects such as excessive appetite and weight gain. Recently, studies have revealed that the orexigenic mechanism of olanzapine is mediated via GHS-R signaling, although the precise mechanisms have not been clarified. In this study, we investigated the effect of olanzapine on ghrelin-mediated GHS-R signaling by using an electrical impedance-based receptor biosensor assay system (CellKey™). Olanzapine at concentrations of 10(-7) and 10(-6)mol/L enhanced ghrelin-induced (10(-10)-10(-8)mol/L) GHS-R activation. A Ca(2+) imaging assay revealed that olanzapine (10(-7) and 10(-6)mol/L) enhanced ghrelin (10(-7) M)-induced GHS-R activity. In contrast, haloperidol (an antipsychotic agent) failed to enhance this ghrelin-mediated GHS-R activation, as demonstrated by both the CellKey™ and Ca(2+) imaging assays. Together, these results suggest that olanzapine, but not haloperidol, promotes appetite by enhancing ghrelin-mediated GHS-R signaling.

Modulation of triglyceride accumulation in adipocytes by psychopharmacological agents in vitro

Weight gain is a major problem during psychopharmacological treatment. Research has concentrated on the appetite inducing properties and mechanisms of these drugs in the central nervous system. The potential contribution of direct effects of drugs on metabolically relevant peripheral cells such as adipocytes is less well understood. We examined the influence of the antidepressant imipramine, the antipsychotic clozapine, and the mood stabilizer lithium on preadipocytes and adipocytes in vitro, using Simpson-Golabi-Behmel syndrome (SGBS) cells, an established human preadipocyte model. Parameters of cell differentiation and signaling, and cell metabolism were measured. We found significantly increased triglyceride accumulation in adipocytes after supplementation with imipramine and lithium at therapeutic concentrations, compared to non-supplemented control samples. However, gene expression levels of an early marker of adipogenesis, the peroxisome proliferator-activated receptor gamma (PPAR-γ) and a late marker of adipogenesis, the fatty acid binding protein 4 (FABP4), as well as expression of adiponectin (ADIPOQ) did not change significantly in the presence of these psychopharmacological agents. The results suggest a direct influence of imipramine and lithium but not clozapine on fat storage of adipocytes. The underlying mechanisms of fatty acid storage and adipocyte differentiation however remain to be elucidated.

Effect of extended olanzapine administration on POMC and neuropeptide Y mRNA levels in the male rat amygdala and hippocampus

BACKGROUND

Neuropeptides play an important role in various neural pathways, being able to control a wide spectrum of physiological responses. Neuropeptide Y (NPY) and proopiomelanocortin (POMC) functions are quite well studied, however little is known about their action at the level of limbic structures. The present work was focused on the expression of the aforementioned peptides in this brain structure of rats treated with olanzapine, a second generation neuroleptic drug. The detailed purpose of this experiment was the evaluation of potential relationships between chronic olanzapine administration and NPY and POMC mRNA expression in the amygdala and hippocampal formation.

METHODS

The studies were carried out on adult, male Sprague-Dawley rats that were divided into 2 groups: control and experimental animals treated with olanzapine (28 day-long intraperitoneal injection). All individuals were sacrificed under anaesthesia, then the amygdaloid complexes and hippocampi were excised. Total mRNA was isolated from homogenized samples of both structures and the RT-PCR method was used for estimation of NPY and POMC gene relative expression.

RESULTS

Prolonged olanzapine administration is reflected in qualitatively different changes in expression of NPY and POMC mRNA in the rat amygdala and hippocampus. Interestingly enough, olanzapine did not affect NPY expression, but significantly increased the POMC level in both examined regions.

CONCLUSIONS

Olanzapine can affect amygdalar and hippocampal neuronal populations by the modulation of neuropeptide activity. Importantly, it may suggest the existence of an alternative mode of its action. Undoubtedly this hypothetic regulatory mechanism requires further pharmacological and neurostructural study.

Effect of long-term olanzapine treatment on meal-induced insulin sensitization and on gastrointestinal peptides in female Sprague-Dawley rats

Meal-induced insulin sensitization (MIS), an endogenous adaptive mechanism is activated post-prandially. Reduced MIS leads to diabetes, but its activation improves insulin sensitivity. MIS is preserved to single olanzapine administration, therefore we aimed to investigate the chronic effect of olanzapine on fasted-state insulin sensitivity and on MIS in female Sprague-Dawley rats. Daily food and water intake, stool and urine production and body weight were determined. The MIS was characterized by a rapid insulin sensitivity test. Fasting hepatic and peripheral insulin sensitivity were determined by a hyperinsulinaemic euglycaemic glucose clamping supplemented with radiotracer technique. Fasted and post-prandial blood samples were obtained for plasma insulin, leptin, ghrelin, amylin, GLP-1, GIP, PYY and PP determination. Adiposity was characterized by weighing intra-abdominal and inguinal fat pads. Olanzapine caused hepatic insulin resistance and a reduced metabolic clearance rate of insulin, but the MIS retained its function. Body weight and adiposity were enhanced, but olanzapine failed to increase food intake. Fasting insulin and leptin were elevated and the post-prandial reduction in ghrelin level was inhibited by olanzapine.The MIS remained functionally intact after long-term olanzapine treatment. Altered insulin, leptin and ghrelin levels indicate olanzapine-induced metabolic derangements. Pharmacological activation of MIS could potentially be exploited to treat or prevent olanzapine-induced insulin resistance.

Effect of short and long-term treatment with antipsychotics on orexigenic/anorexigenic neuropeptides expression in the rat hypothalamus

Among numerous side effects of antipsychotic drugs (neuroleptics), one of the leading problems is a significant weight gain caused by disturbances in energy homeostasis. The hypothalamus is considered an important target for neuroleptics and contains some neuronal circuits responsible for food intake regulation, so we decided to study which hypothalamic signaling pathways connected with energy balance control are modified by antipsychotic drugs of different generations. We created an expression profile of different neuropeptides after single-dose and chronic neuroleptic administration. Experiments were carried out on adult male Sprague-Dawley rats injected intraperitoneally for 1 day or for 28 days by three neuroleptics: olanzapine, chlorpromazine and haloperidol. Hypothalami were isolated in order to perform PCR reactions and also whole brains were sliced for immunohistochemical analysis. We assessed the expression of orexigenic/anorexigenic neuropeptides and their receptors--neuropeptide Y (NPY), NPY receptor type 1 (Y1R), preproorexin (PPOX), orexin A, orexin receptor type 1 (OX1R) and 2 (OX2R), nucleobindin 2 (NUCB2), nesfatin-1, proopiomelanocortin (POMC), alpha-melanotropin (α-MSH) and melanocortin receptor type 4 (MC4R)--both on the mRNA and protein levels. We have shown that antipsychotics of different generations administered chronically have the ability to upregulate PPOX, orexin A and Y1R expression with little or no effect on orexigenic receptors (OX1R, OX2R) and NPY. Interestingly, antipsychotics also increased the level of some anorexigenic factors (POMC, α-MSH and MC4R), but at the same time strongly downregulated NUCB2 and nesfatin-1 signaling--a newly discovered neuropeptide known as a food-intake inhibiting factor. Our results may contribute to a better understanding of mechanisms responsible for antipsychotics' side effects. They also underline the complex nature of interactions between classical monoamine receptors and hypothalamic peptidergic pathways, which has potential clinical applications.

Differential effects of olanzapine and clozapine on plasma levels of adipocytokines and total ghrelin

Second-generation antipsychotics (SGAs) have been associated with an increased liability for weight gain and metabolic side effects. Among SGAs, clozapine and olanzapine had great liability to induce weight gain and metabolic adverse reactions. Leptin, adiponectin, and total ghrelin play important roles in energy homeostasis and are suggested to be biomarkers of metabolic disturbances. The purpose of the present study was to investigate the differential effects of antipsychotics (olanzapine and clozapine) on the levels of adipocytokines (leptin and adiponectin) and total ghrelin. Three hundred and thirty-three patients with schizophrenia under clozapine or olanzapine monotherapy were recruited. Control participants were recruited from a healthy community population based on a health investigation (N=119). Fasting blood samples for glucose, cholesterol, triglycerides, leptin, adiponectin, and total ghrelin were analyzed. There were significant differences in the levels of cholesterol, triglycerides, and glucose between these three groups. Post hoc comparisons showed that the olanzapine group had the highest levels of cholesterol and triglycerides. The levels of leptin, adiponectin, and total ghrelin were also significantly different between the three groups after controlling age and body mass index (BMI). Post hoc comparisons showed that the olanzapine group had the lowest levels of adiponectin and total ghrelin. The present study found that the uses of olanzapine and clozapine were associated with changes in adipocytokines and total ghrelin, even after adjusting potential confounding factors. Olanzapine had greater influences on adiponectin and total ghrelin than clozapine. The changes in adipocytokines and total ghrelin were a direct effect of antipsychotics on hormonal pathways of energy homeostasis, rather than the result of weight gain.

Olanzapine-valproate combination versus olanzapine or valproate monotherapy in the treatment of bipolar I mania: a randomized controlled study in a Chinese population group

BACKGROUND

Bipolar disorder (BP) is a mental illness that has a high social burden estimated by disability-adjusted life years. In the present study, we investigated the efficacy of olanzapine-valproate combination therapy versus olanzapine or valproate monotherapy in the treatment of bipolar I mania in a Chinese population group.

SUBJECTS AND METHODS

Patients aged 19-58 years who had had an acute manic episode of BP were enrolled in the present study and randomly assigned to receive 600 mg sodium valproate daily (group A), 10 mg olanzapine daily (group B), or a combination of 600 mg olanzapine and 10 mg sodium valproate daily (group C) for 4 weeks. The primary outcome was reduction in Young Mania Rating Scale (YMRS) scores. The secondary outcome was assessed with the Clinical Global Impression - Bipolar (CGI-BP) scale. Adverse reactions, such as weight gain, sleepy, and dizziness were also evaluated. Statistical analysis was carried out on a per-protocol basis.

RESULTS

Patients in groups B and C showed significant improvement in YMRS scores compared with those in group A (P<0.01) during weeks 1-4 of treatment. Patients in group C showed significant improvement in YMRS scores compared with those in group B (P<0.01) only after 4 weeks of treatment. Furthermore, after 3-4 weeks of treatment, patients in groups B and C showed significantly greater improvement in CGI-BP scale scores compared with group A (P<0.05), while Group C demonstrated significantly greater improvement in CGI-BP scale scores than group B (P<0.01). No significant difference existed in extrapyramidal reactions among these groups. Adverse reactions, including weight gain, drowsiness, dizziness, and constipation, were stronger in groups B and C than in group A (P<0.05).

CONCLUSION

The combination therapy with olanzapine and sodium valproate had higher efficacy than monotherapy in patients with bipolar mania, which provides a crucial insight of the treatment regimen during clinical practice.

Effects of olanzapine on the elevation of macrophage infiltration and pro-inflammatory cytokine expression in female rats

The metabolic side-effects of olanzapine have undermined drug compliance and increased concern for this otherwise-effective treatment for schizophrenia. As obesity and type 2 diabetes are associated with low-grade inflammation, and olanzapine-induced weight gain has three typical stages, the current study investigated the inflammatory effects of olanzapine in three treatment stages. Female Sprague-Dawley rats were treated orally with olanzapine (1 mg/kg three times daily) or vehicle for one week, two weeks, and five weeks. Olanzapine significantly increased body weight and white visceral fat deposition in all three treatment stages compared to control. Olanzapine enhanced average adipocyte size and level of macrophage infiltration in white adipose tissue (WAT) compared to control, with levels of macrophage infiltration increased over time. There was a high correlation between adipocyte size and macrophage infiltration rate. Olanzapine also caused increased macrophage infiltration in brown adipose tissue (BAT), but not liver. Additionally, pro-inflammatory cytokines tumor necrosis factor α (TNFα), interleukin (IL)-1β, and IL-6 were upregulated by olanzapine in the hypothalamus, WAT, and BAT compared to control, but not the liver. Finally, plasma triglycerides were elevated by olanzapine compared to control, but not total cholesterol, high density lipoprotein (HDL) or low density lipoprotein (LDL). These findings indicate that olanzapine-induced inflammation and adiposity are closely related, and that peripheral low-grade inflammation develops during olanzapine treatment.

Olanzapine reduced brown adipose tissue thermogenesis and locomotor activity in female rats

Excessive weight gain has been identified as a serious metabolic side-effect of second-generation antipsychotics (SGAs), including olanzapine. While hyperphagia has been suggested to be the main contributor for this side-effect in the short term, reduced energy expenditure, in particular thermogenesis and locomotor activity, has been considered to contribute to the maintenance of heavy weight under long-term SGA treatments. Recent studies have identified metabolically active brown adipose tissues (BAT) in adult humans, suggesting potential clinical significance for the involvement of BAT thermogenesis in SGA-induced weight gain. However, to date there has been little research elucidating the central neuronal pathways affecting BAT thermogenesis or the morphological changes of the BAT. The present study aimed to investigate the role of BAT thermogenesis and locomotor activity in olanzapine-induced weight gain during the prolonged time courses of olanzapine treatment in an established female rat model. Although short- to mid-term olanzapine treatment had no effect on BAT temperature, we observed that long-term olanzapine treatment (from day 18 to 34) induced a significant reduction in BAT temperature, with an acute effect being observed between 45 and 150 min post-treatment in the long-term cohort. Additionally, in the long-term olanzapine group, the reduced BAT temperature was accompanied by decreased UCP1 and PGC-1α expressions in the BAT. Moreover, TH mRNA expressions in both hypothalamus and brainstem were also downregulated after mid- to long-term olanzapine treatment. Further, olanzapine led to reduced percentage of brown adipocytes in BAT during mid- to long-term treatments. Finally, locomotor activity was reduced throughout the three treatment cohorts. In summary, our results suggest that the reduction of BAT thermogenesis plays an important role during the long-term of olanzapine-induced weight gain, which was accompanied by an earlier onset of BAT adipocyte morphological changes and biochemical changes in the hypothalamus and the brainstem, while locomotor activity contributes to the entire olanzapine treatment courses.

Hypothalamic ghrelin signalling mediates olanzapine-induced hyperphagia and weight gain in female rats

Excessive weight gain is a major metabolic side effect of second-generation antipsychotics (SGAs) in the treatment of schizophrenia. Ghrelin is an orexigenic hormone secreted mainly from the stomach, which can induce weight gain and hyperphagia through regulating neuropeptides at the hypothalamus. Accumulating evidence implicates a relationship between ghrelin signalling and SGA-induced hyperphagia and weight gain. We report that olanzapine (a SGA with high weight gain liability) potently and time-dependently up-regulate ghrelin and ghrelin signalling, leading to hyperphagia and weight gain in female Sprague-Dawley rats, an action reversed by i.c.v. injection of a ghrelin receptor (GHS-R1a) antagonist. These findings indicate a crucial role of ghrelin signalling in hyperphagia induced by olanzapine, supporting the notion that GHS-R1a antagonist may be useful for pharmacological treatment of SGA-induced weight gain resulted from hyperphagia.