Association of olanzapine-induced weight gain with an increase in body fat

The impact of common pharmaceutical excipients on the gut microbiota

INTRODUCTION

Increasing attention is being afforded to understanding the bidirectional relationships that exist between oral medications and the gut microbiota, in an attempt to optimize pharmacokinetic performance and mitigate unwanted side effects. While a wealth of research has investigated the direct impact of active pharmaceutical ingredients (APIs) on the gut microbiota, the interactions between inactive pharmaceutical ingredients (i.e. excipients) and the gut microbiota are commonly overlooked, despite excipients typically representing over 90% of the final dosage form.

AREAS COVERED

Known excipient-gut microbiota interactions for various classes of inactive pharmaceutical ingredients, including solubilizing agents, binders, fillers, sweeteners, and color additives, are reviewed in detail.

EXPERT OPINION

Clear evidence indicates that orally administered pharmaceutical excipients directly interact with gut microbes and can either positively or negatively impact gut microbiota diversity and composition. However, these relationships and mechanisms are commonly overlooked during drug formulation, despite the potential for excipient-microbiota interactions to alter drug pharmacokinetics and interfere with host metabolic health. The insights derived from this review will inform pharmaceutical scientists with the necessary design considerations for mitigating potential adverse pharmacomicrobiomic interactions when formulating oral dosage forms, ultimately providing clear avenues for improving therapeutic safety and efficacy.

The role of hypothalamic endoplasmic reticulum stress in schizophrenia and antipsychotic-induced weight gain: A narrative review

Schizophrenia (SCZ) is a serious mental illness that affects 1% of people worldwide. SCZ is associated with a higher risk of developing metabolic disorders such as obesity. Antipsychotics are the main treatment for SCZ, but their side effects include significant weight gain/obesity. Despite extensive research, the underlying mechanisms by which SCZ and antipsychotic treatment induce weight gain/obesity remain unclear. Hypothalamic endoplasmic reticulum (ER) stress is one of the most important pathways that modulates inflammation, neuronal function, and energy balance. This review aimed to investigate the role of hypothalamic ER stress in SCZ and antipsychotic-induced weight gain/obesity. Preliminary evidence indicates that SCZ is associated with reduced dopamine D2 receptor (DRD2) signaling, which significantly regulates the ER stress pathway, suggesting the importance of ER stress in SCZ and its related metabolic disorders. Antipsychotics such as olanzapine activate ER stress in hypothalamic neurons. These effects may induce decreased proopiomelanocortin (POMC) processing, increased neuropeptide Y (NPY) and agouti-related protein (AgRP) expression, autophagy, and leptin and insulin resistance, resulting in hyperphagia, decreased energy expenditure, and central inflammation, thereby causing weight gain. By activating ER stress, antipsychotics such as olanzapine activate hypothalamic astrocytes and Toll-like receptor 4 signaling, thereby causing inflammation and weight gain/obesity. Moreover, evidence suggests that antipsychotic-induced ER stress may be related to their antagonistic effects on neurotransmitter receptors such as DRD2 and the histamine H1 receptor. Taken together, ER stress inhibitors could be a potential effective intervention against SCZ and antipsychotic-induced weight gain and inflammation.

Current and Possible Future Therapeutic Options for Huntington’s Disease

Huntington’s disease (HD) is an autosomal neurodegenerative disease that is characterized by an excessive number of CAG trinucleotide repeats within the huntingtin gene ( HTT). HD patients can present with a variety of symptoms including chorea, behavioural and psychiatric abnormalities and cognitive decline. Each patient has a unique combination of symptoms, and although these can be managed using a range of medications and non-drug treatments there is currently no cure for the disease. Current therapies prescribed for HD can be categorized by the symptom they treat. These categories include chorea medication, antipsychotic medication, antidepressants, mood stabilizing medication as well as non-drug therapies. Fortunately, there are also many new HD therapeutics currently undergoing clinical trials that target the disease at its origin; lowering the levels of mutant huntingtin protein (mHTT). Currently, much attention is being directed to antisense oligonucleotide (ASO) therapies, which bind to pre-RNA or mRNA and can alter protein expression via RNA degradation, blocking translation or splice modulation. Other potential therapies in clinical development include RNA interference (RNAi) therapies, RNA targeting small molecule therapies, stem cell therapies, antibody therapies, non-RNA targeting small molecule therapies and neuroinflammation targeted therapies. Potential therapies in pre-clinical development include Zinc-Finger Protein (ZFP) therapies, transcription activator-like effector nuclease (TALEN) therapies and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated system (Cas) therapies. This comprehensive review aims to discuss the efficacy of current HD treatments and explore the clinical trial progress of emerging potential HD therapeutics.

Adiposity in schizophrenia: A systematic review and meta-analysis

OBJECTIVE

Although a relationship between schizophrenia (SCZ), antipsychotic (AP) medication, and metabolic dysregulation is now well established, the effect of adiposity is less well understood. By synthesizing findings from imaging techniques that measure adiposity, our systematic review and meta-analysis (PROSPERO CRD42020192977) aims to determine the adiposity-related effects of illness and treatment in this patient population.

METHODS

We searched MEDLINE, EMBASE, PsychINFO and Scopus for all relevant case-control and prospective longitudinal studies from inception until February 2021. Measures of adiposity including percent body fat (%BF), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) were analyzed as primary outcomes.

RESULTS

Our search identified 29 articles that used imaging methods to quantify adiposity among patients with SCZ spectrum disorders. Analyses revealed that patients have greater %BF (mean difference (MD) = 3.09%; 95% CI: 0.75-5.44), SAT (MD = 24.29 cm² ; 95% CI: 2.97-45.61) and VAT (MD = 33.73 cm² , 95% CI: 4.19-63.27) compared to healthy controls. AP treatment was found to increase SAT (MD = 31.98 cm² ; 95% CI: 11.33-52.64) and VAT (MD = 16.30 cm² ; 95% CI: 8.17-24.44) with no effect on %BF. However, change in %BF was higher for AP-free/AP-naïve patients compared to treated patients.

CONCLUSION

Our findings indicate that patients with SCZ spectrum disorders have greater adiposity than healthy controls, which is increased by AP treatment. Young, AP-naïve patients may be particularly susceptible to this effect. Future studies should explore the effect of specific APs on adiposity and its relation to overall metabolic health.

A meta-analysis comparing short-term weight and cardiometabolic changes between olanzapine/samidorphan and olanzapine

This study compared weight and cardiometabolic changes after short-term treatment of olanzapine/samidorphan and olanzapine. Eligible criteria for an included trial were ≤ 24 weeks, randomized controlled trials (RCTs) that compared olanzapine/samidorphan and olanzapine treatments in patients/healthy volunteers and reported weight or cardiometabolic outcomes. Three databases were searched on October 31, 2020. Primary outcomes included weight changes and all-cause dropout rates. Standardized mean differences (SMDs) and risk ratios (RRs) were computed and pooled using a random-effect model. This meta-analysis included four RCTs (n = 1195). The heterogeneous data revealed that weight changes were not significantly different between olanzapine/samidorphan and olanzapine groups (4 RCTs, SDM = − 0.19, 95% CI − 0.45 to 0.07, I² = 75%). The whole-sample, pooled RR of all-cause dropout rates (4 RCTs, RR = 1.02, 95% CI 0.84 to 1.23, I² = 0%) was not significant different between olanzapine/samidorphan and olanzapine groups. A lower percentage of males and a lower initial body mass index were associated with the greater effect of samidorphan in preventing olanzapine-induced weight gain. Current evidence is insufficient to support the use of samidorphan to prevent olanzapine-induced weight gain and olanzapine-induced cardiometabolic abnormalities. Samidorphan is well accepted by olanzapine-treated patients.

Exploring Patterns of Disturbed Eating in Psychosis: A Scoping Review

Disturbed eating behaviours have been widely reported in psychotic disorders since the early 19th century. There is also evidence that antipsychotic (AP) treatment may induce binge eating or other related compulsive eating behaviours. It is therefore possible that abnormal eating patterns may contribute to the significant weight gain and other metabolic disturbances observed in patients with psychosis. In this scoping review, we aimed to explore the underlying psychopathological and neurobiological mechanisms of disrupted eating behaviours in psychosis spectrum disorders and the role of APs in this relationship. A systematic search identified 35 studies that met our eligibility criteria and were included in our qualitative synthesis. Synthesizing evidence from self-report questionnaires and food surveys, we found that patients with psychosis exhibit increased appetite and craving for fatty food, as well as increased caloric intake and snacking, which may be associated with increased disinhibition. Limited evidence from neuroimaging studies suggested that AP-naïve first episode patients exhibit similar neural processing of food to healthy controls, while chronic AP exposure may lead to decreased activity in satiety areas and increased activity in areas associated with reward anticipation. Overall, this review supports the notion that AP use can lead to disturbed eating patterns in patients, which may contribute to AP-induced weight gain. However, intrinsic illness-related effects on eating behaviors remain less well elucidated, and many confounding factors as well as variability in study designs limits interpretation of existing literature in this field and precludes firm conclusions from being made.

High prevalence of metabolic alterations in Latin American patients at initial stages of psychosis

AIM

Studies conducted in the United States have highlighted a higher prevalence of metabolic alterations (MA) in Latino population and Latino psychotic patients. Metabolic risk in psychosis is known to be present from initial stages of the disease. To better characterize this population, we explored the prevalence of MA and metabolic syndrome (MS) in early psychosis patients in a Latin American country.

METHODS

Transversal, observational study comparing the prevalence of MA and MS in patients with early psychosis from an outpatient program in Chile (n = 148) with a community representative sample from the 2009-2010 National Health Survey (n = 568). ANOVA and regression analysis were performed obtaining odds ratio for MA and MS.

RESULTS

The prevalence of MS was 44.7% in patients compared to 11.4% in the community sample (odds ratio [OR] 5.28, confidence interval [CI] 95% 3.07-9.08; P-value <0.001). There was no effect of gender. Subgroup analyses showed no significant association of MS with clozapine/olanzapine use, treatment duration or tobacco use. There was an association between treatment duration and hypertriglyceridemia (P = 0.024; OR 1.02, CI 95% 1.00-1.04) and obesity (P = 0.007; OR 5.93, CI 95% 1.82-20.22). Clozapine/olanzapine use was associated with hyperglycaemia (P = 0.007; OR 6.04, CI 95% 1.63-22.38) and high low density lipoprotein (P = 0.033 ANOVA; OR 5.28, CI 95% 1.14-24.37).

CONCLUSION

Latino psychotic patients have a high risk of MA and MS at initial stages of the disease which is not entirely explained by the higher risk in the whole Latino population, is irrespective of gender, and does not seem to be entirely a response to atypical antipsychotic use.

A role of neuropeptide CART in hyperphagia and weight gain induced by olanzapine treatment in rats

Although olanzapine is highly efficacious and most widely used second generation antipsychotic drug, the success of treatment has been hampered by its propensity to induce weight gain. While the underlying neuronal mechanisms are unclear, their elucidation may help to target alternative pathways regulating energy balance. The present study was undertaken to define the role of cocaine- and amphetamine-regulated transcript (CART), a well-known anorexic peptide, in olanzapine-induced hyperphagia and body weight gain in female rats. Olanzapine was administered daily by intraperitoneal route, alone or in combination with CART (intracerebroventricular) for a period of two weeks. Immediately after drug administrations, preweighed food was offered to the animals at the commencement of the dark phase. The food intake and body weight were measured daily just prior to next injection. Furthermore, the brains of olanzapine-treated rats were processed for the immunohistochemical analysis of CART-containing elements in the hypothalamus. Treatment with olanzapine (0.5 mg/kg) for the duration of 14 days produced a significant increase in food intake and body weight as compared to control. However, concomitant administration of CART (0.5 µg) attenuated the olanzapine-induced hyperphagia and weight gain. Olanzapine administration resulted in a significant reduction in CART immunoreactivity in the hypothalamic arcuate, paraventricular, dorsomedial and ventromedial nuclei. We suggest that decreased CART contents in the hypothalamus may be causally linked with the hyperphagia and weight gain induced by olanzapine.

Functional Changes of Orexinergic Reaction to Psychoactive Substances

It is becoming increasingly apparent the importance of the central nervous system (CNS) as the major contributor to the regulation of systemic metabolism. Antipsychotic drugs are used often to treat several psychiatric disorders, including schizophrenia and bipolar disorder However, antipsychotic drugs prescription, particularly the second-generation ones (SGAs), such as clozapine and olanzapine, is related to a considerable weight gain which usually leads to obesity. The aim of this paper is to assess the influence of orexin A on sympathetic and hyperthermic reactions to several neuroleptic drugs. Orexin A is a neuropeptide which effects both body temperature and food intake by increasing sympathetic activity. Orexin A-mediated hyperthermia is reduced by haloperidol and is blocked by clozapine and olanzapine. Orexin A-mediated body temperature elevation is increased by risperidone. These hyperthermic effects are delayed by quietapine. In this paper, it is discussed the orexinergic pathway activation by neuroleptic drugs and its influence on human therapeutic strategies. With the aim to determine that neuroleptic drugs mediate body temperature control through to the orexinergic system, we summarized our previously published data. Psychiatric disorders increase the risk of developing metabolic disorders (e.g., weight gain, increased blood pressure, and glucose or lipid levels). Therefore, the choice of antipsychotic drug to be prescribed, based on the relevant risks and benefits of each individual drug, has an essential role in human health prevention.

Oral haloperidol or olanzapine intake produces distinct and region-specific increase in cannabinoid receptor levels that is prevented by high fat diet

Clinical studies show higher levels of cannabinoid CB1 receptors (CB1R) in the brain of schizophrenic patients while preclinical studies report a significant functional interaction between dopamine D2 receptors and CB1Rs as well as an upregulation of CB1Rs after antipsychotic treatment. These findings prompted us to study the effects of chronic oral intake of a first and a second generation antipsychotic, haloperidol and olanzapine, on the levels and distribution of CB1Rs in the rat brain. Rats consumed either regular chow or high-fat food and drank water, haloperidol drinking solution (1.5mg/kg), or olanzapine drinking solution (10mg/kg) for four weeks. Motor and cognitive functions were tested at the end of treatment week 3 and upon drug discontinuation. Two days after drug discontinuation, rats were euthanized and brains were processed for in vitro receptor autoradiography. In chow-fed animals, haloperidol and olanzapine increased CB1R levels in the basal ganglia and the hippocampus, in a similar, but not identical pattern. In addition, olanzapine had unique effects in CB1R upregulation in higher order cognitive areas, in the secondary somatosensory cortex, in the visual and auditory cortices and the geniculate nuclei, as well as in the hypothalamus. High fat food consumption prevented antipsychotic-induced increase in CB1R levels in all regions examined, with one exception, the globus pallidus, in which they were higher in haloperidol-treated rats. The results point towards the hypothesis that increased CB1R levels could be a confounding effect of antipsychotic medication in schizophrenia that is circumveneted by high fat feeding.

Prevalence of Metabolic Syndrome in Patients with Schizophrenia in Korea: A Multicenter Nationwide Cross-Sectional Study

OBJECTIVE

We designed a nationwide study with limited exclusion criteria to investigate the prevalence of metabolic syndrome (MetS) in Korea and its relationship with antipsychotic medications.

METHODS

This multicenter, cross-sectional, and observational study included patients diagnosed with schizophrenia or schizoaffective disorder. Sixteen hospitals enrolled 845 patients aged 18 to 65 years prescribed any antipsychotic medication between August 2011 and August 2013. MetS was diagnosed using the criteria of the modified Adult Treatment Panel III of the National Cholesterol Education Program with the Korean abdominal obesity definition (waist circumference ≥85 cm in women, ≥90 cm in men).

RESULTS

The prevalence of MetS in all patients was 36.5% and was significantly higher in men than women (men, 40.8%; women, 32.2%) and was significantly correlated with age [odds ratio (OR) 1.02] and duration of illness (OR 1.03). The prevalence of MetS across antipsychotic drugs in the major monotherapy group was as follows: 18.8% for quetiapine, 22.0% for aripiprazole, 33.3% for both amisulpride and paliperidone, 34.0% for olanzapine, 35% for risperidone, 39.4% for haloperidol, and 44.7% for clozapine.

CONCLUSION

The prevalence of MetS is very high in patients with schizophrenia or schizoaffective disorder. Screening and monitoring of MetS is also strongly recommended.

Ameliorative Effect of Curcumin on Olanzapine-induced Obesity in Sprague-Dawley Rats

OBJECTIVE

To evaluate the effect of curcumin on olanzapine-induced obesity in rats.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were used for experiments. The animals were divided into six groups, namely, normal control, olanzapine control, betahistine (10 mg/kg), and curcumin 50, 100, and 200 mg/kg treated groups. Except the normal control group, all other animals were administered with olanzapine 4 mg/kg intraperitoneally to induce obesity. The drugs were administered once daily, per oral for 28 days. During the experiment, body weight changes and behavior alterations were monitored at regular intervals. At the end of the experiment, blood sample was collected from all the experimental animals for biochemical analysis. Part of the liver and kidney tissues was harvested from the sacrificed animals and preserved in neutral formalin for histopathological studies.

RESULTS

Curcumin showed a significant reduction in olanzapine-induced body weight gain on the rats and improved the locomotor effects. The effect of curcumin on olanzapine-induced body weight gain is not comparable with that of betahistine.

CONCLUSION

This study has shown metabolic alteration effect of curcumin on olanzapine, an antipsychotic drug, treated SD rats.

SUMMARY

Olanzapine is an atypical antipsychotic drug used for the treatment of schizophrenia and bipolar disorder. Obesity is an adverse effect of olanzapine, and the present study was made an attempt to study the effect of curcumin on olanzapine-induced obesity in rats. In this present study, curcumin significantly reduced olanzapine-induced body weight gain in rats. Abbreviations Used: 5HT: 5-hydroxytryptamine, ALP: Alkaline phosphatase, ALT: Alanine transaminase, ANOVA: Analysis of variance, AST: Aspartate transaminase, CMC: Carboxymethyl cellulose, D: Dopamine, H and E: Hematoxylin and Eosin stain, H: Histamine, HDL-C: Highdensity lipoprotein cholesterol, IP: Intraperitoneal, MAO: Monoamine oxidase, NaOH: Sodium hydroxide, SD rats: Sprague Dawley rats, TCs: Total cholesterols, TG: Triglyceride.

Atypical antipsychotics and effects on feeding: from mice to men

RATIONALE

So-called atypical antipsychotics (AAPs) are associated with varying levels of weight gain and associated metabolic disturbances, which in patients with serious mental illness (SMI) have been linked to non-compliance and poor functional outcomes. Mechanisms underlying AAP-induced metabolic abnormalities are only partially understood. Antipsychotic-induced weight gain may occur as a result of increases in food intake and/or changes in feeding.

OBJECTIVE

In this review, we examine the available human and preclinical literature addressing AAP-related changes in feeding behavior, to determine whether changes in appetite and perturbations in regulation of food intake could be contributing factors to antipsychotic-induced weight gain.

RESULTS

In general, human studies point to disruption by AAPs of feeding behaviors and food consumption. In rodents, increases in cumulative food intake are mainly observed in females; however, changes in feeding microstructure or motivational aspects of food intake appear to occur independent of sex.

CONCLUSIONS

The findings from this review indicate that the varying levels of AAP-related weight gain reflect changes in both appetite and feeding behaviors, which differ by type of AAP. However, inconsistencies exist among the studies (both human and rodent) that may reflect considerable differences in study design and methodology. Future studies examining underlying mechanisms of antipsychotic-induced weight gain are recommended in order to develop strategies addressing the serious metabolic side effect of AAPs.

Lithium vs. valproate vs. olanzapine vs. quetiapine as maintenance monotherapy for bipolar disorder: a population-based UK cohort study using electronic health records

It is unclear which maintenance treatment for bipolar disorder is superior in clinical practice. Randomized controlled head-to-head trials of available drugs either do not exist or are inconclusive. We aimed to compare rates of monotherapy treatment failure in individuals prescribed lithium, valproate, olanzapine or quetiapine by a population-based cohort study using electronic health records. 5,089 patients with bipolar disorder were prescribed lithium (N=1,505), valproate (N=1,173) olanzapine (N=1,366) or quetiapine (N=1,075) as monotherapy. Treatment failure was defined as time to stopping medication or add-on of another mood stabilizer, antipsychotic, antidepressant or benzodiazepine. In unadjusted analyses, the duration of successful monotherapy was longest in individuals treated with lithium. Treatment failure had occurred in 75% of those prescribed lithium by 2.05 years (95% CI: 1.63-2.51), compared to 0.76 years (95% CI: 0.64-0.84) for those prescribed quetiapine, 0.98 years (95% CI: 0.84-1.18) for those prescribed valproate, and 1.13 years for those prescribed olanzapine (95% CI: 1.00-1.31). Lithium's superiority remained in a propensity score matched analysis; when treatment failure was defined as stopping medication or add-on of a mood stabilizer or antipsychotic; and when treatment failure was restricted to more than three months after commencing the study drug. Lithium appears to be more successful as monotherapy maintenance treatment than valproate, olanzapine or quetiapine. Lithium is often avoided because of its side effect profile, but alternative treatments may reduce the time to being prescribed more than one drug, with potential additive side effects of these treatments.

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.

Olanzapine inhibits proliferation, migration and anchorage-independent growth in human glioblastoma cell lines and enhances temozolomide's antiproliferative effect

The poor prognosis of patients with glioblastoma fuels the search for more effective therapeutic compounds. We previously hypothesised that the neuroleptic olanzapine may enhance antineoplastic effects of temozolomide the standard chemotherapeutic agent used in this disease. This study tested this hypothesis. The anti-proliferative effect of olanzapine was examined by MTT assays and cell count analysis. Soft-agar assays were performed to examine colony-forming ability. In addition, the inhibitory effect of olanzapine on the migratory capacity of U87MG and A172 cells was analyzed by Transwell(®) assays. Moreover, staining for annexin V/propidium iodide or carboxyfluorescein succinimidyl ester was performed prior to flow cytometric analysis in order to better understand the subjacent cellular mechanism. Our initial hypothesis that olanzapine may enhance temozolomide's anti-tumor activity could be confirmed in U87MG and A172 glioblastoma cell lines. Moreover, treatment with olanzapine alone resulted in a marked anti-proliferative effect on U87MG, A172 and two glioma stem-like cells with IC50 values ranging from 25 to 79.9 µM. In U87MG cells, anchorage-independent growth was dose-dependently inhibited. In A172 cells, migration was also shown to be inhibited in a dose-dependent manner. In addition, olanzapine was shown to exert a cell line-dependent pleomorphism with respect to the induction of apoptosis, necrosis and/or cytostasis. Our data show that the neuroleptic olanzapine enhances the anti-tumor activity of temozolomide against glioblastoma cell lines. Moreover, this is the first study to show that olanzapine provides on its own anti-cancer activity in glioblastoma and thus may have potential for repurposing.

Molecular and cellular regulation of hypothalamic melanocortin neurons controlling food intake and energy metabolism

The brain receives and integrates environmental and metabolic information, transforms these signals into adequate neuronal circuit activities, and generates physiological behaviors to promote energy homeostasis. The responsible neuronal circuitries show lifetime plasticity and guaranty metabolic health and survival. However, this highly evolved organization has become challenged nowadays by chronic overload with nutrients and reduced physical activity, which results in an ever-increasing number of obese individuals worldwide. Research within the last two decades has aimed to decipher the responsible molecular and cellular mechanisms for regulation of the hypothalamic melanocortin neurons, which have a key role in the control of food intake and energy metabolism. This review maps the central connections of the melanocortin system and highlights its global position and divergent character in physiological and pathological metabolic events. Moreover, recently uncovered molecular and cellular processes in hypothalamic neurons and glial cells that drive plastic morphological and physiological changes in these cells, and account for regulation of food intake and energy metabolism, are brought into focus. Finally, potential functional interactions between metabolic disorders and psychiatric diseases are discussed.

Recent evidence and potential mechanisms underlying weight gain and insulin resistance due to atypical antipsychotics

OBJECTIVE

Atypical antipsychotics (AAPs) promote obesity and insulin resistance. In this regard, the main objective of this study was to present potential mechanisms and evidence concerning side effects of atypical antipsychotics in humans and rodents.

METHOD

A systematic review of the literature was performed using the MEDLINE database. We checked the references of selected articles, review articles, and books on the subject.

RESULTS

This review provides consistent results concerning the side effects of olanzapine (OL) and clozapine (CLZ), whereas we found conflicting results related to other AAPs. Most studies involving humans describe the effects on body weight, adiposity, lipid profile, and blood glucose levels. However, it seems difficult to identify an animal model replicating the wide range of changes observed in humans. Animal lineage, route of administration, dose, and duration of treatment should be carefully chosen for the replication of the findings in humans.

CONCLUSIONS

Patients undergoing treatment with AAPs are at higher risk of developing adverse metabolic changes. This increased risk must be taken into account when making decisions about treatment. The influence of AAPs on multiple systems is certainly the cause of such effects. Specifically, muscarinic and histaminergic pathways seem to play important roles.

Modelling olanzapine-induced weight gain in rats

The second-generation antipsychotic drug olanzapine has become a widely prescribed drug in the treatment of schizophrenia and bipolar disorder. Unfortunately, its therapeutic benefits are partly outweighed by significant weight gain and other metabolic side effects, which increase the risk for diabetes and cardiovascular disease. Because olanzapine remains superior to other antipsychotic drugs that show less weight gain liability, insight into the mechanisms responsible for olanzapine-induced weight gain is crucial if it is to be effectively addressed. Over the past few decades, several groups have investigated the effects of olanzapine on energy balance using rat models. Unfortunately, results from different studies have not always been consistent and it remains to be determined which paradigms should be used in order to model olanzapine-induced weight gain most accurately. This review summarizes the effects of olanzapine on energy balance observed in different rat models and discusses some of the factors that appear to contribute to the inconsistencies in observed effects. In addition it compares the effects reported in rats with clinical findings to determine the predictive validity of different paradigms.

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.

Potential mechanisms of atypical antipsychotic-induced hypertriglyceridemia

RATIONALE AND BACKGROUND

The development of atypical antipsychotic (AAP) drugs has brought about dramatic improvement in the function of many patients with schizophrenia and related mental disorders. However, prescription of AAPs is frequently associated with the emergence of weight gain, hypertriglyceridemia, and other metabolic disturbances. Although the mechanisms involved in AAP-induced hypertriglyceridemia remain to be fully elucidated, several studies have proposed that this side effect may be associated with weight gain and obesity. Recently, special emphasis has been placed on the evidence indicating a direct effect of AAPs on triglyceride metabolism.

OBJECTIVES

In this review, we highlight recent findings discussing the potential mechanisms by which AAPs may contribute to hypertriglyceridemia. In addition, we summarize the adjunctive pharmacologic treatments for AAP-associated dyslipidemia.

CONCLUSIONS

There is evidence that AAPs may cause hypertriglyceridemia through several possible mechanisms: (1) a direct effect on triglyceride metabolism either by stimulation of hepatic triglyceride production and secretion or by inhibition of lipoprotein lipase-mediated triglyceride hydrolysis and (2) an indirect mechanism associated with obesity and insulin resistance. The practical applications of this manuscript provide new insights for the future investigation of AAPs.

Metabolic syndrome in schizophrenia: Differences between antipsychotic-naïve and treated patients

Metabolic syndrome (MetS) has been recognized as a risk factor for cardiovascular morbidity and mortality in general population and in patients with severe mental illnesses like schizophrenia. This paper reviews studies on MetS in schizophrenia and related psychotic disorders, and assesses the contribution of antipsychotics toward the development of MetS. Databases of Medline (PubMed), PsycINFO, and Scopus were searched for MetS, psychotic disorders, and antipsychotic drugs from inception till present. Prevalence of MetS in patients with schizophrenia was found to be ranging from 3.3% to 68.0%. Prevalence in antipsychotic-naïve and antipsychotic-treated patients ranged between 3.3-26.0% and 32.0-68.0% respectively, and was higher in younger patients, female gender and Hispanics, and lower in African-Americans and Orientals. Prevalence of metabolic abnormalities was higher in patients receiving second generation antipsychotics (SGAs), especially with clozapine, olanzapine, and risperidone, as compared to first generation antipsychotics (FGAs). Antipsychotic-induced changes on metabolic indices became evident after 2 weeks and reached maximum at 3 months of treatment. There is a need to sensitize the mental health professionals at all levels about the need of screening and monitoring for MetS in patients receiving antipsychotics.

The investigation of leptin and hypothalamic neuropeptides role in first attack psychotic male patients: olanzapine monotherapy

The mechanism underlying the weight gain due to treatment with olanzapine and other second generation antipsychotics has not been fully understood. To examine olanzapine's weight gain effects, we accepted first attack psychotic patients with no medication (pre-treatment) (n=22) and the healthy control group (n=26) in this study. After patientś diagnosis, they were hospitalized and then treated for four weeks with olanzapine (post-treatment). We used case-control association design to test body mass index (BMI) and biochemical changes in each group. We also investigated peripheral leptin and neuropeptides/hormones namely, pro-opiomelanocortin (POMC), cocaine and amphetaime regulated transcript (CART), and neuropeptide Y (NPY) levels. These neuropeptides which are synthesized/secreted from arcuate nucleus of hypothalamus affect food intake and therefore, body weight. After 4 weeks of olanzapine treatment; BMI (body mass index), waist circumference, blood triglyceride, total cholesterol, and very low density lipoprotein (VLDL) levels were increased significantly in patients compared to their pre-treatment baseline. In pre-treatment, patients' NPY levels were significantly lower while α-MSH, the anorexigenic product of POMC levels were significantly higher vs. control. Both leptin and NPY levels were significantly increased in patients after the treatment but the NPY levels were also significantly lower in post-treatment vs. the control group. The CART levels did not change after the treatment. We may presume that the antagonist effect of olanzapine on the serotonin (5HT2CR and 5HT1BR) receptors of the arcuate hypothalamic neurons may be a basis for a deregulation of the neurohormones secretion.

Atypical antipsychotics and diabetic ketoacidosis: a review

RATIONALE

Atypical antipsychotics have been linked to weight gain and type 2 diabetes, but are also associated with diabetic ketoacidosis (DKA), which can occur more acutely and in the absence of weight gain.

OBJECTIVES

Our aim was to review current case reports of DKA in the context of atypical antipsychotic treatment to better understand (a) the scope of the problem, (b) its relationship to different atypical agents, (c) risk factors, (d) long-term outcome, and (e) putative mechanisms of action.

METHOD

Searches in PubMed/Medline, as well as the University of Toronto's Scholar Portal, were performed for all relevant articles/abstracts in English.

RESULTS

Sixty reports, yielding 69 cases, affirm that DKA is a rare but serious risk with almost all atypical antipsychotics; however, liability seems to vary between agents, at least partially mirroring risk of weight gain. Mean age of onset was 36.9 years (range 12-80), with 68 % of cases occurring in males, and 41 % in individuals of African American or African Caribbean descent. Over one third of cases present with either no weight gain or weight loss, and 61 % of these require ongoing treatment for glycemic control. Death occurred in 7.25 % of cases.

CONCLUSION

While the underlying mechanisms are not well understood, antipsychotic-related DKA can occur soon after treatment onset and in the absence of weight gain. Although rare, clinicians must remain vigilant given its acute onset and potential lethality.

Soccer practice as an add-on treatment in the management of individuals with a diagnosis of schizophrenia

Physical activity is an important aspect of good health for everyone; it is even more important for psychiatric patients who usually live an unhealthy lifestyle. In recent years, there has been growing focus on the use of soccer as a vehicle to improve the health of subjects with severe mental illness. The aim of this study was to investigate the effects of soccer practice on the self-reported health quality of life (SRHQL) and sports performance (SP) in psychotic subjects. Eighteen male patients with diagnosis of schizophrenia were randomized into either a trained (TG) or a control group (CG). The TG was trained for 12 weeks using two soccer training sessions per week. The CG did not perform any regular sports activity during the experimental period. Anthropometric measurements, SRHQL, personal time records in a 30 meter sprint test and slalom test running with a ball were evaluated before and after the experimental period. SRHQL was assessed using Short Form-12 questionnaire measuring physical and mental component summary scores. After the training period, the TG showed a relevant decrease by 4.6% in bodyweight (BW) and body mass index compared to baseline. Conversely, the CG showed an increased BW and body mass index by 1.8% from baseline to posttest. Moreover, after 12 weeks we found that control patients increased their BW significantly when compared to trained patients (Δ = 5.4%; P < 0.05). After the training period, comparing the baseline TG's Short Form-12-scores to posttest results, we found an improvement of 10.5% and 10.8% in physical component summary and mental component summary, respectively. In addition, performances on the 30 meter sprint test and slalom test running with a ball in the TG improved significantly (P < 0.01) from baseline to posttest when compared to CG. Soccer practice appears able to improve psychophysical health in individuals with diagnosis of schizophrenia. Indeed, our study demonstrated that programmed soccer physical activity could reduce antipsychotic medication-related weight gain and improve SRHQL and sports performance in psychotic subjects.

Dysregulation of adipocytokines related to second-generation antipsychotics in normal fasting glucose patients with schizophrenia

OBJECTIVE

The underlying mechanism for second-generation antipsychotic (SGA)-related glucose-lipid metabolic dysfunction is not fully understood. Recent studies have suggested a possible impact of SGAs on endocrine regulation, especially on adipocytokines. We examined the effect of each SGA on various adipocytokines in normal fasting glucose (NFG) subjects.

METHOD

The study population comprised 113 Japanese inpatients with schizophrenia who were treated with olanzapine, risperidone, or quetiapine, and 123 healthy control (CONT) volunteers. All of the subjects were diagnosed with NFG. Plasma concentration of adiponectin, leptin, tumor necrosis factor α, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were compared between the SGA and CONT groups.

RESULTS

Second-generation antipsychotic subjects had significantly higher leptin levels in comparison to the CONT subjects. The plasma concentration of adiponectin, total cholesterol, and high-density lipoprotein cholesterol in the SGA subjects were significantly lower than those in the CONT subjects. There were no significant differences in tumor necrosis factor α, triglyceride, and low-density lipoprotein cholesterol levels between the 2 groups. In a stepwise multiple regression analysis, olanzapine was found to be a factor that contributed to decreased adiponectin levels, and the CONT subjects were detected to be a factor associated with lower leptin levels.

CONCLUSIONS

The present study indicates the possibility that the administration of SGAs may affect adipocytokines in the NFG stage, excluding the impaired fasting glucose group, which is in the transition stage into diabetes mellitus.

Neural changes associated with appetite information processing in schizophrenic patients after 16 weeks of olanzapine treatment

There is evidence that some atypical antipsychotics, including olanzapine, can produce unwanted metabolic side effects, weight gain and diabetes. However, neuronal correlates of change related to food information processing have not been investigated with these medications. We studied the effect of a pharmacological manipulation with an antipsychotic known to cause weight gain on metabolites, cognitive tasks and neural correlates related to food regulation. We used functional magnetic resonance imaging in conjunction with a task requiring visual processing of appetitive stimuli in schizophrenic patients and healthy controls before and after 16 weeks of antipsychotic medication with olanzapine. In patients, the psychological and neuronal changes associated following the treatment correlated with appetite control measures and metabolite levels in fasting blood samples. After 16 weeks of olanzapine treatment, the patients gained weight, increased their waist circumference, had fewer positive schizophrenia symptoms, a reduced ghrelin plasma concentration and an increased concentration of triglycerides, insulin and leptin. In premotor area, somatosensory cortices as well as bilaterally in the fusiform gyri, the olanzapine treatment increased the neural activity related to appetitive information in schizophrenic patients to similar levels relative to healthy individuals. However, a higher increase in sensitivity to appetitive stimuli after the treatment was observed in insular cortices, amygdala and cerebellum in schizophrenic patients as compared with healthy controls. Furthermore, these changes in neuronal activity correlated with changes in some metabolites and cognitive measurements related to appetite regulation.

Are cardiometabolic and endocrine abnormalities linked to sleep difficulties in schizophrenia? A hypothesis driven review

Schizophrenia is a psychiatric disorder that includes symptoms such as hallucinations, disordered thoughts, disorganized or catatonic behaviour, cognitive dysfunction and sleep-wake disturbance. In addition to these symptoms, cardiometabolic dysfunction is common in patients with schizophrenia. While previously it has been thought that cardiometabolic symptoms in patients with schizophrenia were associated with medications used to manage this disorder, more recently it has been demonstrated that these symptoms are present in drug naive and unmedicated patients. Sleep-wake disturbance, resulting in chronic sleep loss has also been demonstrated to induce changes in cardiometabolic function. Chronic sleep loss has been associated with an increased risk for weight gain, obesity and cardiac and metabolic disorders, independent of other potentially contributing factors, such as smoking and body mass index. We hypothesise that the sleep-wake disturbance comorbid with schizophrenia may play a significant role in the high prevalence of cardiometabolic dysfunction observed in this patient population. Here we present a critical review of the evidence that supports this hypothesis.

Alterations to melanocortinergic, GABAergic and cannabinoid neurotransmission associated with olanzapine-induced weight gain

Background/Aim

Second generation antipsychotics (SGAs) are used to treat schizophrenia but can cause serious metabolic side-effects, such as obesity and diabetes. This study examined the effects of low to high doses of olanzapine on appetite/metabolic regulatory signals in the hypothalamus and brainstem to elucidate the mechanisms underlying olanzapine-induced obesity.

Methodology/Results

Levels of pro-opiomelanocortin (POMC), neuropeptide Y (NPY) and glutamic acid decarboxylase (GAD₆₅, enzyme for GABA synthesis) mRNA expression, and cannabinoid CB1 receptor (CB1R) binding density (using [³H]SR-141716A) were examined in the arcuate nucleus (Arc) and dorsal vagal complex (DVC) of female Sprague Dawley rats following 0.25, 0.5, 1.0 or 2.0 mg/kg olanzapine or vehicle (3×/day, 14-days). Consistent with its weight gain liability, olanzapine significantly decreased anorexigenic POMC and increased orexigenic NPY mRNA expression in a dose-sensitive manner in the Arc. GAD₆₅ mRNA expression increased and CB1R binding density decreased in the Arc and DVC. Alterations to neurotransmission signals in the brain significantly correlated with body weight and adiposity. The minimum dosage threshold required to induce weight gain in the rat was 0.5 mg/kg olanzapine.

Conclusions

Olanzapine-induced weight gain is associated with reduced appetite-inhibiting POMC and increased NPY. This study also supports a role for the CB1R and GABA in the mechanisms underlying weight gain side-effects, possibly by altering POMC transmission. Metabolic dysfunction can be modelled in the female rat using low, clinically-comparable olanzapine doses when administered in-line with the half-life of the drug.

The role of leptin in antipsychotic-induced weight gain: genetic and non-genetic factors

Schizophrenia is a chronic and disabling mental illness affecting millions of people worldwide. A greater proportion of people with schizophrenia tends to be overweight. Antipsychotic medications have been considered the primary risk factor for obesity in schizophrenia, although the mechanisms by which they increase weight and produce metabolic disturbances are unclear. Several lines of research indicate that leptin could be a good candidate involved in pathways linking antipsychotic treatment and weight gain. Leptin is a circulating hormone released by adipocytes in response to increased fat deposition to regulate body weight, acting through receptors in the hypothalamus. In this work, we reviewed preclinical, clinical, and genetic data in order to infer the potential role played by leptin in antipsychotic-induced weight gain considering two main hypotheses: (1) leptin is an epiphenomenon of weight gain; (2) leptin is a consequence of antipsychotic-induced "leptin-resistance status," causing weight gain.

Evaluation of efficacy, safety, and cognitive profile of amisulpride per se and its comparison with olanzapine in newly diagnosed schizophrenic patients in an 8-week, double-blind, single-centre, prospective clinical trial

Background. Impaired cognitive functions in schizophrenia are the major deciding factors in response to treatment. Conventional antipsychotics have minimal impact on cognitive dysfunctions and are associated with adverse effects. Atypical antipsychotics have shown promise in treatment of cognitive and negative symptoms of schizophrenia. Efforts are underway to find out the best drug amongst atypical antipsychotics. Objective. To compare efficacy, safety, and cognitive profile of amisulpride and olanzapine in the treatment of acute psychotic exacerbations of schizophrenia. Method. A prospective, randomized, double-blind, single-center, 8-week clinical trial we used. Subjects and Treatments. Seventy four patients were treated for two months with either amisulpride (400-800 mg/d) or olanzapine (10-20 mg/d). Statistics. Mann Whitney U test we used for independent samples with P < 0.05 taken as significant. Results. Brief psychiatric rating scale (BPRS) was used as a primary measure of efficacy. Other measures of efficacy and safety were also evaluated. Both amisulpride and olanzapine groups showed equivalent improvement in psychotic symptoms on BPRS scale. Less than five percent of patients suffered adverse effects only to withdraw from the study. Olanzapine group showed statistically significant (P < 0.05) weight gain compared with amisulpride group. Amisulpride group showed significant improvement (P < 0.05) in various cognitive parameters as compared to olanzapine group.

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

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

A double blind, placebo-controlled, randomized crossover study of the acute metabolic effects of olanzapine in healthy volunteers

Background and Rationale

Atypical antipsychotics exhibit metabolic side effects including diabetes mellitus and obesity. The adverse events are preceded by acute worsening of oral glucose tolerance (oGTT) along with reduced plasma free fatty acids (FFA) and leptin in animal models. It is unclear whether the same acute effects occur in humans.

Methodology/Principal Findings

A double blind, randomized, placebo-controlled crossover trial was conducted to examine the potential metabolic effects of olanzapine in healthy volunteers. Participants included male (8) and female (7) subjects [18–30 years old, BMI 18.5–25]. Subjects received placebo or olanzapine (10 mg/day) for three days prior to oGTT testing. Primary endpoints included measurement of plasma leptin, oral glucose tolerance, and plasma free fatty acids (FFA). Secondary metabolic endpoints included: triglycerides, total cholesterol, high- and low-density lipoprotein cholesterol, heart rate, blood pressure, body weight and BMI. Olanzapine increased glucose Area Under the Curve (AUC) by 42% (2808±474 vs. 3984±444 mg/dl·min; P = 0.0105) during an oGTT. Fasting plasma leptin and triglycerides were elevated 24% (Leptin: 6.8±1.3 vs. 8.4±1.7 ng/ml; P = 0.0203) and 22% (Triglycerides: 88.9±10.1 vs. 108.2±11.6 mg/dl; P = 0.0170), whereas FFA and HDL declined by 32% (FFA: 0.38±0.06 vs. 0.26±0.04 mM; P = 0.0166) and 11% (54.2±4.7 vs. 48.9±4.3 mg/dl; P = 0.0184), respectively after olanzapine. Other measures were unchanged.

Conclusions/Significance

Olanzapine exerts some but not all of the early endocrine/metabolic changes observed in rodent models of the metabolic side effects, and this suggest that antipsychotic effects are not limited to perturbations in glucose metabolism alone. Future prospective clinical studies should focus on identifying which reliable metabolic alterations might be useful as potential screening tools in assessing patient susceptibility to weight gain and diabetes caused by atypical antipsychotics.

Trial Registration

ClinicalTrials.gov NCT00741026

[Psychotropic drugs and diabetes]

Psychotropic drugs, such as antipsychotics and antidepressants, are widely used substances which can display marked metabolic side effects. Psychiatric patients display increased morbidity and mortality which, besides disease specific factors, may be attributed to metabolic side effects of psychotropic drugs. Commonly observed side effects of antipsychotics are weight gain as well as disturbances in glucose and lipid metabolism. Additionally, antipsychotics have been shown to increase diabetes risk. Also, the use of some of the antidepressant substances is associated with an increased diabetes risk. However, large inter-substance variations have been observed. Conversely, diabetics have an increased risk of depression. Metabolic side effects of psychotropic drugs pose a serious impairment for psychiatric patients and their management can play a pivotal role in therapeutic compliance and success. This review aims to give an overview of metabolic side effects of commonly used psychotic drugs and to give an insight into possible underlying mechanisms.

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.

Beneficial effect of the insulin sensitizer (HSP inducer) BGP-15 on olanzapine-induced metabolic disorders

Olanzapine is a widely used atypical antipsychotic, with well known metabolic side effects such as weight gain, insulin resistance and blood glucose abnormalities. It has been previously shown in a phase II clinical trial that BGP-15, an amidoxim derivative has insulin-sensitizing effects. The aim of this study was to investigate the efficacy of BGP-15 for the treatment of olanzapine-induced metabolic side effects, in healthy volunteers. Thirty-seven (37) subjects (ages 18-55 years) with normal glucose metabolism were randomly assigned to 17 days of once-daily treatment with 400mg of BGP-15 or placebo and 5mg of olanzapine for 3 days followed by 10mg for 14 days. Total body and muscle tissue glucose utilization was determined by hyperinsulinemic-euglycemic clamp technique. As expected the 17-day olanzapine treatment provoked insulin resistance and body weight gain (p<0.05) in both groups. Administration of BGP-15 significantly reduced olanzapine-induced insulin resistance. The protective effect of BGP-15 on insulin stimulated glucose utilization had the highest magnitude in the values calculated for the muscle tissue (p=0.002). In healthy individuals BGP-15 was safe and well tolerated during the whole study period. It is suggested that BGP-15 can be a successful insulin sensitizer agent to prevent side effects of olanzapine treatment.

Acute effects of olanzapine on behavioural expression including the behavioural satiety sequence in female rats

Olanzapine is a novel antipsychotic drug known to induce clinically significant weight gain. Although the cause of such weight gain is not fully known, drug-induced changes in appetite and food intake are likely to play a significant role together with other possible mechanisms enhancing weight and/or adiposity. We assessed acute drug effects on 1 hour intake and behavioural expression in female rats. Low doses of olanzapine (0.5 and 1 mg/kg) enhanced acute mash intake. Marked drug effects were seen on a number of behaviours following olanzapine over a range of doses. These effects included dose-related reductions in activity and exploratory behaviours and associated substantial dose-related increases in resting behaviour. Behavioural data were also used to plot drug effects over time, including behavioural satiety sequence (BSS) profiles, to evaluate whether olanzapine's hyperphagic effects might be a consequence of altered satiety development. BSS profiles reflected enhanced eating behaviour at low doses (0.5 and 1 mg/kg) but showed dose-related increases in resting, indicative of drug-induced sedation, which meant that it was impossible to fully discern olanzapine's effects on satiety. Acute olanzapine induces both hyperphagia and sedation, both of which may promote weight gain and adiposity, but which interact competitively.

The neurotrophic and neuroprotective effects of psychotropic agents

Accumulating evidence suggests that psychotropic agents such as mood stabilizers, antidepressants, and antipsychotics realize their neurotrophic/neuroprotective effects by activating the mitogen activated protein kinaselextracellular signal-related kinase, PI3-kinase, and winglesslglycogen synthase kinase (GSK) 3 signaling pathways. These agents also upregulate the expression of trophic/protective molecules such as brain-derived neurotrophic factor, nerve growth factor, B-cell lymphoma 2, serine-threonine kinase, and Bcl-2 associated athanogene 1, and inactivate proapoptotic molecules such as GSK-3, They also promote neurogenesis and are protective in models of neurodegenerative diseases and ischemia. Most if not all, of this evidence was collected from animal studies that used clinically relevant treatment regimens. Furthermore, human imaging studies have found that these agents increase the volume and density of brain tissue, as well as levels of N-acetyl aspartate and glutamate in selected brain regions. Taken together, these data suggest that the neurotrophic/neuroprotective effects of these agents have broad therapeutic potential in the treatment, not only of mood disorders and schizophrenia, but also neurodegenerative diseases and ischemia.

Obesity, serious mental illness and antipsychotic drugs

The prevalence of overweight and obesity is higher in people with mental illness than in the general population. Body weight is tightly regulated by a complex system involving the cortex and limbic system, the hypothalamus and the gastrointestinal tract. While there are justifiable concerns about the weight gain associated with antipsychotic medication, it is too simplistic to ascribe all obesity in people with serious mental illness (SMI) to their drug treatment. The development of obesity in SMI results from the complex interaction of the genotype and environment of the person with mental illness, the mental illness itself and antipsychotic medication. There are dysfunctional reward mechanisms in SMI that may contribute to poor food choices and overeating. While it is clear that antipsychotics have profound effects to stimulate appetite, no one receptor interaction provides an adequate explanation for this effect, and many mechanisms are likely to be involved. The complexity of the system regulating body weight allows us to start to understand why some individuals appear much more prone to weight gain and obesity than others.

The role of thermogenesis in antipsychotic drug-induced weight gain

The administration of antipsychotic drugs to human patients or experimental animals leads to significant weight gain, which is widely presumed to be driven by hyperphagia; however, the contribution from energy expenditure remains unclear. These studies aim to examine the contribution of shifts in energy expenditure, particularly those involving centrally mediated changes in thermogenesis, to the body weight gain associated with the administration of olanzapine to female Sprague Dawley rats. Olanzapine (6 mg/kg/day orally) caused a transient increase in food intake but a maintained increase in body weight. When pair-fed rats were treated with olanzapine, body weight continued to rise compared to vehicle-treated rats, consistent with a reduction in energy expenditure. Brown adipose tissue (BAT) temperature, measured using biotelemetry devices, decreased immediately after the onset of olanzapine treatment and remained depressed, as did physical activity. UCP1 expression in interscapular BAT was reduced following chronic olanzapine treatment. An acute injection of olanzapine was preceded by an injection of a retrograde tracer into the spinal cord to evaluate the nature of the olanzapine-activated neural pathway. Levels of Fos protein in a number of spinally projecting neurons within discrete hypothalamic and brainstem sites were elevated in olanzapine-treated rats. Some of these neurons in the perifornical region of the lateral hypothalamus (LHA) were also Orexin A positive. These data collectively show a significant impact of thermogenesis (and physical activity) on the weight gain associated with olanzapine treatment. The anatomical studies provide an insight into the central neuroanatomical substrate that may subserve the altered thermogenic responses brought about by olanzapine.

Leptin and ghrelin levels in patients with schizophrenia during different antipsychotics treatment: a review

Energy homeostasis is achieved by the integration of peripheral metabolic signals by the neural circuits involving specific hypothalamic nuclei and brain stem regions. These neural circuits mediate many of the effects of the adipocyte-derived hormone leptin and gut-derived hormone ghrelin. The former is strongly anorexigenic while the latter is the only orexigenic agent active when administered by a peripheral route. Abnormal regulation of these 2 antagonistic regulatory peptides in patients with schizophrenia could play a role in the impairment in the regulation of food intake and energy balance. This bibliographical analysis aims to compare 27 prospective and cross-sectional studies published on circulating leptin and ghrelin levels during acute and chronic administration of antipsychotics treatment, especially atypical ones. Fasting morning leptin levels of schizophrenic patients increase rapidly in the first 2 weeks after atypical antipsychotic (AAP) treatment (mostly olanzapine and clozapine) and remain somehow elevated after that period up to several months. On the contrary, conventional antipsychotics (such as haloperidol) do not interfere with leptin levels. In contrast to leptin, fasting morning ghrelin levels decrease during the first few weeks after the beginning of AAPs treatment while they increase in the longer run. Surprisingly, body weight gain and correlations between the variation of these 2 peptides and adiposity and metabolism-related parameters such as the body mass index and abdominal perimeter were not systematically considered. Finally, an objective evaluation of feeding behavior during antipsychotic treatment remains to be determined.