The time-dependent change of insulin secretion in schizophrenic patients treated with olanzapine

Cevimeline co-treatment attenuates olanzapine-induced metabolic disorders via modulating hepatic M3 muscarinic receptor: AMPKα signalling pathway in female rats

BACKGROUND

Olanzapine is one of the most commonly used antipsychotic drugs; however, its metabolic disorders are the main obstacle in the clinic. Olanzapine is a potent antagonist of the M3 acetylcholine muscarinic receptor (M3R), while the downregulated hepatic M3R-AMPKα signalling pathway is involved in metabolic disorders.

AIM

This study investigated the effects of chronic co-treatment with cevimeline (an agonist of M3Rs) in attenuating olanzapine-induced metabolic disorders and the underlying mechanisms.

METHODS

Forty-eight adult female Sprague-Dawley rats were treated orally with olanzapine (2 mg/kg, 3 times/day (t.i.d.)) and/or cevimeline (9 mg/kg, t.i.d.), or control (vehicle) for 9 weeks.

RESULTS

Cevimeline co-treatment significantly attenuated olanzapine-induced body weight gain and glucolipid metabolic disorders. Importantly, cevimeline co-treatment attenuated olanzapine-induced upregulation of M3Rs, while the co-treatment improved olanzapine-induced downregulation of AMPKα in the liver. Cevimeline co-treatment attenuated olanzapine-induced dyslipidaemia by modulating the hepatic M3R-AMPKα downstream pathways. Cevimeline co-treatment also improved lower activated AKT-GSK3β signalling to reverse impairment of glucose metabolism and insulin resistance caused by chronic olanzapine treatment.

CONCLUSION

These results not only support the important role of M3R antagonism and its related AMPKα and downstream pathways in antipsychotic-induced metabolic disorders but also indicate that these pathways might be promising targets for pharmacological intervention to control these side effects caused by antipsychotic therapy.

Metabolic disturbances associated with antipsychotic drug treatment in patients with schizophrenia: State-of-the-art and future perspectives

Metabolic disturbances and obesity are major cardiovascular risk factors in patients with schizophrenia, resulting in a higher mortality rate and shorter life expectancy compared with those in the general population. Although schizophrenia and metabolic disturbances may share certain genetic or pathobiological risks, antipsychotics, particularly those of second generation, may further increase the risk of weight gain and metabolic disturbances in patients with schizophrenia. This review included articles on weight gain and metabolic disturbances related to antipsychotics and their mechanisms, monitoring guidelines, and interventions. Nearly all antipsychotics are associated with weight gain, but the degree of the weight gain varies considerably. Although certain neurotransmitter receptor-binding affinities and hormones are correlated with weight gain and specific metabolic abnormalities, the precise mechanisms underlying antipsychotic-induced weight gain and metabolic disturbances remain unclear. Emerging evidence indicates the role of genetic polymorphisms associated with antipsychotic-induced weight gain and antipsychotic-induced metabolic disturbances. Although many guidelines for screening and monitoring antipsychotic-induced metabolic disturbances have been developed, they are not routinely implemented in clinical care. Numerous studies have also investigated strategies for managing antipsychotic-induced metabolic disturbances. Thus, patients and their caregivers must be educated and motivated to pursue a healthier life through smoking cessation and dietary and physical activity programs. If lifestyle intervention fails, switching to another antipsychotic drug with a lower metabolic risk or adding adjunctive medication to mitigate weight gain should be considered. Antipsychotic medications are essential for schizophrenia treatment, hence clinicians should monitor and manage the resulting weight gain and metabolic disturbances.

A potential probiotic bacterium for antipsychotic-induced metabolic syndrome: mechanisms underpinning how Akkermansia muciniphila subtype improves olanzapine-induced glucose homeostasis in mice

BACKGROUND

Olanzapine (OLZ) is one of the most effective atypical antipsychotics but is associated with severe metabolic side effects, in which the gut microbiota plays an important role. Akkermansia muciniphila (A. muciniphila; Akk), a Gram-negative anaerobic bacterium in the intestine, can potentially improve metabolic syndrome.

OBJECTIVE

This study investigated the effect and underlying mechanisms of an A. muciniphila subtype (A. muciniphila^sub; Akk^sub) on OLZ-induced metabolic dysfunction in lean and obese mice.

METHODS

C57BL/6 female mice were fed a high-fat diet to induce obesity or normal chow for 8 weeks before OLZ treatment for 16 weeks. During the treatment period, mice in each group were orally administrated A. muciniphila^sub. Weight gain, glucose and lipid metabolism, and inflammation were evaluated.

RESULTS

A. muciniphila^sub decreased OLZ-related weight gain only at week 16 in lean mice and significantly alleviated OLZ-induced hyperglycemia irrespective of diet. This was accompanied by reduced levels of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK)-key enzymes in hepatic gluconeogenesis-and OLZ-associated insulin resistance. Moreover, OLZ-induced increases in serum interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels were improved by A. muciniphila^sub in both obese and lean mice. OLZ did not increase serum lipid levels or hepatic fat accumulation.

CONCLUSIONS

A. muciniphila^sub improves OLZ-related hyperglycemia via regulation of G6Pase and PEPCK levels and insulin resistance. Moreover, A. muciniphila^sub alleviates systemic inflammation caused by OLZ. A. muciniphila^sub is a promising probiotic treatment for OLZ-induced metabolic dysfunction.

Second-Generation Antipsychotic Drugs for Patients with Schizophrenia: Systematic Literature Review and Meta-analysis of Metabolic and Cardiovascular Side Effects

Background and Objectives

Second-generation antipsychotics (SGAs) for schizophrenia show different risk profiles, whose evidence has been evaluated through comparative reviews on randomized controlled trials (RCTs) and observational studies.

Methods

We performed a systematic review and meta-analysis of weight gains, metabolic and cardiovascular side effects of SGAs, relying on both RCTs and observational studies, by comparing variations between the start of treatment and the end of follow-up. The systematic review refers to papers published from June 2009 to November 2020. PRISMA criteria were followed. No restrictions on heterogeneity level have been considered for meta-analysis. A test for the summary effect measure and heterogeneity (I² metric) was used.

Results

Seventy-nine papers were selected from 3076 studies (61% RCTs, 39% observational studies). Olanzapine and risperidone reported the greatest weight gain and olanzapine the largest BMI increase. Paliperidone showed the highest increase in total cholesterol, but is the only drug reporting an increase in the HDL cholesterol. Quetiapine XR showed the highest decrease in fasting glucose. Lurasidone showed the lowest increase in body weight and a reduction in BMI and was also the only treatment reporting a decrease in total cholesterol and triglycerides. The highest increase in systolic and diastolic blood pressure was reported by quetiapine XR.

Conclusions

Despite some limitations (differences in the mean dosages per patient and other side effects not included) this paper provides the first complete meta-analysis on SGAs in variations on metabolic risk profile between start of treatment and end of follow-up, with useful results for clinical practice and possibly for future economic evaluation studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40261-021-01000-1.

Effects of olanzapine treatment on lipid profiles in patients with schizophrenia: a systematic review and meta-analysis

Olanzapine-induced dyslipidemia significantly increases the risk of cardiovascular disease in patients with schizophrenia. However, the clinical features of olanzapine-induced dyslipidemia remain hitherto unclear because of inconsistencies in the literature. This meta-analysis thus investigated the effects of olanzapine treatment on lipid profiles among patients with schizophrenia. Studies of the effects of olanzapine on lipids were obtained through the PubMed, Web of science, The Cochrane Library and Embase databases (up to January 1, 2020). Twenty-one studies and 1790 schizophrenia patients who received olanzapine therapy were included in our analysis. An olanzapine-induced increase was observed in plasma triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels in patients with schizophrenia (all P < 0.05). Moreover, the time points analyzed included the following: baseline, 4 weeks, 6 weeks, 8 weeks, 12 weeks, and ≥ 24 weeks (data of ≥ 24 weeks were integrated). The significant elevation of TG, TC, and LDL-C was observed in patients with schizophrenia already by 4 weeks of olanzapine therapy (all P < 0.05), with no obvious changes observed in high-density lipoprotein cholesterol (HDL-C) (P > 0.05). In conclusion, olanzapine-induced dyslipidemia, characterized by increased TG, TC, and LDL-C levels, was observed in patients with schizophrenia already by 4 weeks of olanzapine treatment.

Mechanochemical synthesis of drug–drug and drug–nutraceutical multicomponent solids of olanzapine

Drug–drug and drug–nutraceutical multicomponent solids of an antipsychotic drug olanzapine (OLN) are prepared using mechanochemistry.

Early prediction of olanzapine-induced weight gain for schizophrenia patients

The aim of this study was to determine whether weight changes at week 2 or other factors predicted weight gain at week 6 for schizophrenia patients receiving olanzapine. This study was the secondary analysis of a six-week trial for 94 patients receiving olanzapine (5 mg/d) plus trifluoperazine (5 mg/d), or olanzapine (10 mg/d) alone. Patients were included in analysis only if they had completed the 6-week trial (per protocol analysis). Weight gain was defined as a 7% or greater increase of the patient's baseline weight. The receiver operating characteristic curve was employed to determine the optimal cutoff points of statistically significant predictors. Eleven of the 67 patients completing the 6-week trial were classified as weight gainers. Weight change at week 2 was the statistically significant predictor for ultimate weight gain at week 6. A weight change of 1.0 kg at week 2 appeared to be the optimal cutoff point, with a sensitivity of 0.92, a specificity of 0.75, and an AUC of 0.85. Using weight change at week 2 to predict weight gain at week 6 is favorable in terms of both specificity and sensitivity. Weight change of 1.0 kg or more at 2 weeks is a reliable predictor.

Let's get physical: improving the medical care of people with severe mental illness

There is clear evidence of increased medical comorbidity and related mortality in people with severe mental illness, despite numerous guidelines for managing medical conditions in this population. This article assesses inequalities in medical treatment and preventive healthcare received by psychiatric patients compared with the general population. It considers whether the medical care provided is adequate and whether published guidelines improve it. Mental health specialists, general practitioners and hospital specialists appear to deliver poorer than average medical care for this vulnerable population. Implementation of physical healthcare guidelines is incomplete and the guidelines must be matched with resources to address this deficit.

Psychosocial Services for Individuals With Serious Mental Illness/Severe Emotional Disturbance: Clinical Practice Guideline Toolkit

This article presents a short, easy-to-use guideline for clinicians working with people with serious mental illness, particularly those with schizophrenia, schizoaffective disorder, delusional disorders, other psychotic disorders, or depression with significant impact on functioning, and may be of use for those working with individuals with bipolar disorder. This guideline is not meant to supplant the more detailed, excellent clinical practice guidelines that have been developed and published. Rather, the charts and explanation presented here are designed as a step-by-step tool that clinicians can use to ensure they are following the most appropriate course of action and providing the best psychosocial rehabilitation services possible for persons with these disorders. Program managers can use this tool to evaluate the processes used in their system to ensure that appropriate services are offered for the individuals in their care. This guideline is also not meant as a substitute for comprehensive training in the practice of assessment and treatment for individuals with serious mental illness. Very little detail is provided about the disorders, appropriate assessments, and interventions because clinicians providing services to people with these disorders should have received the specialized training necessary to appropriately deliver the services needed by these individuals.

Mechanisms underlying metabolic disturbances associated with psychosis and antipsychotic drug treatment

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

Metformin in prevention and treatment of antipsychotic induced weight gain: a systematic review and meta-analysis

BACKGROUND

Most antipsychotics are associated with weight gain and other metabolic complications. Several randomized trials have shown metformin to be effective, but this still hasn't been included in clinical guidelines on managing antipsychotic induced weight gain.

METHODS

All double blind placebo controlled trials assessing the efficacy of metformin in the treatment of antipsychotic induced weight gain were included. Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE were searched for the period January 2000-December 2015. Meta-analysis was carried out using the random effects model.

RESULTS

Meta analysis of 12 published studies with a total of 743 patients found that in patients treated with antipsychotics, metformin treatment resulted in significantly better anthropometric and metabolic parameters than placebo. The mean change in weight was -3.27 kg (95 % CI -4.66 to -1.89) (Z = 4.64, p < 0.001). Metformin compared to placebo resulted in significant reduction in BMI [-1.13 kg/m² (95 % CI -1.61 to -0.66)] and insulin resistance index [-1.49 (95 % CI -2.40 to -0.59)] but not fasting blood sugar [-2.48 mg/dl (95 % CI -5.54 to 0.57].

CONCLUSION

This meta-analysis confirms that metformin is effective in treating antipsychotic induced weight gain in patients with schizophrenia or schizoaffective disorder.

Brain stem as a target site for the metabolic side effects of olanzapine

Olanzapine, an atypical antipsychotic, is widely prescribed for the treatment of schizophrenia and bipolar disorder despite causing undesirable metabolic side effects. A variety of mechanisms and brain sites have been proposed as contributors to the side effects; however, the role of the dorsal motor nucleus of the vagus nerve (DMV), which plays a crucial role in the regulation of subdiaphragmatic organs and thus governs energy and glucose homeostasis, is largely unknown. Identifying the effect of olanzapine on the excitability of DMV neurons in both sexes is thus crucial to understanding possible underlying mechanisms. Whole cell patch-clamp electrophysiological recordings were conducted in stomach- and liver-related DMV neurons identified with retrograde viral tracers and in random DMV neurons. The effect of olanzapine on the neuronal excitability of DMV neurons both in male and female mice was established. Our data demonstrate that olanzapine hyperpolarizes the DMV neurons in both sexes and this effect is reversible. The hyperpolarization is associated with decreased firing rate and input resistance. Olanzapine also decreases the excitability of a subset of stomach- and liver-related DMV neurons. Our study demonstrates that olanzapine has a powerful effect on DMV neurons in both sexes, indicating its ability to reduce vagal output to the subdiaphragmatic organs, which likely contributes to the metabolic side effects observed in both humans and experimental models. These findings suggest that the metabolic side effects of olanzapine may partially originate in the DMV.

[Metabolic Control, Evaluation and Follow-up Interventions in Patients With Schizophrenia]

OBJECTIVES

To determine the laboratory tests, related to metabolic risk that should be practiced to adult patients diagnosed with schizophrenia. To assist the clinician decision-making process about complementary diagnostic evaluation strategies in adult diagnosed with schizophrenia.

METHODS

A clinical practice guideline was elaborated under the parameters of the Methodological Guide of the Ministerio de Salud y Protección Social to identify, synthesize and evaluate the evidence and make recommendations about the treatment and follow-up of adult patients with schizophrenia. The evidence of NICE guide 82 was adopted and updated. The evidence was presented to the Guideline Developing Group and recommendations, employing the GRADE system, were produced.

RESULTS

The risk of overall mortality in schizophrenia is higher than in the general population excluding suicide. Results related with mortality associated to antipsychotics showed contradictory results. Metabolic outcomes showed a higher incidence and association with schizophrenia and treatment with antipsychotics (AP). The diagnosis of dyslipidemia in men with schizophrenia appears to be lower in comparison with the general population. However, changes in weight, blood sugar levels, HDL cholesterol and triglycerides are influenced by the use of antipsychotics in general there is a higher risk of developing diabetes mellitus in adults with schizophrenia.

CONCLUSION

Based on the evidence found a plan was formulated for the evaluation of physiological and paraclinical variables during and before the management with AP in adult diagnosed with schizophrenia. The overall quality of evidence is low considering that most of the reports come from observational studies that have risk of bias and some designs have methodological limitations.

Olanzapine induced biochemical and histopathological changes after its chronic administration in rats

Objective: Olanzapine is a second generation antipsychotic acting mainly as a dopamine D₂ and serotonine 5-HT₂ receptors antagonist prescribed in the treatment of schizophrenia and various other psychiatric illnesses. Even though olanzapine is widely used in psychiatry, its effects on the architecture of pancreas, liver and kidneys are little known. The histology of pancreas especially has never been studied. For these reasons, the current study was designed to elucidate the toxic effects of chronic administration of olanzapine on pancreas, liver and kidneys and the enzymes released by these tissues in an escalating dose manner. Methods: Fourteen male rats were divided into two groups equally, the olanzapine group and the controls. Olanzapine was administered in a dose of 5 mg/kg/d for the first eight weeks, 10 mg/kg/d for next four weeks and 15 mg/kg/d through the last two week period of 14 weeks experiment. The controls received acidified saline only. Both the groups received restricted diet (20 g/12 h). The body weight and level of random blood sugar (RBS) were measured on a weekly basis. The levels of lipase, amylase, alanine transaminase (ALT) and aspartate transaminase (AST) were determined terminally. At the end of the experiment, the tissues were dissected out for histopathological evaluation. Results: Significant loss in body weight, change in the level of random blood sugar (^∗∗P < 0.05, ^∗∗∗P < 0.001) and significant rise in amylase and lipase levels (^∗P < 0.05, ^∗∗∗P < 0.001) were observed. However, the same treatment has shown no significant change in the levels of alanine and aspartate transaminases (P > 0.05). The pancreas has shown derangement of beta cells and fibrotic growth. A mild to moderate focal increase in glomerular cellularity, cellular proliferation and glomerular capsules with negligible basement membranes were observed in the kidneys. No changes were observed in the architecture of the liver. Conclusion: The findings of this study indicated that the incidence of adverse effects associated with olanzapine could be prevented/alleviated/delayed by allowing restricted diet.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Metabolomic profiling of schizophrenia patients at risk for metabolic syndrome

Second-generation antipsychotics (SGAs) are commonly used to treat schizophrenia. However, SGAs cause metabolic disturbances that can manifest as metabolic syndrome (MetS) in a subset of patients. The causes for these metabolic disturbances remain unclear. We performed a comprehensive metabolomic profiling of 60 schizophrenia patients undergoing treatment with SGAs that puts them at high (clozapine, olanzapine), medium (quetiapine, risperidone), or low (ziprasidone, aripiprazole) risk for developing MetS, compared to a cohort of 20 healthy controls. Multiplex immunoassays were used to measure 13 metabolic hormones and adipokines in plasma. Mass spectrometry was used to determine levels of lipids and polar metabolites in 29 patients and 10 controls. We found that levels of insulin and tumor necrosis factor alpha (TNF-α) were significantly higher (p < 0.005) in patients at medium and high risk for MetS, compared to controls. These molecules are known to be increased in individuals with high body fat content and obesity. On the other hand, adiponectin, a molecule responsible for control of food intake and body weight, was significantly decreased in patients at medium and high risk for MetS (p < 0.005). Further, levels of dyacylglycerides (DG), tryacylglycerides (TG) and cholestenone were increased, whereas α-Ketoglutarate and malate, important mediators of the tricarboxylic acid (TCA) cycle, were significantly decreased in patients compared to controls. Our studies suggest that high- and medium-risk SGAs are associated with disruption of energy metabolism pathways. These findings may shed light on the molecular underpinnings of antipsychotic-induced MetS and aid in design of novel therapeutic approaches to reduce the side effects associated with these drugs.

Olanzapine in Chinese patients with schizophrenia or bipolar disorder: a systematic literature review

BACKGROUND

Despite the burden of schizophrenia and bipolar disorder in the Chinese population, country-specific data to guide practitioners regarding antipsychotic therapy are lacking. The primary aim of this systematic review was to examine evidence of the efficacy, effectiveness, and safety of olanzapine in Chinese populations.

METHODS

A systematic literature search was conducted using databases covering international and Chinese core journals using search terms related to schizophrenia and bipolar disorder, specified countries (People's Republic of China, Hong Kong, Taiwan), and olanzapine treatment. Following initial screening, inclusion and exclusion criteria were applied to the search results to identify relevant studies from which data were extracted.

RESULTS

A total of 489 publications were retrieved and 61 studies were identified for inclusion. Most studies were related to schizophrenia (n=54), with six studies related to bipolar disorder and one study related to both conditions. The quality of study methods and reporting in international journals was noticeably better than in Chinese language journals. Most studies included relatively small patient populations and were of short duration. The efficacy of olanzapine in Chinese populations was confirmed by multiple comparative and noncomparative studies that found statistically significant reductions in symptom measures in studies conducted for ≥6 weeks (schizophrenia) or ≥3 weeks (bipolar disorder). Findings related to effectiveness (treatment discontinuation, quality of life, and neurocognitive improvements) were generally consistent with those observed in non-Chinese populations. No new safety signals specific for Chinese populations were raised for olanzapine.

CONCLUSION

Chinese and non-Chinese populations with schizophrenia or bipolar disorder treated with olanzapine display broadly similar responses. Differences between these populations, especially in relation to the relative efficacy of olanzapine versus other antipsychotics, may warrant further investigation via studies incorporating both populations. Use of local data to provide evidence for practice guidelines should be encouraged, and may promote ongoing improvements in the quality of research and study reporting.

Almost all antipsychotics result in weight gain: a meta-analysis

Introduction

Antipsychotics (AP) induce weight gain. However, reviews and meta-analyses generally are restricted to second generation antipsychotics (SGA) and do not stratify for duration of AP use. It is hypothesised that patients gain more weight if duration of AP use is longer.

Method

A meta-analysis was conducted of clinical trials of AP that reported weight change. Outcome measures were body weight change, change in BMI and clinically relevant weight change (7% weight gain or loss). Duration of AP-use was stratified as follows: ≤6 weeks, 6–16 weeks, 16–38 weeks and >38 weeks. Forest plots stratified by AP as well as by duration of use were generated and results were summarised in figures.

Results

307 articles met inclusion criteria. The majority were AP switch studies. Almost all AP showed a degree of weight gain after prolonged use, except for amisulpride, aripiprazole and ziprasidone, for which prolonged exposure resulted in negligible weight change. The level of weight gain per AP varied from discrete to severe. Contrary to expectations, switch of AP did not result in weight loss for amisulpride, aripiprazole or ziprasidone. In AP-naive patients, weight gain was much more pronounced for all AP.

Conclusion

Given prolonged exposure, virtually all AP are associated with weight gain. The rational of switching AP to achieve weight reduction may be overrated. In AP-naive patients, weight gain is more pronounced.

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

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

Olanzapine-induced changes in glucose metabolism are independent of the melanin-concentrating hormone system

Atypical antipsychotic drugs such as Olanzapine (Ola) induce weight gain and metabolic changes associated with the development of type 2 diabetes. The mechanisms underlying these undesired side-effects are currently unknown. Chagnon et al. showed that the common allele rs7973796 of the prepro-melanin-concentrating hormone (PMCH) gene is associated with a greater body mass index in Ola-treated schizophrenic patients. As PMCH encodes for the orexigenic neuropeptide melanin-concentrating hormone (MCH), it was hypothesized that MCH is involved in Ola-induced metabolic changes. We have recently reported that the intragastric infusion of Ola results in hyperglycaemia and insulin resistance in male rats. In order to test in vivo the possible involvement of the PMCH gene in the pathogenesis of Ola side-effects, we administered Ola intragastrically in wild-type (WT) and PMCH knock-out (KO) rats. Our results show that glucose and corticosterone levels, as well as endogenous glucose production, are elevated by the infusion of Ola in both WT and KO animals. Thus, the lack of MCH does not seem to affect the acute effects of Ola on glucose metabolism. On the other hand, these effects might be obliterated by compensatory changes in other hypothalamic systems. In addition, possible modulatory effects of the MCH KO on the long term effects of Ola, i.e. increased adiposity, body weight gain, have not been investigated yet.

A meta-analysis of cardio-metabolic abnormalities in drug naïve, first-episode and multi-episode patients with schizophrenia versus general population controls

A meta-analysis was conducted to explore the risk for cardio-metabolic abnormalities in drug naïve, first-episode and multi-episode patients with schizophrenia and age- and gender- or cohort-matched general population controls. Our literature search generated 203 relevant studies, of which 136 were included. The final dataset comprised 185,606 unique patients with schizophrenia, and 28 studies provided data for age- and gender-matched or cohort-matched general population controls (n=3,898,739). We found that multi-episode patients with schizophrenia were at increased risk for abdominal obesity (OR=4.43; CI=2.52-7.82; p<0.001), hypertension (OR=1.36; CI=1.21-1.53; p<0.001), low high-density lipoprotein cholesterol (OR=2.35; CI=1.78-3.10; p<0.001), hypertriglyceridemia (OR=2.73; CI=1.95-3.83; p<0.001), metabolic syndrome (OR=2.35; CI=1.68-3.29; p<0.001), and diabetes (OR=1.99; CI=1.55-2.54; p<0.001), compared to controls. Multi-episode patients with schizophrenia were also at increased risk, compared to first-episode (p<0.001) and drug-naïve (p<0.001) patients, for the above abnormalities, with the exception of hypertension and diabetes. Our data provide further evidence supporting WPA recommendations on screening, follow-up, health education and lifestyle changes in people with schizophrenia.

Effects of antipsychotic medications on appetite, weight, and insulin resistance

Although clozapine, olanzapine, and other atypical antipsychotic drugs (APDs) have fewer extrapyramidal side effects, they have serious metabolic side effects such as substantial weight gain, intra-abdominal obesity, and type 2 diabetes mellitus. Given that most patients with mental disorders face chronic, even life-long, treatment with APDs, the risks of weight gain/obesity and other metabolic symptoms are major considerations for APD maintenance treatment. This review focuses on the effects of APDs on weight gain, appetite, insulin resistance, and glucose dysregulation, and the relevant underlying mechanisms that may be help to prevent and treat metabolic side effects caused by APD therapy.

Metabolic syndrome in schizophrenia

To review the data with respect to prevalence of metabolic syndrome (MetS) and its correlates in schizophrenia. For this review, electronic search engines PUBMED, Sciencedirect, and Google Scholar were used. Available data suggests that most of the studies have been of cross-sectional design. Prevalence rates of MetS have varied from 11% to 69% in medicated patients, and 4-26% in drug naive patients in cross-sectional evaluations. Longitudinal studies have shown the prevalence rates to range from 0% to 14% at the baseline in drug naive patients, which increase to as high as 52.4% by 3 months of antipsychotic medication treatment. The prevalence rates of MetS in patients with schizophrenia are much higher than that seen in general population or healthy controls. Though there is no causal association with any demographic or clinical variables, the risk increases with increase in age. Among antipsychotics, there seems to be an association between MetS and atypical antipsychotics like clozapine and olanzapine. Therefore, the psychiatrists should be more vigilant regarding the presence of MetS in these high risk groups. Research on biological correlates of MetS in schizophrenia is still in its primitive stage, however, these is some evidence to suggest an association of MetS with adiponectin levels, hematological indices, methylenetetrahydrofolate reductase (MTHFR) and Alpha-1A adrenergic receptor (ADRA1A) gene. These areas hold promise, and targeting these with appropriate interventions may help us to prevent the occurrence of MetS in patients with schizophrenia in future.

Determination of olanzapine and N-desmethyl-olanzapine in plasma using a reversed-phase HPLC coupled with coulochemical detection: correlation of olanzapine or N-desmethyl-olanzapine concentration with metabolic parameters

BACKGROUND

Olanzapine (OLZ) is one of the most prescribed atypical antipsychotic drugs but its use is associated with unfavorable metabolic abnormalities. N-desmethyl-olanzapine (DMO), one of the OLZ metabolites by CYP1A2, has been reported to have a normalizing action on metabolic abnormalities, but this remains unclear. Our aim was to explore the correlation between the concentrations of OLZ or DMO with various metabolic parameters in schizophrenic patients.

METHODS

The chromatographic analysis was carried out with a solvent delivery system coupled to a Coulochem III coulometric detector to determine OLZ and DMO simultaneously in OLZ-treated patients. The correlation between the concentration of OLZ or DMO and the metabolic parameters was analyzed by the Spearman rank order correlation method (r s).

PRINCIPAL FINDINGS

The established analytical method met proper standards for accuracy and reliability and the lower limitation of quantification for each injection of DMO or OLZ was 0.02 ng. The method was successfully used for the analysis of samples from nonsmoking patients (n = 48) treated with OLZ in the dosage range of 5-20 mg per day. There was no correlation between OLZ concentrations and tested metabolic parameters. DMO concentrations were negatively correlated with glucose (r s = -0.45) and DMO concentrations normalized by doses were also negatively correlated with insulin levels (r s = -0.39); however, there was a marginally positive correlation between DMO and homocysteine levels (r s = +0.38).

CONCLUSIONS

The observed negative correlations between levels of DMO and glucose or insulin suggest a metabolic normalization role for DMO regardless of its positive correlation with a known cardiovascular risk factor, homocysteine. Additional studies of the mechanisms underlying DMO's metabolic effects are warranted.

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

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

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

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

Atypical antipsychotic-induced weight gain: insights into mechanisms of action

Prescriptions for second-generation antipsychotics (SGAs) have surpassed those for first-generation agents in the treatment of schizophrenia and bipolar disorder. While SGAs have the benefit of a much reduced risk of causing movement disorders, they have been associated with weight gain and metabolic effects. These adverse reactions are not uncommon, and threaten to have a significant impact on the patient's health over the long-term treatment that the patient requires. Currently, the aetiology of these effects is not known. This article reviews the data exploring the weight gain phenomenon. The literature was reviewed from searches of PubMed and the references of major articles in the field. The SGAs present a heterogeneous risk for weight gain. In addition, different individuals receiving the same drug can exhibit substantially different weight changes. This pattern suggests that a group of factors are associated with the weight gain phenomenon rather than a single mechanism. Coupled with the genetic profile that the patient brings to the treatment, the risk for SGA-induced weight gain will be different for different drugs and different individuals. Targets for exploration of the weight gain phenomenon include receptor interactions involving serotonin, histamine, dopamine, adrenergic, cannabinoid and muscarinic receptors. The association of SGA-induced weight gain and the role of orexigenic and anorexigenic peptides are reviewed. Also, a brief discussion of genetic factors associated with SGA-induced weight gain is presented, including that of the serotonin 5-HT(2C) receptor gene (HTR2C) and the cannabinoid 1 receptor gene (CNR1). The most promising data associated with SGA-induced weight gain include investigations of the histamine H(1), 5-HT(2A), 5-HT(2C), muscarinic M(3) and adrenergic receptors. In addition, work in the genetic area promises to result in a better understanding of the variation in risk associated with different individuals.

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

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

Intermittent treatment with olanzapine causes sensitization of the metabolic side-effects in rats

The second generation antipsychotic drugs are effective treatments for psychotic disorders. Many of these compounds, including the drug olanzapine, have been associated with metabolic side-effects, including weight gain, impaired glucose tolerance and insulin resistance, which increase the risk of developing cardiometabolic disorders. Rodent models of olanzapine-induced metabolic side-effects have been used to study the physiology of these effects, but only at a single time point after drug treatment. The purpose of the present study was to examine longitudinal changes with chronic antipsychotic drug treatment. Adult female rats were treated with either olanzapine (15 mg/kg) or vehicle for five consecutive days each week, followed by a 48 h washout period. Animals were then challenged with either olanzapine (15 mg/kg) or vehicle, and fasting glucose and insulin values were recorded, as well as glucose clearance in the glucose tolerance test. Treatment with olanzapine was continued for 10 weeks, with weekly tests of metabolic indices. Rats treated acutely with olanzapine showed both glucose dysregulation and insulin resistance; for the group treated during the week with olanzapine, these effects did not change by the end of ten weeks of treatment. However, in the group of animals challenged only once per week with olanzapine, the metabolic side-effects markedly intensified with the passage of time, whereby glucose intolerance and insulin resistance increased significantly compared to both baseline values and all other treatment groups. This previously unreported sensitization phenomenon represents a novel finding that may have clinical implications for patients receiving intermittent antipsychotic drug dosing or with variable adherence to treatment.

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.