Metformin for weight reduction in non-diabetic patients on antipsychotic drugs: a systematic review and meta-analysis

Multi-omics analysis of the lipid-regulating effects of metformin in a glucose concentration-dependent manner in macrophage-derived foam cells

Metformin has a long history of clinical application and has been shown to have outstanding ability in lowering glucose. Recent advances have further revealed its broad modulatory ability beyond glucose-lowering, expanding the scope of metformin applications. Metformin has now been applied as a viable lipid-lowering strategy in non-hyperglycemic obese patients. However, the benefits and underlying pharmacological mechanisms of metformin administration in non-hyperglycemic populations remain to be explained. Our study aimed to systematically investigate the differences in the lipid-lowering function and pharmacological mechanisms of metformin in high- and low-sugar conditions to facilitate the development of individualized metformin use regimens for different clinical patients. We constructed macrophage-derived foam cell models in vitro for subsequent analysis. ORO results showed that metformin significantly reduced lipid accumulation in macrophages in both high and low glucose environments, but the lipid decline was higher in the high glucose environment. By mutual validation and joint analysis of transcriptomics and metabolomics, significant differences in metformin transcriptional and metabolic patterns existed among high and normal glucose environments. The significant alterations of genes such as DGKA, LPL, DGAT2 and lipid metabolites such as LysPA and LysPC partially explained the glucose-dependent pharmacological function of metformin. In conclusion, our study confirmed that the lipid-lowering effect of metformin depends on the extracellular glucose concentration, and systematically studied the molecular mechanism of metformin in different glycemic environments, which provides a certain reference value for the subsequent in-depth study and clinical application.

Central Neuromodulators in Irritable Bowel Syndrome: Why, How, and When

Irritable bowel syndrome (IBS) is responsive to treatments using central neuromodulators. Central neuromodulators work by enhancing the synaptic transmission of 5-hydroxytryptamine, noradrenalin, and dopamine, achieving a slower regulation or desensitization of their postsynaptic receptors. Central neuromodulators act on receptors along the brain-gut axis, so they are useful in treating psychiatric comorbidities, modifying gut motility, improving central downregulation of visceral signals, and enhancing neurogenesis in patients with IBS. Choosing a central neuromodulator for treating IBS should be according to the pharmacological properties and predominant symptoms. The first-line treatment for pain management in IBS is using tricyclic antidepressants. An alternative for pain management is the serotonin and noradrenaline reuptake inhibitors. Selective serotonin reuptake inhibitors are useful when symptoms of anxiety and hypervigilance are dominant but are not helpful for treating abdominal pain. The predominant bowel habit is helpful when choosing a neuromodulator to treat IBS; selective serotonin reuptake inhibitors help constipation, not pain, but may cause diarrhea; tricyclic antidepressants help diarrhea but may cause constipation. A clinical response may occur in 6-8 weeks, but long-term treatment (usually 6-12 months) is required after the initial response to prevent relapse. Augmentation therapy may be beneficial when the therapeutic effect of the first agent is incomplete or associated with side effects. It is recommended to reduce the dose of the first agent and add a second complementary treatment. This may include an atypical antipsychotic or brain-gut behavioral treatment. When tapering central neuromodulators, the dose should be reduced slowly over 4 weeks but may take longer when discontinuation effects occur.

Are probiotics effective in reducing the metabolic side effects of psychiatric medication? A scoping review of evidence from clinical studies

The psychopharmacological treatment of patients with schizophrenia or depression is often accompanied by serious side effects. In particular, the clinical findings of weight gain are worrying, as this side effect can lead to various medical sequelae in the future. However, the treatment of metabolic changes in psychiatric patients is often neglected or unsuccessful. An improved knowledge of possible therapeutic approaches is needed. The aim of this study was to provide an overview of the utilisation and effectiveness of probiotics in reducing weight gain in patients with severe mental illness. A scoping review of studies published until 15 June 2022 was conducted to identify studies using probiotics in people with schizophrenia or depression. We systematically searched the databases EMBASE, PubMed (MEDLINE), Web of Science and SCOPUS with a predefined search string. In addition, reference lists of relevant publications were examined for additional studies. The studies were assessed by two reviewers. The primary outcomes were weight-related measurements. The secondary outcomes were metabolic blood parameters and gut microbiota. Four studies ultimately met the inclusion criteria. Two studies in which probiotics were administered did not find significant effects on pharmacologically induced weight gain. The other two studies examined the effects of synbiotics (a combination of probiotics and prebiotics). Interestingly, less weight gain was observed in individuals with this combined intervention. Adjustments in diet can be helpful and are generally well-accepted interventions in the fight against pharmacologically induced weight gain. The clinical use of probiotics and prebiotics (or synbiotics) as dietary interventions may represent a promising additional strategy in this regard. However, the few studies available showed no clear conclusions.

Metformin use and the risk of total knee replacement among diabetic patients: a propensity-score-matched retrospective cohort study

Metformin has been shown to modulate meta-inflammation, an important pathogenesis in knee osteoarthritis (OA). The study aimed to test the association between regular metformin use with total knee replacement (TKR) in patients with diabetes. This is a retrospective study with electronic records retrieved in Hong Kong public primary care. Patients with diabetes aged ≥ 45 who visited during 2007 to 2010, were followed up for a four-year period from 2011 to 2014 to determine the incidence of TKR. Propensity score matching based on age, sex, co-medications and chronic conditions was conducted to adjust for confounding. Cox regression was implemented to examine the association between metformin use and TKR. In total, 196,930 patients were eligible and 93,330 regular metformin users (defined as ≥ 4 prescriptions over the previous year) and non-users were matched. Among 46,665 regular users, 184 TKRs were conducted, 17.1% fewer than that among non-users. Cox regression showed that regular metformin users had a 19%-lower hazard of TKR [hazard ratio (HR) = 0.81, 95% confidence interval: 0.67 to 0.98, P = 0.033], with a dose–response relationship. Findings suggest a potential protective effect of metformin on knee OA progression and later TKR incidence among diabetic patients.

Metformin use is associated with low risk of case fatality and disability rates in first-ever stroke patients with type 2 diabetes

Background:

To assess the effectiveness of metformin treatment on long-term outcomes in first-ever stroke patients with type 2 diabetes mellitus (T2DM) in China.

Methods:

From August to September 2019, all patients with first-ever stroke and T2DM from 232 hospitals in China Mainland were included. The enrolled patients were divided into two groups: the metformin treatment (MT) and the no-metformin treatment (No-MT) groups. All discharged patients would receive a telephone follow-up at 12-month after admission.

Results:

In total, 7587 first-ever stroke patients with T2DM [age: median (IQR) = 66 (57–73) years; 57.35% male] were recruited. Out of those 7587 included patients, 3593 (47.36%) received MT. The in-hospital case fatality rate was lower in the MT group than the No-MT group [MT group versus No-MT group: 1.09% versus 2.30%; absolute difference = −1.75% (95% CI = −2.15 to −1.17%); OR = 0.63 (95% CI = 0.47 to 0.84)]. The 12-month case fatality rate was lower in the MT group than the No-MT group [4.72% versus 8.05%; absolute difference = −4.05% (95% CI = −5.58 to −2.41); OR = 0.69 (95% CI = 0.50 to 0.88)]. The 12-month disability rate was also lower in the MT group than the No-MT group [14.74% versus 19.41%; absolute difference = −5.70% (95% CI = −7.25 to −3.22); OR = 0.83 (95% CI = 0.70 to 0.95)]. Furthermore, the recurrence rate did not differ significantly between the MT and No-MT groups (p = 0.29).

Conclusion:

The study reveals that metformin use in stroke patients with T2DM results in a less severe stroke and lower fatality and disability rates.

The role of metformin in treatment of weight gain associated with atypical antipsychotic treatment in children and adolescents: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Second-generation antipsychotics are associated with significant weight gain. The aim of this systematic review and meta-analysis was to determine the efficacy and safety of metformin for the treatment of weight gain in children and young adults treated with second-generation antipsychotics.

METHODS

We followed PRISMA guidelines to evaluated studies published before March 2020 in Medline, Google Scholar, PubMed, Cochrane library database, annual scientific sessions of the American Psychiatric Association, American Academy of Child and Adolescent, Psychiatry, and American Society of Clinical Psychopharmacology. Studies included compared metformin with the placebo for management of weight gain in children and adolescents taking atypical antipsychotics. Non-randomized studies, animal experiment studies, editorials, and review studies were excluded. Multiple parameters, including change in anthropometric-biochemical parameters, drug discontinuation rate, and side effects among the groups were assessed. The random-effects method was used for meta-analysis.

RESULTS

Four studies with were included in the final analysis (213 patients; metformin: 106; control: 107). After pooled analysis, 12-16 weeks of metformin therapy was associated with a significant reduction in weight [(mean difference (MD): -4.53 lbs, confidence interval (CI): -6.19 to -2.87, p-value < 0.001)], and BMI z score [MD, -0.09, CI: -0.16, -0.03, p-value: 0.004] compared to control. Metformin was also associated with a significant reduction in insulin resistance [MD: -1.38, CI: -2.26 to -0.51, p-value: 0.002]. There were higher odds of nausea-vomiting [OR: 4.07, CI: 1.32-12.54, p-value: 0.02] and diarrhea [OR: 2.93, CI: 1.50-5.71, p-value: 0.002] in the metformin group. However, there was no difference in drug discontinuation rate [OR: 1.45, CI: 0.41-5.06, p-value: 0.56].

CONCLUSION

Metformin may prove beneficial in the treatment of weight gain in children treated with second-generation antipsychotics. The pooled treatment effect showed a significant reduction in BMI Z-score and weight in just 12-16 weeks. The limitations include small sample size, variation in metformin dose, and duration of treatment. This meta-analysis should be interpreted as promising, and further larger studies are warranted before drawing a conclusion.

Twenty-Four Week, Randomized, Double-Blind, Placebo-Controlled Trial of Metformin for Antipsychotic-Induced Weight Gain in Patients with First-Episode Psychosis: A Pilot Study

Excessive weight gain and cardiometabolic dysfunction are common and clinically relevant side effects of antipsychotic medications. In this pilot study, we aimed to establish the feasibility of using metformin and its effectiveness in managing antipsychotic-induced weight gain in patients with first-episode psychosis (FEP) on follow-up with the Singapore Early Psychosis Intervention Programme in a 24-week, randomized, double-blind, placebo-controlled trial, to ascertain the effects of metformin discontinuation on body weight and evaluate the safety and tolerability of metformin. Participants between the ages of 16 and 40 with FEP assessed as clinically stable and who had gained ≥5% of their pre-drug weight after initiation of the antipsychotic treatment were recruited from outpatient clinics between April 2015 and April 2018. Seventeen participants met all the inclusion criteria and were randomized to receive metformin (n = 8) or the placebo (n = 9) at Week 0, with follow up assessments at Weeks 3, 6, 12, 24, and 36. Metformin was generally well-tolerated. Participants in the metformin arm were able to control their weight better than participants receiving the placebo, an effect that did not persist after discontinuation. Our results support the use of metformin as a safe and tolerable weight control measure in a typical outpatient sample of young people with FEP.

Pharmacotherapeutic options for weight regain after bariatric surgery

PURPOSE OF REVIEW

We sought to critically evaluate the recent literature published over the past 3 years on the topic of weight regain after bariatric surgery in children, adolescents, and adults, with an emphasis on clinically- relevant information for pharmacologic treatment of weight regain after metabolic and bariatric surgery.

FINDINGS

There are multiple pharmacotherapeutic agents available to treat obesity in children, adolescents, and adults; these agents have varying efficacy and indications for use and have been studied in a variety of clinical and research scenarios. We present an overview of these findings.

SUMMARY

This review represents a comprehensive compilation of the recently published data on efficacy of anti-obesity pharmacotherapy in the treatment of weight regain after bariatric surgery for children, adolescents, and adults.

Pharmacological Management of Glucose Dysregulation in Patients Treated with Second-Generation Antipsychotics

Fasting hyperglycemia, impaired glucose tolerance, prediabetes, and diabetes are frequently present in patients treated with second-generation antipsychotics (SGAPs) for schizophrenia, bipolar disorder, and other severe mental illnesses. These drugs are known to produce weight gain, which may lead to insulin resistance, glucose intolerance, and metabolic syndrome, which constitute important risk factors for the emergence of diabetes. The aim of this review was to formulate therapeutic guidelines for the management of diabetes in patients treated with SGAPs, based on the association between SGAP-induced weight gain and glucose dysregulation. A  systematic search in PubMed from inception to March 2020 for randomized controlled trials (RCTs) of diabetes or prediabetes in patients treated with SGAPs was performed. PubMed was also searched for the most recent clinical practice guidelines of interventions for co-morbid conditions associated with diabetes mellitus (DM) (arterial hypertension and dyslipidemia), lifestyle interventions and switching from high metabolic liability SGAPs to safer SGAPs. The search identified 14 RCTs in patients treated with SGAPs. Drug therapy using metformin as first-line therapy and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) or perhaps sodium-glucose cotransporter-2 (SGLT2) inhibitors as add-on therapy, might be preferred in these patients as well, as they favorably influence glucose metabolism and body mass index, and provide cardio-renal benefits in general to the DM population, although for the SGLT-2 inhibitors there are no RCTs in this specific patient category so far. Metformin is also useful for treatment of prediabetes. Arterial hypertension should be treated with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and statins should be used for correction of dyslipidemia. The outcome of lifestyle-changing interventions has been disappointing. Switching from clozapine, olanzapine, or quetiapine to lower cardiometabolic-risk SGAPs, like aripiprazole, brexpiprazole, cariprazine, lurasidone, or ziprasidone, has been recommended.

The Impact of Pharmacological and Non-Pharmacological Interventions to Improve Physical Health Outcomes in People With Schizophrenia: A Meta-Review of Meta-Analyses of Randomized Controlled Trials

(Reprinted with permission from World Psychiatry 2019;18:53-66).

The Use of Metformin to Increase the Human Healthspan

Metformin is a safe, effective and useful drug for glucose management in patients with diabetes. However in recent years, more attention has been paid to the possibility of using metformin as an anti-aging drug. It was shown to significantly increase the lifespan in some model organisms and delay the onset of age-associated declines. The current review summarizes advances in clinical research on the potential role of metformin in the field of lifespan and healthspan extension. Growing amounts of evidence from clinical trials suggest that metformin can effectively reduce the risk of many age-related diseases and conditions, including cardiometabolic disorders, neurodegeneration, chronic inflammation and frailty. Metformin also holds promise as a drug that could be repurposed for chemoprevention or adjuvant therapy for certain types of cancer. Moreover, metformin induces autophagy by activation of AMPK and can thus be potentially used to promote heathspan by hormesis-like mechanisms. Although long-term intake of metformin is associated with low risk of adverse events, well-designed clinical trials are still required to uncover the potential use of this drug as a geroprotector.

GDF-15 as a Weight Watcher for Diabetic and Non-Diabetic People Treated With Metformin

Weight gain and obesity are global health concerns contributing to morbidity with increased risks of cardiovascular disease, diabetes, liver steatohepatitis and cancer. Pharmacological therapies or bariatric surgery are often required for those who fail to adhere to diet and lifestyle modifications. Metformin, a widely used antidiabetic agent, seems to have a health benefit beyond its anti-hyperglycemic properties, with few side effects. Emerging evidence shows weight loss to be associated with metformin in both diabetic and non-diabetic individuals. Recently, the growth differentiation factor 15 (GDF-15), a member of the transforming growth factor beta superfamily, has been identified as a key mediator of metformin-induced weight loss. Metformin increases the secretion of GDF-15, which binds exclusively to glial cell-derived neurotrophic factor family receptor alpha-like (GFRAL). This gut-brain cytokine works as a prominent player in reducing food intake and body weight in health and disease, like anorexia nervosa and cancer. Herein, we critically review advances in the understanding of the weight-reducing effects of metformin via the GDF-15 pathway.

Mechanisms of action of metformin with special reference to cardiovascular protection

Management guidelines continue to identify metformin as initial pharmacologic antidiabetic therapy of choice for people with type 2 diabetes without contraindications, despite recent randomized trials that have demonstrated significant improvements in cardiovascular outcomes with newer classes of antidiabetic therapies. The purpose of this review is to summarize the current state of knowledge of metformin's therapeutic actions on blood glucose and cardiovascular clinical evidence and to consider the mechanisms that underlie them. The effects of metformin on glycaemia occur mainly in the liver, but metformin-stimulated glucose disposal by the gut has emerged as an increasingly import site of action of metformin. Additionally, metformin induces increased secretion of GLP-1 from intestinal L-cells. Clinical cardiovascular protection with metformin is supported by three randomized outcomes trials (in newly diagnosed and late stage insulin-treated type 2 diabetes patients) and a wealth of observational data. Initial evidence suggests that cotreatment with metformin may enhance the impact of newer incretin-based therapies on cardiovascular outcomes, an important observation as metformin can be combined with any other antidiabetic agent. Multiple potential mechanisms support the concept of cardiovascular protection with metformin beyond those provided by reduced blood glucose, including weight loss, improvements in haemostatic function, reduced inflammation, and oxidative stress, and inhibition of key steps in the process of atherosclerosis. Accordingly, metformin remains well placed to support improvements in cardiovascular outcomes, from diagnosis and throughout the course of type 2 diabetes, even in this new age of improved outcomes in type 2 diabetes.

Pharmacogenetics of Metformin for Medication-Induced Weight Gain in Autism Spectrum Disorder

Objectives: We recently found that metformin attenuated weight gain due to mixed dopamine and serotonin receptor antagonists, commonly termed atypical antipsychotics, in children and adolescents with autism spectrum disorder (ASD). Previous studies have found that genetic variation predicts response to metformin in diabetes. In this study, we aimed to assess whether response to metformin for weight gain in this population is associated with variants in five genes previously implicated in metformin response in diabetes. Methods: Youth with ASD who experienced significant weight gain while taking mixed receptor antagonist medications were randomly assigned to metformin or placebo for 16 weeks, followed by open-label metformin treatment for 16 weeks. In the 53 participants with available DNA samples, we used a linear, mixed model analysis to assess response in the first 16 weeks of metformin treatment, whether in the randomized or open-label period, based upon genotypes at polymorphisms in five genes previously associated with metformin response in diabetes: ATM, SLC2A2, MATE1, MATE2, and OCT1. Results: In the primary analysis, both ATM and OCT1 showed significant effects of genotype on change in body mass index z-scores, the primary outcome measure, during the first 16 weeks of treatment with metformin. No other polymorphism showed a significant difference. Conclusion: As has been shown for metformin treatment in diabetes, genetic variation may predict response to metformin for weight gain in youth with ASD treated with mixed receptor antagonists. Further work is needed to replicate these findings and evaluate whether they can be used prospectively to improve outcomes.

Health Benefits of Anti-aging Drugs

Aging, as a physiological process mediated by numerous regulatory pathways and transcription factors, is manifested by continuous progressive functional decline and increasing risk of chronic diseases. There is an increasing interest to identify pharmacological agents for treatment and prevention of age-related disease in humans. Animal models play an important role in identification and testing of anti-aging compounds; this step is crucial before the drug will enter human clinical trial or will be introduced to human medicine. One of the main goals of animal studies is better understanding of mechanistic targets, therapeutic implications and side-effects of the drug, which may be later translated into humans. In this chapter, we summarized the effects of different drugs reported to extend the lifespan in model organisms from round worms to rodents. Resveratrol, rapamycin, metformin and aspirin, showing effectiveness in model organism life- and healthspan extension mainly target the master regulators of aging such as mTOR, FOXO and PGC1α, affecting autophagy, inflammation and oxidative stress. In humans, these drugs were demonstrated to reduce inflammation, prevent CVD, and slow down the functional decline in certain organs. Additionally, potential anti-aging pharmacologic agents inhibit cancerogenesis, interfering with certain aspects of cell metabolism, proliferation, angioneogenesis and apoptosis.

Pharmacotherapy of obesity: Available medications and drugs under investigation

Obesity is a chronic disease with a continuously rising prevalence that currently affects more than half a billion people worldwide. Energy balance and appetite are highly regulated via central and peripheral mechanisms, and weight loss triggers a homeostatic response leading to weight regain. Lifestyle and behavioral modifications are the cornerstones of obesity management; however, they often fail to achieve or sustain long-term weight loss. Pharmacotherapy added onto lifestyle modifications results in an additional, albeit limited, weight reduction. Regardless, this weight reduction of 5-10% conveys multiple cardiovascular and metabolic benefits. In this review, evidence on the food and drug administration (FDA)-approved medications, i.e., orlistat, lorcaserin, phentermine/topiramate, liraglutide and naltrexone/bupropion, is summarized. Furthermore, anti-obesity agents in the pipeline for potential future therapeutic use are presented.

The impact of pharmacological and non-pharmacological interventions to improve physical health outcomes in people with schizophrenia: a meta-review of meta-analyses of randomized controlled trials

We summarized and compared meta-analyses of pharmacological and non-pharmacological interventions targeting physical health outcomes among people with schizophrenia spectrum disorders. Major databases were searched until June 1, 2018. Of 3,709 search engine hits, 27 meta-analyses were included, representing 128 meta-analyzed trials and 47,231 study participants. While meta-analyses were generally of adequate or high quality, meta-analyzed studies were less so. The most effective weight reduction interventions were individual lifestyle counseling (standardized mean difference, SMD=-0.98) and exercise interventions (SMD=-0.96), followed by psychoeducation (SMD=-0.77), aripiprazole augmentation (SMD=-0.73), topiramate (SMD=-0.72), d-fenfluramine (SMD=-0.54) and metformin (SMD=-0.53). Regarding waist circumference reduction, aripiprazole augmentation (SMD=-1.10) and topiramate (SMD=-0.69) demonstrated the best evidence, followed by dietary interventions (SMD=-0.39). Dietary interventions were the only to significantly improve (diastolic) blood pressure (SMD=-0.39). Switching from olanzapine to quetiapine or aripiprazole (SMD=-0.71) and metformin (SMD=-0.65) demonstrated best efficacy for reducing glucose levels, followed by glucagon-like peptide-1 receptor agonists (SMD=-0.39), dietary interventions (SMD=-0.37) and aripiprazole augmentation (SMD=-0.34), whereas insulin resistance improved the most with metformin (SMD=-0.75) and rosiglitazone (SMD=-0.44). Topiramate had the greatest efficacy for triglycerides (SMD=-0.68) and low-density lipoprotein (LDL)-cholesterol (SMD=-0.80), whereas metformin had the greatest beneficial effects on total cholesterol (SMD=-0.51) and high-density lipoprotein (HDL)-cholesterol (SMD=0.45). Lifestyle interventions yielded small effects for triglycerides, total cholesterol and LDL-cholesterol (SMD=-0.35 to -0.37). Only exercise interventions increased exercise capacity (SMD=1.81). Despite frequent physical comorbidities and premature mortality mainly due to these increased physical health risks, the current evidence for pharmacological and non-pharmacological interventions in people with schizophrenia to prevent and treat these conditions is still limited and more larger trials are urgently needed.

Clinical Considerations Regarding the Use of Obesity Pharmacotherapy in Adolescents with Obesity

A growing number of youth suffer from obesity and in particular severe obesity for which intensive lifestyle intervention does not adequately reduce excess adiposity. A treatment gap exists wherein effective treatment options for an adolescent with severe obesity include intensive lifestyle modification or metabolic and bariatric surgery while the application of obesity pharmacotherapy remains largely underutilized. These youth often present with numerous obesity-related comorbid diseases, including hypertension, dyslipidemia, prediabetes/type 2 diabetes, obstructive sleep apnea, nonalcoholic fatty liver disease, musculoskeletal problems, and psychosocial issues such as depression, anxiety, and social stigmatization. Current pediatric obesity treatment algorithms for pediatric primary care providers focus primarily on intensive lifestyle intervention with escalation of treatment intensity through four stages of intervention. Although a recent surge in the number of Food and Drug Administration-approved medications for obesity treatment has emerged in adults, pharmacotherapy options for youth remain limited. Recognizing treatment and knowledge gaps related to pharmacological agents and the urgent need for more effective treatment strategies in this population, discussed here are the efficacy, safety, and clinical application of obesity pharmacotherapy in youth with obesity based on current literature. Legal ramifications, informed consent regulations, and appropriate off-label use of these medications in pediatrics are included, focusing on prescribing practices and prescriber limits.

Combination of Oligofructose and Metformin Alters the Gut Microbiota and Improves Metabolic Profiles, Contributing to the Potentiated Therapeutic Effects on Diet-Induced Obese Animals

Accumulating studies implicate that the metformin (MET)- and oligofructose (OFS)-altered gut microbiota may play roles in the improvement of type 2 diabetes mellitus (T2DM) and obesity. However, whether the combined administration of OFS and MET could effectively affect the gut microbiota and improve metabolic profiles remains unknown. Here, we randomized diet-induced obesity (DIO) rats to OFS, MET, or MET+OFS for 8 weeks and demonstrated that the combined administration of OFS+MET possessed potentiated effects on the glycemia, body weight, and gut microbiome. In addition, fecal samples from the MET and MET+OFS group were exchanged and transferred to germ-free rats induced by antibiotics. Not surprisingly, the glucose tolerance and serum levels of endotoxin, free fatty acids (FFA), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), and interleukin-6 (IL-6) were all sustainably improved among OFS+MET fecal microbiota-treated DIO rats while the MET fecal microbiota-treated ones presented a relatively reverse trend. Furthermore, transfer of fecal samples from the rats after 8 weeks of treatment to antibiotics-treated germ-free mice significantly improved metabolic profiles, including glucose tolerance and weight reduction in mice that received MET+OFS-altered microbiota. In conclusion, the present study illustrated that the effects of OFS and MET combined treatment on gut microbiota, especially for the MET-induced side effect-related ones, and host metabolism were of greater magnitude than individual OFS or MET treatment in obese rats and mice. Therefore, it is likely that combined administration of OFS and MET may offer a novel and promising strategy for reducing side effects induced by MET and improving metabolic outcomes, particularly glycemia control and weight reduction.

Metformin as a geroprotector: experimental and clinical evidence

Apart from being a safe, effective and globally affordable glucose-lowering agent for the treatment of diabetes, metformin has earned much credit in recent years as a potential anti-aging formula. It has been shown to significantly increase lifespan and delay the onset of age-associated decline in several experimental models. The current review summarizes advances in clinical research on the potential role of metformin in the field of geroprotection, highlighting findings from pre-clinical studies on known and putative mechanisms behind its beneficial properties. A growing body of evidence from clinical trials demonstrates that metformin can effectively reduce the risk of many age-related diseases and conditions, including cardiometabolic disorders, neurodegeneration, cancer, chronic inflammation, and frailty. Metformin also holds promise as a drug that could be repurposed for chemoprevention or adjuvant therapy for certain cancer types. Moreover, due to the ability of metformin to induce autophagy by activation of AMPK, it is regarded as a potential hormesis-inducing agent with healthspan-promoting and pro-longevity properties. Long-term intake of metformin is associated with low risk of adverse events; however, well-designed clinical trials are still warranted to enable potential use of this therapeutic agent as a geroprotector.

Power-up: A Reanalysis of 'Power Failure' in Neuroscience Using Mixture Modeling

Recently, evidence for endemically low statistical power has cast neuroscience findings into doubt. If low statistical power plagues neuroscience, then this reduces confidence in the reported effects. However, if statistical power is not uniformly low, then such blanket mistrust might not be warranted. Here, we provide a different perspective on this issue, analyzing data from an influential study reporting a median power of 21% across 49 meta-analyses (Button et al., 2013). We demonstrate, using Gaussian mixture modeling, that the sample of 730 studies included in that analysis comprises several subcomponents so the use of a single summary statistic is insufficient to characterize the nature of the distribution. We find that statistical power is extremely low for studies included in meta-analyses that reported a null result and that it varies substantially across subfields of neuroscience, with particularly low power in candidate gene association studies. Therefore, whereas power in neuroscience remains a critical issue, the notion that studies are systematically underpowered is not the full story: low power is far from a universal problem.SIGNIFICANCE STATEMENT Recently, researchers across the biomedical and psychological sciences have become concerned with the reliability of results. One marker for reliability is statistical power: the probability of finding a statistically significant result given that the effect exists. Previous evidence suggests that statistical power is low across the field of neuroscience. Our results present a more comprehensive picture of statistical power in neuroscience: on average, studies are indeed underpowered-some very seriously so-but many studies show acceptable or even exemplary statistical power. We show that this heterogeneity in statistical power is common across most subfields in neuroscience. This new, more nuanced picture of statistical power in neuroscience could affect not only scientific understanding, but potentially policy and funding decisions for neuroscience research.

Is the perceived placebo effect comparable between adults and children? A meta-regression analysis

BACKGROUND

A potential larger perceived placebo effect in children compared with adults could influence the detection of the treatment effect and the extrapolation of the treatment benefit from adults to children. This study aims to explore this potential difference, using a meta-epidemiological approach.

METHODS

A systematic review of the literature was done to identify trials included in meta-analyses evaluating a drug intervention with separate data for adults and children. The standardized mean change and the proportion of responders (binary outcomes) were used to calculate the perceived placebo effect. A meta-regression analysis was conducted to test for the difference between adults and children of the perceived placebo effect.

RESULTS

For binary outcomes, the perceived placebo effect was significantly more favorable in children compared with adults (β = 0.13; P = 0.001). Parallel group trials (β = -1.83; P < 0.001), subjective outcomes (β = -0.76; P < 0.001), and the disease type significantly influenced the perceived placebo effect.

CONCLUSION

The perceived placebo effect is different between adults and children for binary outcomes. This difference seems to be influenced by the design, the disease, and outcomes. Calibration of new studies for children should consider cautiously the placebo effect in children.

Metformin: an Old Therapy that Deserves a New Indication for the Treatment of Obesity

Metformin is not currently used for weight loss or diabetes prevention because it lacks an FDA indication for obesity and/or pre-diabetes treatment. Based on the evidence, metformin has been shown to decrease the incidence of type 2 diabetes, and compares favorably to other weight-loss medications in terms of efficacy as well as safety. Thus, metformin should be considered for a treatment indication in patients with these conditions.

Metformin for Clozapine Associated Obesity: A Systematic Review and Meta-Analysis

BACKGROUND

Although clozapine is the gold-standard for treatment refractory schizophrenia, it has the worst metabolic profile of all antipsychotics. This is partly mediated by clozapine's impact on glucagon-like peptide (GLP-1). There is an absence of robust evidence for effective treatments for clozapine associated weight gain and metabolic syndrome. Metformin, with its role in increasing GLP-1 may aid weight loss among people on clozapine.

METHODS

We conducted a systematic-review and meta-analysis of metformin versus placebo for change in weight and metabolic syndrome for people on clozapine without diabetes mellitus. We searched the Cochrane Schizophrenia Group's trial register, Pubmed and Embase, as well as the following Chinese databases: the Chinese Biomedical Literature Service System and China Knowledge Resource Integrated Database. This was supplemented by hand searches of key papers.

RESULTS

Eight studies, of which three were from Chinese databases, with 478 participants were included. We found that metformin was superior to placebo in terms of weight loss (-3.12kg, 95%CI -4.88kg to -1.37kg) and BMI (-1.18kg/m2, 95%CI -1.76kg/m2 to -0.61kg/m2). Metformin significantly improved three of the five components of metabolic syndrome; waist circumference, fasting glucose and triglycerides. Sensitivity analysis on study quality and duration did not greatly impact results.

CONCLUSIONS

Metformin led to clinically meaningful weight loss among people on clozapine, and may reduce the rates of metabolic syndrome. Inclusion of metformin into the treatment protocols of people on clozapine, as tolerated, should be considered.

TRIAL REGISTRATION

PROSPERO registration number: CRD42015029723.

A Naturalistic Randomized Placebo-Controlled Trial of Extended-Release Metformin to Prevent Weight Gain Associated With Olanzapine in a US Community-Dwelling Population

OBJECTIVE

This 24-week pilot study assessed the efficacy, tolerability, and safety of adjunctive metformin versus placebo for the prevention of olanzapine-associated weight gain in community-dwelling adult patients with schizophrenia, schizoaffective disorder, bipolar disorder, or major depression with psychotic features.

METHODS

In a double-blind study, 25 patients were randomly assigned to receive 24 weeks of either olanzapine plus metformin or olanzapine plus placebo. Metformin extended release was titrated to 2000 mg daily as tolerated. No other antipsychotics were allowed, whereas psychotropic medications including antidepressants and mood stabilizers were permitted. The primary outcome measures were change in body weight and homeostatic model assessment for insulin resistance from baseline to week 24.

RESULTS

The intent-to-treat population comprised patients who had 1 or more post-baseline visit. Mean change in body weight for the olanzapine plus metformin (O/M) group was 5.5 lb, which was less than the 12.8 lb gain for the olanzapine plus placebo (O/P) group (P < 0.05). Compared with O/P group who gained 7% of their body weight, patients in the O/M group gained 3% (P < 0.037). Body mass index change in the O/M group was 0.85 versus 2.02 in the O/P group (P < 0.045). There was a trend for a greater increase in baseline to end point homeostatic model assessment for insulin resistance and waist circumference in the O/P group versus the O/M group.

CONCLUSIONS

In this naturalistic sample of typical US community-dwelling patients, metformin was effective and well tolerated for the prevention of olanzapine-associated weight gain. Adjunctive metformin should be studied in a similar but larger population to determine its role in the prevention of olanzapine-associated weight gain.

Metformin for Lithium-induced Weight Gain: A Case Report

Lithium is the first line treatment for maintenance treatment of bipolar disorder. Among the long term adverse effects, weight gain is likely to affect a subset of patients. There is no specific guideline for the treatment of lithium-induced weight gain. We report a young male with bipolar disorder who had significant weight gain with lithium (25 kg), which responded to metformin treatment at 500 mg twice daily. The proposed mechanism of weight lowering effect of metformin includes changes in hypothalamic physiology, including leptin and insulin sensitivity, as well as circadian rhythm changes affecting food intake, regulation of fat oxidation and storage in liver, skeletal muscle, and adipose tissue.

Metformin for treatment of antipsychotic-induced weight gain in a South Asian population with schizophrenia or schizoaffective disorder: A double blind, randomized, placebo controlled study

BACKGROUND

Antipsychotic-induced weight gain causes serious health problems. We investigated the efficacy and safety of metformin in treating antipsychotic-induced weight gain in South Asian patients.

METHODS

Sixty six adult patients with schizophrenia or schizoaffective disorder treated, with atypical antipsychotics, and who had increased by more than 10% their pre treatment body weight, were randomly assigned to receive metformin or placebo in a double-blind study. Patients received usual treatment and metformin 500 mg or placebo twice daily for 24 weeks. The primary outcome measure was change in body weight from baseline to week 24. Linear mixed models were used in the analysis.

RESULTS

Mean change in body weight in the metformin group was -1.56 kg (95% CI=-3.06 to -0.05) and 1.0 kg (95% CI=0.03-1.97) in the placebo group. Between-group difference was 2.56 kg. At 24 weeks the between-group difference showed significant time-by-treatment interaction (F=3.23, p=0.004). Between-group difference in BMI showed significant time-by-treatment interaction (F=3.41 p=0.03). There was no significant difference in waist-hip ratio or fasting blood sugar.

CONCLUSIONS

Metformin is effective in reducing weight in South Asian patients with schizophrenia or schizoaffective disorder who had increased their body by more than 10% after treatment with atypical antipsychotics.

Metformin for Weight Gain and Metabolic Abnormalities Associated With Antipsychotic Treatment: Meta-Analysis of Randomized Placebo-Controlled Trials

This meta-analysis examined the effectiveness and safety of metformin to prevent or treat weight gain and metabolic abnormalities associated with antipsychotic drugs. We systematically searched in both English- and Chinese-language databases for metformin randomized controlled clinical trials (RCTs) using placebo in patients taking antipsychotics. Twenty-one RCTs (11 published in English and 10 in Chinese) involving 1547 subjects (778 on metformin, 769 on placebo) were included in this meta-analysis. Metformin was significantly superior to placebo (standard mean differences, -0.69 to -0.51; P = 0.01-0.0001) in the primary outcome measures (body weight, body mass index, fasting glucose, fasting insulin, triglycerides, and total cholesterol). Metformin was significantly superior to placebo in some secondary outcome measures but not in others. Significantly higher frequencies of nausea/vomiting and diarrhea were found in the metformin group, but no differences were found in other adverse drug reactions. In the metformin group, the frequency of nausea/vomiting was 14%, and of diarrhea, 7%. Subgroup and sensitivity analyses demonstrated that primary outcomes were influenced by ethnicity, treatment style (intervention vs prevention), metformin dose, study duration, and mean age. Body weight standard mean difference was -0.91 (confidence interval [CI], -1.40 to -0.41) in 3 prevention RCTs in naive patients, -0.66 (CI, -1.02 to -0.30) in 5 intervention RCTs during the first year, and -0.50 (CI, -0.73 to -0.27) in 9 intervention RCTs in chronic patients. This meta-analysis suggests that adjunctive metformin is an effective, safe, and reasonable choice for antipsychotic-induced weight gain and metabolic abnormalities.

Efficacy and safety of metformin or oral contraceptives, or both in polycystic ovary syndrome

Background

Polycystic ovary syndrome (PCOS) is an endocrinopathy that affects approximately 10% of reproductive-aged women throughout their lives. Women with PCOS present with heterogeneous symptoms including ovulatory dysfunction, hyperandrogenism, and polycystic ovaries. Therefore, lifelong individualized management should be considered. Pharmacological agents commonly used to manage the symptoms are metformin and oral contraceptive pills. Although these medications have been beneficial in treating PCOS symptoms, their efficacy and safety are still not entirely elucidated. This study aimed to report the efficacy and safety of metformin, oral contraceptives, or their combination in the treatment of PCOS and to define their specific individual roles.

Methods

A literature search of original studies published in PubMed and Scopus was conducted to identify studies comparing metformin with oral contraceptives or evaluating the combination of both in PCOS.

Results

Eight clinical trials involving 313 patients were examined in the review. The intervention dosage of metformin ranged from 1,000 to 2,000 mg/d and that of oral contraceptives was ethinylestradiol 35 µg and cyproterone acetate 2 mg. Lower body mass index was observed with regimens including metformin, but increased body mass index was observed in monotherapy with oral contraceptives. Administration of metformin or oral contraceptives, especially as monotherapy, had a negative effect on lipid profiles. In addition, there are still uncertainties surrounding the effects of metformin or oral contraceptives in the management of insulin level, although they improved total testosterone and sex hormone-binding globulin levels. In the included studies, significant side effects due to metformin or oral contraceptives were not reported.

Conclusion

The clinical trials suggest that metformin or oral contraceptives are at least patient convenient, efficacious, and safe for the treatment of PCOS. However, well-designed, prospective, long-term, large-scale, randomized clinical trials are necessary to elucidate the efficacy and safety of metformin, oral contraceptives, or both in the treatment of PCOS, and to elucidate their individual roles in the treatment of this condition.

Evaluation and Treatment of Severe Obesity in Childhood

Pediatric obesity is highly prevalent in developed countries globally (and worsening in developing countries) and threatens to shorten the lifespan of the current generation. At highest risk for weight-related comorbidities including Type 2 diabetes mellitus, non-alcoholic fatty liver disease and dyslipidemia is a sub-set of children with severe obesity, often defined as a body mass index (BMI) percentile ≥99^th percentile for age and sex. The pathophysiology of severe obesity in childhood is complex, resulting from the dynamic interplay of a myriad of individual and societal factors including genetic predisposition and health behaviors contributing to energy imbalance. Approximately 4–6% of children have severe obesity, representing a common scenario encountered by providers, and intervention is critical to halt ongoing weight gain and, when possible, reverse the trend. Clinical approaches promoting behavioral weight loss may result in modest, albeit clinically significant, reductions in BMI; however, such changes are often difficult to maintain long-term. Data regarding the impact of targeted pharmacotherapy including agents such as orlistat are limited in the pediatric population and again only suggest modest results. However, increasing evidence suggest that surgical treatment, as an adjunct to ongoing lifestyle changes, may be a promising option in carefully-screened adolescents with severe obesity and weight-related comorbidities who are motivated to adhere to the long-term treatment needs.

Different treatment benefits were estimated by clinical trials performed in adults compared with those performed in children

OBJECTIVE

Our main objective was to see whether the therapeutic benefit observed in placebo controlled randomized controlled trials (RCTs) is different between adults and children.

STUDY DESIGN AND SETTING

We searched three electronic databases for meta-analyses that included double-blind, placebo-controlled RCTs with separate results for adults and children. The selected reviews were classified according to disease and drug used. The heterogeneity of treatment response between adults and children was measured using ratio of odds ratios (RORs).

RESULTS

We selected 89 meta-analyses and calculated RORs for 124 drugs. Heterogeneity in the direction of the treatment effect was observed in one drug and heterogeneity in the quantity of the treatment effect for 13 drugs, indicating significantly different treatment effect in adults when compared with children. RORs were not significantly different from 1 for 110 drugs. For 36 of these drugs, the treatment effect was confirmed in both populations.

CONCLUSION

We found different treatment benefits estimated by clinical trials performed in adults compared with those performed in children for 14 of 124 drugs. Data on dose adjustment and child age groups from RCTs were not adequately reported to investigate their influence on the treatment benefit dissimilarities.

Therapeutic Use of Metformin in Prediabetes and Diabetes Prevention

People with elevated, non-diabetic, levels of blood glucose are at risk of progressing to clinical type 2 diabetes and are commonly termed 'prediabetic'. The term prediabetes usually refers to high-normal fasting plasma glucose (impaired fasting glucose) and/or plasma glucose 2 h following a 75 g oral glucose tolerance test (impaired glucose tolerance). Current US guidelines consider high-normal HbA1c to also represent a prediabetic state. Individuals with prediabetic levels of dysglycaemia are already at elevated risk of damage to the microvasculature and macrovasculature, resembling the long-term complications of diabetes. Halting or reversing the progressive decline in insulin sensitivity and β-cell function holds the key to achieving prevention of type 2 diabetes in at-risk subjects. Lifestyle interventions aimed at inducing weight loss, pharmacologic treatments (metformin, thiazolidinediones, acarbose, basal insulin and drugs for weight loss) and bariatric surgery have all been shown to reduce the risk of progression to type 2 diabetes in prediabetic subjects. However, lifestyle interventions are difficult for patients to maintain and the weight loss achieved tends to be regained over time. Metformin enhances the action of insulin in liver and skeletal muscle, and its efficacy for delaying or preventing the onset of diabetes has been proven in large, well-designed, randomised trials, such as the Diabetes Prevention Program and other studies. Decades of clinical use have demonstrated that metformin is generally well-tolerated and safe. We have reviewed in detail the evidence base supporting the therapeutic use of metformin for diabetes prevention.

[Prevention and Treatment of Common Acute Adverse Effects With Antipsychotic Use in Adults With Schizophrenia Diagnosis]

OBJECTIVE

To determine the most adequate strategies for the prevention and treatment of the acute adverse effects of the use of antipsychotics.

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. A systematic literature search was carried out. The evidence was presented to the Guideline Developing Group and recommendations, employing the GRADE system, were produced.

RESULTS

The non-pharmacological interventions such as nutritional counseling by a nutritionist, exercise and psychotherapy are effective in preventing weight gain with the use of antipsychotics. (Kg Weight reduction in DM of -3.05 (-4.16, -1.94)). The antipsychotic change from olanzapine to aripiprazole showed weight loss and decreased BMI (decreased weight in KG DM -3.21 (-9.03, -2.61). The use of beta blockers was ineffective in reducing akathisia induced by antipsychotic; using as outcome the 50% reduction of symptoms of akathisia comparing beta-blockers with placebo RR was 1.4 (0.59, 1.83).

CONCLUSION

It is recommended to make psychotherapeutic accompaniment and nutrition management of overweight for patients with weight gain. If these alternatives are ineffective is suggested to change the antipsychotic or consider starting metformin. For the management of drug-induced akathisia it is recommended to decrease the dose of the drug and the addition of lorazepam. It is recommended using 5mg biperiden IM or trihexyphenidyl 5mg orally in case of secondary acute dystonia and for the treatment of antipsychotic-induced parkinsonism to decrease the dose of antipsychotic or consider using 2 - 4mg/day of biperiden or diphenhydramine 50mg once daily.

Clinical review: Drugs commonly associated with weight change: a systematic review and meta-analysis

CONTEXT

Various drugs affect body weight as a side effect.

OBJECTIVE

We conducted this systematic review and meta-analysis to summarize the evidence about commonly prescribed drugs and their association with weight change.

DATA SOURCES

MEDLINE, DARE, and the Cochrane Database of Systematic Reviews were searched to identify published systematic reviews as a source for trials.

STUDY SELECTION

We included randomized trials that compared an a priori selected list of drugs to placebo and measured weight change.

DATA EXTRACTION

We extracted data in duplicate and assessed the methodological quality using the Cochrane risk of bias tool.

RESULTS

We included 257 randomized trials (54 different drugs; 84 696 patients enrolled). Weight gain was associated with the use of amitriptyline (1.8 kg), mirtazapine (1.5 kg), olanzapine (2.4 kg), quetiapine (1.1 kg), risperidone (0.8 kg), gabapentin (2.2 kg), tolbutamide (2.8 kg), pioglitazone (2.6 kg), glimepiride (2.1 kg), gliclazide (1.8 kg), glyburide (2.6 kg), glipizide (2.2 kg), sitagliptin (0.55 kg), and nateglinide (0.3 kg). Weight loss was associated with the use of metformin (1.1 kg), acarbose (0.4 kg), miglitol (0.7 kg), pramlintide (2.3 kg), liraglutide (1.7 kg), exenatide (1.2 kg), zonisamide (7.7 kg), topiramate (3.8 kg), bupropion (1.3 kg), and fluoxetine (1.3 kg). For many other remaining drugs (including antihypertensives and antihistamines), the weight change was either statistically nonsignificant or supported by very low-quality evidence.

CONCLUSIONS

Several drugs are associated with weight change of varying magnitude. Data are provided to guide the choice of drug when several options exist and institute preemptive weight loss strategies when obesogenic drugs are prescribed.

The concomitant use of second-generation antipsychotics and long-term antiretroviral therapy may be associated with increased cardiovascular risk

To study the effect of concurrent use of second-generation antipsychotics (SGAs) on metabolic syndrome (MetS) components conferring increased cardiovascular risk in a sample of human immunodeficiency virus (HIV)-infected adults taking antiretroviral therapy (ART). A retrospective study of participants consecutively recruited at the UCSD HIV Neurobehavioral Research Program examined effects of combined ART and SGAs on body mass index (BMI), nonfasting serum lipids, diabetes mellitus (DM) incidence, and mean arterial pressure (MAP). Metabolic outcome variables and covariates were compared using t-tests, Chi-squared or Fisher's exact tests. Linear and logistic multivariable models explored metabolic outcomes for participants taking (SGA+) or not taking (SGA-) concomitant SGAs, after controlling for demographic and HIV disease- and ART-related covariates. Of 2229 HIV-infected participants, 12% (N=258) were treated with SGAs. In multivariable models adjusted for relevant covariates, the SGA+ group had significantly higher mean triglycerides, significantly higher odds of DM, significantly higher MAPs and marginally higher BMI. The use of SGAs in HIV-infected adults taking ART was independently associated with worse indicators of MetS and cardiovascular risk. Aggressive monitoring for the metabolic complications from concurrent SGA and ART is indicated in all patients receiving these medication combinations.

An evolving scientific basis for the prevention and treatment of pediatric obesity

The 2013 Pennington Biomedical Research Center's Scientific Symposium focused on the treatment and management of pediatric obesity and was designed to (i) review recent scientific advances in the prevention, clinical treatment and management of pediatric obesity, (ii) integrate the latest published and unpublished findings and (iii) explore how these advances can be integrated into clinical and public health approaches. The symposium provided an overview of important new advances in the field, which led to several recommendations for incorporating the scientific evidence into practice. The science presented covered a range of topics related to pediatric obesity, including the role of genetic differences, epigenetic events influenced by in utero development, pre-pregnancy maternal obesity status, maternal nutrition and maternal weight gain on developmental programming of adiposity in offspring. Finally, the relative merits of a range of various behavioral approaches targeted at pediatric obesity were covered, together with the specific roles of pharmacotherapy and bariatric surgery in pediatric populations. In summary, pediatric obesity is a very challenging problem that is unprecedented in evolutionary terms; one which has the capacity to negate many of the health benefits that have contributed to the increased longevity observed in the developed world.

Metformin for weight loss and metabolic control in overweight outpatients with schizophrenia and schizoaffective disorder

OBJECTIVE

The purpose of this study was to determine whether metformin promotes weight loss in overweight outpatients with chronic schizophrenia or schizoaffective disorder.

METHOD

In a double-blind study, 148 clinically stable, overweight (body mass index [BMI] ≥27) outpatients with chronic schizophrenia or schizoaffective disorder were randomly assigned to receive 16 weeks of metformin or placebo. Metformin was titrated up to 1,000 mg twice daily, as tolerated. All patients continued to receive their prestudy medications, and all received weekly diet and exercise counseling. The primary outcome measure was change in body weight from baseline to week 16.

RESULTS

Fifty-eight (77.3%) patients who received metformin and 58 (81.7%) who received placebo completed 16 weeks of treatment. Mean change in body weight was -3.0 kg (95% CI=-4.0 to -2.0) for the metformin group and -1.0 kg (95% CI=-2.0 to 0.0) for the placebo group, with a between-group difference of -2.0 kg (95% CI=-3.4 to -0.6). Metformin also demonstrated a significant between-group advantage for BMI (-0.7; 95% CI=-1.1 to -0.2), triglyceride level (-20.2 mg/dL; 95% CI=-39.2 to -1.3), and hemoglobin A1c level (-0.07%; 95% CI=-0.14 to -0.004). Metformin-associated side effects were mostly gastrointestinal and generally transient, and they rarely led to treatment discontinuation.

CONCLUSIONS

Metformin was modestly effective in reducing weight and other risk factors for cardiovascular disease in clinically stable, overweight outpatients with chronic schizophrenia or schizoaffective disorder over 16 weeks. A significant time-by-treatment interaction suggests that benefits of metformin may continue to accrue with longer treatment. Metformin may have an important role in diminishing the adverse consequences of obesity and metabolic impairments in patients with schizophrenia.

Improving metabolic parameters of antipsychotic child treatment (IMPACT) study: rationale, design, and methods

BACKGROUND

Youth with serious mental illness may experience improved psychiatric stability with second generation antipsychotic (SGA) medication treatment, but unfortunately may also experience unhealthy weight gain adverse events. Research on weight loss strategies for youth who require ongoing antipsychotic treatment is quite limited. The purpose of this paper is to present the design, methods, and rationale of the Improving Metabolic Parameters in Antipsychotic Child Treatment (IMPACT) study, a federally funded, randomized trial comparing two pharmacologic strategies against a control condition to manage SGA-related weight gain.

METHODS

The design and methodology considerations of the IMPACT trial are described and embedded in a description of health risks associated with antipsychotic-related weight gain and the limitations of currently available research.

RESULTS

The IMPACT study is a 4-site, six month, randomized, open-label, clinical trial of overweight/obese youth ages 8-19 years with pediatric schizophrenia-spectrum and bipolar-spectrum disorders, psychotic or non-psychotic major depressive disorder, or irritability associated with autistic disorder. Youth who have experienced clinically significant weight gain during antipsychotic treatment in the past 3 years are randomized to either (1) switch antipsychotic plus healthy lifestyle education (HLE); (2) add metformin plus HLE; or (3) HLE with no medication change. The primary aim is to compare weight change (body mass index z-scores) for each pharmacologic intervention with the control condition. Key secondary assessments include percentage body fat, insulin resistance, lipid profile, psychiatric symptom stability (monitored independently by the pharmacotherapist and a blinded evaluator), and all-cause and specific cause discontinuation. This study is ongoing, and the targeted sample size is 132 youth.

CONCLUSION

Antipsychotic-related weight gain is an important public health issue for youth requiring ongoing antipsychotic treatment to maintain psychiatric stability. The IMPACT study provides a model for pediatric research on adverse event management using state-of-the art methods. The results of this study will provide needed data on risks and benefits of two pharmacologic interventions that are already being used in pediatric clinical settings but that have not yet been compared directly in randomized trials.

TRIAL REGISTRATION

Clinical Trials.gov NCT00806234.

Weight gain and increase of body mass index among children and adolescents treated with antipsychotics: a critical review

We performed an updated review of the available literature on weight gain and increase of body mass index (BMI) among children and adolescents treated with antipsychotic medications. A PubMed search was conducted specifying the following MeSH terms: (antipsychotic agents) hedged with (weight gain) or (body mass index). We selected 127 reports, including 71 intervention trials, 42 observational studies and 14 literature reviews. Second-generation antipsychotics (SGAs), in comparison with first-generation antipsychotics, are associated with a greater risk for antipsychotic-induced weight gain although this oversimplification should be clarified by distinguishing across different antipsychotic drugs. Among SGAs, olanzapine appears to cause the most significant weight gain, while ziprasidone seems to cause the least. Antipsychotic-induced BMI increase appears to remain regardless of the specific psychotropic co-treatment. Children and adolescents seem to be at a greater risk than adults for antipsychotic-induced weight gain; and the younger the child, the higher the risk. Genetic or environmental factors related to antipsychotic-induced weight gain among children and adolescents are mostly unknown, although certain genetic factors related to serotonin receptors or hormones such as leptin, adiponectin or melanocortin may be involved. Strategies to reduce this antipsychotic side effect include switching to another antipsychotic drug, lowering the dosage or initiating treatment with metformin or topiramate, as well as non-pharmacological interventions. Future research should avoid some methodological limitations such as not accounting for age- and sex-adjusted BMI (zBMI), small sample size, short period of treatment, great heterogeneity of diagnoses and confounding by indication.

Power failure: why small sample size undermines the reliability of neuroscience

A study with low statistical power has a reduced chance of detecting a true effect, but it is less well appreciated that low power also reduces the likelihood that a statistically significant result reflects a true effect. Here, we show that the average statistical power of studies in the neurosciences is very low. The consequences of this include overestimates of effect size and low reproducibility of results. There are also ethical dimensions to this problem, as unreliable research is inefficient and wasteful. Improving reproducibility in neuroscience is a key priority and requires attention to well-established but often ignored methodological principles.

Pharmacotherapy for childhood obesity: present and future prospects

Pediatric obesity is a serious medical condition associated with significant comorbidities during childhood and adulthood. Lifestyle modifications are essential for treating children with obesity, yet many have insufficient response to improve health with behavioral approaches alone. This review summarizes the relatively sparse data on pharmacotherapy for pediatric obesity and presents information on obesity medications in development. Most previously studied medications demonstrated, at best, modest effects on body weight and obesity-related conditions. It is to be hoped that the future will bring new drugs targeting specific obesity phenotypes that will allow clinicians to use etiology-specific, and therefore more effective, anti-obesity therapies.

Drugs commonly associated with weight change: umbrella systematic review and meta-analysis (Protocol)

BACKGROUND

Many drugs and treatments given to patients for various reasons affect their weight. This side effect is of great importance to patients and is also a concern for the treating physician because weight change may lead to the emergence or worsening of other health conditions.

OBJECTIVE

The aim of this study is to summarize the evidence about commonly prescribed drugs and their association with weight change.

METHODS/DESIGN

Umbrella systematic review and meta-analysis of randomized controlled trials.We will use an umbrella approach to identify eligible randomized controlled trials (RCTs). We will search for systematic reviews of RCTs that compare any of the drugs that have been associated with weight gain (obesogenic) or weight loss (leptogenic); these have been summarized by our experts' panel in a predefined list. Two reviewers will independently determine RCT eligibility. Disagreement will be solved by consensus and arbitrated by a third reviewer. We will extract descriptive, methodological, and efficacy data in duplicate. Our primary continuous outcomes will be weight loss or gain expressed as a mean difference (MD) for weight (kg) or BMI (kg/m2). We will calculate the MD considering the mean difference in weight or BMI between baseline and the last available follow-up in both study arms (drugs and placebo). Our primary dichotomous outcome, presented as a relative risk, will compare the ratio of the incidence of weight change in each trial arm. When possible, results will be pooled using classic random-effects meta-analyses and a summary estimate with 95% confidence interval will provided. We will use the I2 statistic and Cochran's Q test to assess heterogeneity. The risk of bias will be assessed using the Cochrane risk of bias tool. Publication bias, if appropriate, will be evaluated, as well as overall strength of the evidence.

DISCUSSION

This systematic review will offer the opportunity to generate a ranking of commonly prescribed drugs in terms of their effect on weight, allowing guideline developers and patient-physician dyad to choose between available therapies.

Comparative effectiveness of switching antipsychotic drug treatment to aripiprazole or ziprasidone for improving metabolic profile and atherogenic dyslipidemia: a 12-month, prospective, open-label study

We studied the effects of switching antipsychotic drug-treated patients with schizophrenia or bipolar disorder who evidenced adverse metabolic side effects as indicated by a triglyceride/high-density lipoprotein ratio (TG/HDL) ≥ 3.5 to aripiprazole (ARIP; 5-30 mg/day, n = 24) or ziprasidone (ZIP; 40-160 mg/day, n = 28). Anthropometric and metabolic measures, psychopathology, quality of life and motor adverse effects were assessed over a 52-week period with evaluations at baseline, 6, 12, 26 and 52 weeks. There were statistically significant improvements in body weight, body mass index (BMI), TG, HDL and TG/HDL which did not differ between treatments. However, numerous secondary measures including weight and BMI, and the proportion of patients who lost ≥ 7% or who no longer met criteria for obesity, favored ZIP over ARIP. Decreases in total cholesterol and increases in HDL-cholesterol also favored ZIP. On the other hand, decreases in TG/HDL ratio and reduction in HgbA1c favored ARIP. There were no significant time or group × time interaction effects for most psychopathology measures; however, Global Assessment of Functioning Scores favored ARIP at 6 and 12 months. We conclude that switching patients with evidence of metabolic side effects to either ARIP or ZIP may be beneficial for some, but not all metabolic measures, with minimal risk of worsening of psychopathology and possibly some benefit in that regard as well.

The heart of the matter: cardiometabolic care in youth with psychosis

AIM

Weight gain, obesity and metabolic disturbances in youth with psychosis are significant contributors to the health burden of people with psychosis, with a two- to threefold increase in rates compared with the general population and a 20% reduction in life expectancy. Several studies have now described cardiometabolic benefits of a range of interventions, including a structured diet and exercise programmes and metformin for patients receiving antipsychotic medications. Despite the development of Australian consensus guidelines and screening algorithms to detect such metabolic abnormalities, there is a lack of guidelines for clinicians to determine appropriate, timely, targeted prevention and intervention to manage these complications in the youth population.

METHODS

The Bondi Early Psychosis Programme targets young people (aged 15-25 years) experiencing their first episode of psychosis. This service has developed a model of metabolic screening and a treatment algorithm to provide clinicians with recommendations for targeted interventions.

RESULTS

Positive Cardiometabolic Health: an early intervention framework for patients on psychotropic medication describes a method for early detection, prevention and intervention strategies targeting antipsychotic-induced metabolic abnormalities and cardiovascular risk factors.

CONCLUSION

Although further research is required, there is sufficient evidence to support early intervention and prevention strategies to improve physical health outcomes in young people with first-episode psychosis.

Metformin for olanzapine-induced weight gain: a systematic review and meta-analysis

Olanzapine is an atypical antipsychotic that is useful in schizophrenia and bipolar affective disorder, but its use is associated with troublesome weight gain and metabolic syndrome. A variety of pharmacological agents has been studied in the efforts to reverse weight gain induced by olanzapine, but current evidence is insufficient to support any particular pharmacological approach. We conducted a systematic review and meta-analysis of randomized controlled trials of metformin for the treatment of olanzapine-induced weight gain. Systematic review of the literature revealed 12 studies that had assessed metformin for antipsychotic-induced weight gain. Of these, four studies (n= 105) met the review inclusion criteria and were included in the final analysis. Meta-analysis was performed to see the effect size of the treatment on body weight, waist circumference and body-mass index (BMI). Weighted mean difference (WMD) for body weight was 5.02 (95% CI 3.93, 6.10) kg lower with metformin as compared with placebo at 12 weeks. For waist circumference, the test for heterogeneity was significant (P= 0.00002, I(2) = 85.1%). Therefore, a random effects model was used to calculate WMD, which was 1.42 (95% CI 0.29, 3.13) cm lower with metformin as compared with placebo at 12 weeks. For BMI, WMD was 1.82 (95% CI 1.44, 2.19) kg m(-2) lower with metformin as compared with placebo at 12 weeks. Existing data suggest that short term modest weight loss is possible with metformin in patients with olanzapine-induced weight gain.