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Alimentary Pharmacology & Therapeutics Jan 2014Non-alcoholic fatty liver disease (NAFLD) is an umbrella term, which encompasses simple steatosis and non-alcoholic steatohepatitis (NASH). The entire spectrum of NAFLD... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Non-alcoholic fatty liver disease (NAFLD) is an umbrella term, which encompasses simple steatosis and non-alcoholic steatohepatitis (NASH). The entire spectrum of NAFLD has been associated with metabolic syndrome. NASH is associated with increased mortality compared with that of the general population. Many therapeutic options for NASH have been studied. However, there is very little evidence supporting the efficacy of most regimens for the treatment of NASH.
AIM
To provide a review focusing on the current therapeutic options available for patients with NASH as well as to briefly introduce possible future interventions.
METHODS
A MEDLINE, Pubmed and Cochrane Review database search using a combination of keywords, which included non-alcoholic fatty liver disease, non-alcoholic hepatic steatosis, NAFLD, NASH, treatment, therapeutics, vitamin E, orlistat and bariatric surgery. An overall summary of the articles was developed for each section of discussion in this review.
RESULTS
NASH associated with metabolic syndrome can progress advanced fibrosis and cirrhosis. Weight loss and lifestyle modification have been shown to improve NASH. Other medications used for weight loss and metabolic syndrome have been evaluated, such as orlistat, metformin and thiazolidinediones. Alternative regimens using ursodeoxycholic acid, statins and probiotics as well as bariatric surgery have been evaluated, but have not been recommended as first-line treatment for NASH. Vitamin E for NASH patients without diabetes seems to be promising. The lack of effective treatment for NASH suggests the heterogeneity of patients presenting with the NASH phenotype. The best treatment strategy for these patients may be to identify their pathogenic target and develop personalised treatment protocols.
CONCLUSIONS
Currently, there are few options available for the management of NASH. Future targeted treatment strategies based on the pathogenic pathways may be needed to develop effective treatment for patients with NASH.
Topics: Bariatric Surgery; Fatty Liver; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lactones; Metabolic Syndrome; Metformin; Non-alcoholic Fatty Liver Disease; Orlistat; Precision Medicine; Thiazolidinediones; Ursodeoxycholic Acid; Vitamin E; Weight Loss
PubMed: 24206433
DOI: 10.1111/apt.12543 -
PloS One 2012Anti-obesity drugs are widely used to prevent the complications of obesity, however, the effects of anti-obesity drugs on cardiovascular risk factors are unclear at the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Anti-obesity drugs are widely used to prevent the complications of obesity, however, the effects of anti-obesity drugs on cardiovascular risk factors are unclear at the present time. We carried out a comprehensively systematic review and meta-analysis to assess the effects of anti-obesity drugs on cardiovascular risk factors.
METHODOLOGY AND PRINCIPAL FINDINGS
We systematically searched Medline, EmBase, the Cochrane Central Register of Controlled Trials, reference lists of articles and proceedings of major meetings for relevant literatures. We included randomized placebo-controlled trials that reported the effects of anti-obesity drugs on cardiovascular risk factors compared to placebo. Overall, orlistat produced a reduction of 2.39 kg (95%CI-3.34 to -1.45) for weight, a reduction of 0.27 mmol/L (95%CI: -0.36 to -0.17) for total cholesterol, a reduction of 0.21 mmol/L (95%CI: -0.30 to -0.12) for LDL, a reduction of 0.12 mmol/L (95%CI: -0.20 to -0.04) for fasting glucose, 1.85 mmHg reduction (95%CI: -3.30 to -0.40) for SBP, and a reduction of 1.49 mmHg (95%CI: -2.39 to -0.58) for DBP. Sibutramine only showed effects on weight loss and triglycerides reduction with statistical significances. Rimonabant was associated with statistically significant effects on weight loss, SBP reduction and DBP reduction. No other significantly different effects were identified between anti-obesity therapy and placebo.
CONCLUSION/SIGNIFICANCE
We identified that anti-obesity therapy was associated with a decrease of weight regardless of the type of the drug. Orlistat and rimonabant could lead to an improvement on cardiovascular risk factors. However, Sibutramine may have a direct effect on cardiovascular risk factors.
Topics: Anti-Obesity Agents; Cardiovascular Diseases; Humans; Obesity; Randomized Controlled Trials as Topic; Weight Loss
PubMed: 22745703
DOI: 10.1371/journal.pone.0039062 -
Health Technology Assessment... 2012Obesity [defined as a body mass index (BMI) ≥ 30 kg/m(2)] represents a considerable public health problem and is associated with a significant range of comorbidities... (Review)
Review
BACKGROUND
Obesity [defined as a body mass index (BMI) ≥ 30 kg/m(2)] represents a considerable public health problem and is associated with a significant range of comorbidities and an increased mortality risk. The primary aim of the management of obesity is to achieve weight reduction in the interests of health. For obese patients who cannot achieve or maintain a healthy weight by non-pharmacological means, drug therapy is recommended in combination with non-pharmacological interventions such as dietary modifications and exercise.
OBJECTIVE
To evaluate the clinical effectiveness and cost-effectiveness of three pharmacological interventions in obese patients.
DATA SOURCES
Clinical effectiveness data used in the meta-analysis were sourced from articles identified in a systematic review of the literature. Data used to inform transitions to obesity-related comorbidities were derived from the General Practice Research Database (GPRD). The results of the meta-analysis and GPRD analyses informed the economic model supplemented by data from the Health Survey for England and other UK-specific data sourced from the literature.
REVIEW METHODS
A systematic literature review was conducted of the clinical effectiveness and cost-effectiveness of orlistat, sibutramine and rimonabant within their licensed indications for the treatment of obese patients. Electronic bibliographic databases including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched in January 2009, and the reference lists of relevant articles were checked. Studies were included if they compared orlistat, sibutramine or rimonabant with lifestyle and/or exercise advice (standard care), placebo or metformin.
RESULTS
Overall, 94 studies involving 24,808 individuals were included in the clinical meta-analysis. Eighty-three trials included data on weight change, 41 included data on BMI change and 45 and 36 studies reported on 5% and 10% body weight loss, respectively. Overall, the results show that the active drug interventions are all effective at reducing weight and BMI compared with placebo. In the case of sibutramine, the higher dose (15 mg) resulted in a greater reduction than the lower dose (10 mg). Generally, the data quality of the trials included was low with poor reporting of standard errors and standard deviations. Results from the BMI risk models derived from the GPRD showed consistent increases in risk with increasing BMI. Adjustments for key confounders, such as age, sex and smoking status, were found to be statistically significant at the 5% level, in all risk models. Applying linear models to estimate BMI trajectories, for the diabetic cohort, an average increase in BMI of 0.040 per year for both men and women was observed. The non-diabetic cohort model showed an increase in BMI of 0.175 per year for women and 0.145 per year for men. The results of the cost-effectiveness analyses suggest that sibutramine 15 mg dominates the other three active interventions and the net benefit analyses show that sibutramine 15 mg is the most cost-effective alternative for thresholds > £2000 per quality-adjusted life-year (QALY). However, both sibutramine and rimonabant have been withdrawn because of safety concerns relating to potential treatment-induced fatal adverse events. If the proportion of patients who experienced a fatal adverse event was > 1.8% (1.5%, 1.0%) for sibutramine 15 mg (sibutramine 10 mg, rimonabant) the treatment would not be considered cost-effective when using a threshold of £20,000 per QALY.
LIMITATIONS
The clinical review did not include all possible lifestyle comparators, with the inclusion limited to only those trials included one of the active drug interventions. We also excluded all studies not reported in English. Although the clinical review included data from 94 studies, the quality of data was generally low, particularly in terms of the reporting of standard deviation. There was also inconsistency between the results of the mixed-treatment comparison (MTC) and the pair-wise analyses.
CONCLUSION
The MTC of anti-obesity treatments shows that all the active treatments are effective at reducing weight and BMI. The economic results show that, compared with placebo, the treatments are all cost-effective when using a threshold of £20,000 per QALY, and, within the limitations of the data available, sibutramine 15 mg dominates the other three interventions. This work has highlighted many areas of methodological research that could be explored, including assessing inconsistencies within a network to determine differences between the results of pair-wise and MTC analyses; the use of meta-regression methods to look for effect modifiers; exploring the effect of local publication bias; and the use of joint models to analyse the repeated measures of BMI and the time-to-event processes simultaneously.
FUNDING
The National Institute for Health Research Health Technology Assessment programme.
Topics: Anti-Obesity Agents; Cost-Benefit Analysis; Cyclobutanes; Drug Costs; Exercise; Female; Humans; Lactones; Male; Middle Aged; Obesity; Orlistat; Piperidines; Primary Health Care; Pyrazoles; Rimonabant; Risk Reduction Behavior; Treatment Outcome
PubMed: 22340890
DOI: 10.3310/hta16050 -
Open Medicine : a Peer-reviewed,... 2011Although there is general agreement that metformin should be used as first-line pharmacotherapy in patients with type 2 diabetes, uncertainty remains regarding the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Although there is general agreement that metformin should be used as first-line pharmacotherapy in patients with type 2 diabetes, uncertainty remains regarding the choice of second-line therapy once metformin is no longer effective. We conducted a systematic review and meta-analysis to assess the comparative safety and efficacy of all available classes of antihyperglycemic therapies in patients with type 2 diabetes inadequately controlled on metformin monotherapy.
METHODS
MEDLINE, EMBASE, BIOSIS Previews, PubMed and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials published in English from 1980 to October 2009. Additional citations were obtained from grey literature and conference proceedings and through stakeholder feedback. Two reviewers independently selected studies, extracted data and assessed risk of bias. Key outcomes of interest were hemoglobin A1c, body weight, hypoglycemia, quality of life, long-term diabetes-related complications, serious adverse drug events and mortality. Mixed-treatment comparison and pairwise meta-analyses were conducted to pool trial results, when appropriate.
RESULTS
We identified 49 active and non-active controlled randomized trials that compared 2 or more of the following classes of antihyperglycemic agents and weight-loss agents: sulfonylureas, meglitinides, thiazolidinediones (TZDs), dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) analogues, insulins, alpha-glucosidase inhibitors, sibutramine and orlistat. All classes of second-line antihyperglycemic therapies achieved clinically meaningful reductions in hemoglobin A1c (0.6% to 1.0%). No significant differences were found between classes. Insulins and insulin secretagogues were associated with significantly more events of overall hypoglycemia than the other agents, but severe hypoglycemia was rarely observed. An increase in body weight was observed with the majority of second-line therapies (1.8 to 3.0 kg), the exceptions being DPP-4 inhibitors, alpha-glucosidase inhibitors and GLP-1 analogues (0.6 to -1.8 kg). There were insufficient data available for diabetes complications, mortality or quality of life.
INTERPRETATION
DPP-4 inhibitors and GLP-1 analogues achieved improvements in glycemic control similar to those of other second-line therapies, although they may have modest benefits in terms of weight gain and overall hypoglycemia. Further long-term trials of adequate power are required to determine whether newer drug classes differ from older agents in terms of clinically meaningful outcomes.
Topics: Bayes Theorem; Body Weight; Confidence Intervals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Progression; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Metformin; Risk Factors; Time Factors; Treatment Failure
PubMed: 22046219
DOI: No ID Found -
Annals of Internal Medicine Oct 2011Overweight and obesity in adults are common and adversely affect health. (Review)
Review
BACKGROUND
Overweight and obesity in adults are common and adversely affect health.
PURPOSE
To summarize effectiveness and harms of primary care-relevant weight-loss interventions for overweight and obese adults.
DATA SOURCES
MEDLINE, Cochrane Central Register of Controlled Trials, and PsycINFO from January 2005 to September 2010; systematic reviews for identifying trials before 2005.
STUDY SELECTION
Two investigators appraised 6498 abstracts and 648 articles. Clinical trials were included if control groups received minimal interventions. Articles were rated as good, fair, or poor by using design-specific criteria.
DATA EXTRACTION
One investigator abstracted study characteristics and findings for good- and fair-quality studies; a second checked them.
DATA SYNTHESIS
Behaviorally based treatment resulted in 3-kg (6.6-lb) greater weight loss in intervention than control participants after 12 to 18 months, with more treatment sessions associated with greater loss. Limited data suggest weight-loss maintenance for 1 year or more. Orlistat plus behavioral intervention resulted in 3-kg (6.6-lb) more weight loss than did placebo after 12 months. Metformin resulted in less weight loss. Data on effects of weight-loss treatment on long-term health outcomes (for example, death and cardiovascular disease) were insufficient. Weight-loss treatment reduced diabetes incidence in participants with prediabetes. Effects on intermediate outcomes (for example, lipids and blood pressure) were mixed and small. Data on serious medication harms were insufficient. Medications commonly caused withdrawals due to gastrointestinal symptoms.
LIMITATIONS
Few studies reported health outcomes. Behaviorally based treatments were heterogeneous and specific elements were not well-described. Many studies could not be pooled because of insufficient reporting of variance data. Medication trials had high attrition, lacked postdiscontinuation data, and were inadequately powered for rare adverse effects.
CONCLUSION
Behaviorally based treatments are safe and effective for weight loss and maintenance.
PRIMARY FUNDING SOURCE
Agency for Healthcare Research and Quality.
Topics: Anti-Obesity Agents; Behavior Therapy; Combined Modality Therapy; Diet, Reducing; Evidence-Based Medicine; Humans; Lactones; Obesity; Orlistat; Overweight; Patient Dropouts; Primary Health Care; Treatment Outcome
PubMed: 21969342
DOI: 10.7326/0003-4819-155-7-201110040-00006 -
BMJ Clinical Evidence Mar 2011About one third of the US population and one quarter of the UK population are obese, with increased risks of hypertension, dyslipidaemia, diabetes, cardiovascular... (Review)
Review
INTRODUCTION
About one third of the US population and one quarter of the UK population are obese, with increased risks of hypertension, dyslipidaemia, diabetes, cardiovascular disease, osteoarthritis, and some cancers. Fewer than 10% of overweight or obese adults aged 40 to 49 years revert to a normal body weight after 4 years. Nearly 5 million US adults used prescription weight-loss medication between 1996 and 1998, but one quarter of all users were not overweight.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments in adults with obesity? What are the effects of bariatric surgery in adults with morbid obesity? We searched: Medline, Embase, The Cochrane Library, and other important databases up to September 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 39 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review, we present information relating to the effectiveness and safety of the following interventions: bariatric surgery versus medical interventions, biliopancreatic diversion, diethylpropion, gastric bypass, gastric banding, mazindol, orlistat (alone and in combination with sibutramine), phentermine, sibutramine (alone and in combination with orlistat), sleeve gastrectomy, and vertical banded gastroplasty.
Topics: Adult; Diethylpropion; Gastric Bypass; Gastroplasty; Humans; Obesity; Obesity, Morbid; Phentermine; Weight Loss
PubMed: 21411021
DOI: No ID Found -
Neuropsychopharmacology : Official... Jun 2010Antipsychotic-related weight gain and metabolic effects are a critical outcome for patients requiring these medications. A literature search using MEDLINE, Web of... (Meta-Analysis)
Meta-Analysis Review
Antipsychotic-related weight gain and metabolic effects are a critical outcome for patients requiring these medications. A literature search using MEDLINE, Web of Science, PsycNET, and EMBASE for randomized, open and double-blind, placebo-controlled trials of medications targeting antipsychotic-induced weight gain was performed. Primary outcome measures were change and endpoint values in body weight and body mass index (BMI). Secondary outcomes included >or=7% weight gain, all-cause discontinuation, change in waist circumference, glucose and lipid metabolism parameters, and psychiatric symptoms. Sensitivity analyses were conducted to explain heterogeneity of the results. Across 32 studies including 1482 subjects, 15 different medications were tested: amantadine, dextroamphetamine, d-fenfluramine, famotidine, fluoxetine, fluvoxamine, metformin, nizatidine, orlistat, phenylpropanolamine, reboxetine, rosiglitazone, sibutramine, topiramate, and metformin+sibutramine. Compared with placebo, metformin had the greatest weight loss (N=7, n=334, -2.94 kg (confidence interval (CI:-4.89,-0.99)), followed by d-fenfluramine (N=1, n=16, -2.60 kg (CI:-5.14,-0.06)), sibutramine (N=2, n=55, -2.56 kg (CI:-3.91,-1.22)), topiramate (N=2, n=133, -2.52 kg (CI:-4.87,-0.16)), and reboxetine (N=2, n=79, -1.90 kg (CI:-3.07,-0.72)). Weight loss remained significant with metformin initiation after weight gain had occurred, but not when started concomitantly with antipsychotics. Nausea rates were not higher with any treatment compared with placebo. In all, 5 of 15 psychopharmacologic interventions aimed at ameliorating antipsychotic-induced weight gain outperformed placebo. Results were most robust for metformin, although these were modest and heterogeneous. Only one (negative) combination treatment study was available and head-to-head studies are absent. None of the agents were able to entirely reverse weight gain because of antipsychotics. At present, no treatment has sufficient evidence to recommend broad clinical usage. Antipsychotics with no or minimal cardiometabolic liability, as well as interventions that prevent or normalize adverse antipsychotic cardiometabolic effects are needed.
Topics: Animals; Antidepressive Agents; Databases, Factual; Humans; Hypoglycemic Agents; Metabolic Diseases; Randomized Controlled Trials as Topic; Weight Gain
PubMed: 20336059
DOI: 10.1038/npp.2010.21 -
Obesity Reviews : An Official Journal... May 2009Clinical trials of obesity treatments have been limited by substantial dropout. Participant-level variables do not reliably predict attrition, and study-level variables... (Review)
Review
Clinical trials of obesity treatments have been limited by substantial dropout. Participant-level variables do not reliably predict attrition, and study-level variables have not yet been examined. We searched MEDLINE and identified 24 large randomized controlled trials of weight loss medications. These trials were comprised of 23 placebo and 32 drug groups. Two authors independently extracted the following for each treatment group: (i) treatment received; (ii) design characteristics (inclusion of a lead-in period, selection of participants with weight-related comorbidities, study location and number of study visits); (iii) sample characteristics (sample size, % female, and mean baseline age and body mass index); and (iv) attrition (total, adverse event [AE]-related and non-AE-related) at 1 year. The primary outcome was total attrition, which was significantly related to treatment (i.e. 34.9%, 28.6%, 28.3% and 35.1% in placebo, orlistat, sibutramine and rimonabant groups, respectively, P < 0.0001). In adjusted multivariable models, total attrition was significantly lower in groups that completed a pre-randomization lead-in period than in those that did not (29.1% vs. 39.9%, P < 0.01). Gender also was significantly related to total attrition; groups with more women had higher dropout (P < 0.01). The pattern was similar for predicting non-AE-related attrition. Findings suggest ways to design studies that maximize retention.
Topics: Anti-Obesity Agents; Humans; Multivariate Analysis; Patient Dropouts; Randomized Controlled Trials as Topic; Research Design
PubMed: 19389060
DOI: 10.1111/j.1467-789X.2009.00567.x -
BMJ (Clinical Research Ed.) Feb 2007To quantify the effectiveness of pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To quantify the effectiveness of pharmacological and lifestyle interventions to prevent or delay type 2 diabetes in people with impaired glucose tolerance.
DATA SOURCES
Medline, Embase, and the Cochrane library searched up to July 2006. Expert opinions sought and reference lists of identified studies and any relevant published reviews checked.
STUDY SELECTION
Randomised controlled trials that evaluated interventions to delay or prevent type 2 diabetes in individuals with impaired glucose tolerance.
RESULTS
21 trials met the inclusion criteria, of which 17, with 8084 participants with impaired glucose tolerance, reported results in enough detail for inclusion in the meta-analyses. From the meta-analyses the pooled hazard ratios were 0.51 (95% confidence interval 0.44 to 0.60) for lifestyle interventions v standard advice, 0.70 (0.62 to 0.79) for oral diabetes drugs v control, 0.44 (0.28 to 0.69) for orlistat v control, and 0.32 (0.03 to 3.07) for the herbal remedy jiangtang bushen recipe v standard diabetes advice. These correspond to numbers needed to treat for benefit (NNTB) and harm (NNTH) of 6.4 for lifestyle (95% credible interval, NNTB 5.0 to NNTB 8.4), 10.8 for oral diabetes drugs (NNTB 8.1 to NNTB 15.0), 5.4 for orlistat (NNTB 4.1 to NNTB 7.6), and 4.0 for jiangtang bushen (NNTH 16.9 to NNTB 24.8).
CONCLUSIONS
Lifestyle and pharmacological interventions reduce the rate of progression to type 2 diabetes in people with impaired glucose tolerance. Lifestyle interventions seem to be at least as effective as drug treatment.
Topics: Diabetes Mellitus, Type 2; Glucose Intolerance; Humans; Hypoglycemic Agents; Life Style; Publication Bias; Randomized Controlled Trials as Topic; Treatment Outcome
PubMed: 17237299
DOI: 10.1136/bmj.39063.689375.55