Effect of sibutramine on weight management and metabolic control in type 2 diabetes: a meta-analysis of clinical studies

Pharmacotherapy of obesity: An update

Several pharmacological approaches to controlling body weight have been developed over the last decades, albeit with limited success. Currently available agents include centrally acting appetite suppressants and peripherally acting compounds. Efficacy and safety of these agents in the clinical setting require a difficult balance. Further strategies including multiagonists able to simultaneously target multiple actors involved in obesity initiation and expansion such as the glucagon receptor family are under investigation. The results of recent clinical trials are encouraging and highlight emerging compounds as potential game changers. In view of the rising prevalence of obesity and the associated burden of comorbidities worldwide, and compared with other areas of pharmacological intervention, we feel that the field of obesity has been affected by therapeutic inertia. Of note, obesity may also affect the response to concomitant medications such as low-dose aspirin. Lessons from withdrawn agents such as the cannabinoid receptor antagonist rimonabant include developing compounds with a more targeted action profile (i.e., central vs peripheral, or antagonist versus inverse agonist) as well as careful selection of patients based on individual risk factors. We anticipate that the expanding knowledge base and clinical testing will result in improved outcomes for patients with obesity in the near future.

[Conjugated linoleic acid improves glucose and lipid metabolism in diabetic mice]

OBJECTIVE

To analyze the effect of conjugated linoleic acid (CLA) on glucose and lipid metabolism in obese diabetic (db/db) mice.

METHODS

db/db mice were randomized for treatment with saline or CLA mixture administered intragastrically. The changes in body weight, dietary intake, water intake, oral glucose tolerance, triglyceride and total cholesterol were recorded after the treatments. HE staining and oil red O staining were used to assess liver pathologies and fatty acid content. The expression levels of PPARα, PPARγ, CD36, CHREBP and SREBP-1c were detected using real-time PCR and Western blotting. HepG2 cells were treated with CLA and linoleic acid and the expressions of PPARα, ACC, P-ACC, and CD36 were detected; the level of acetyl-CoA in the cell supernatant was detected using ELISA.

RESULTS

CLA treatment obviously reduced the dietary and water intake of db/db mice, effectively reduced the body weight and decreased serum triglyceride and cholesterol levels (P < 0.05). CLA significantly reduced fasting blood glucose, increased glucose tolerance, reduced the accumulation of lipid droplets in the liver and improved lipid metabolism in db/db mice. The mice showed significantly increased expression of PPARα (P < 0.05) and lowered CD36 expression (P < 0.001) in the liver after CLA treatment. Cellular experiments showed that CLA significantly up-regulated PPARα (P < 0.001) and P-ACC and decreased the expression of CD36 (P < 0.01). ELISA showed that acetyl-CoA was significantly up-regulated in the cells after CLA treatment (P < 0.01).

CONCLUSIONS

The mixture of two conjugated linoleic acid isomers can reduce fasting blood glucose, increase glucose tolerance and improve glycolipid metabolism in db/db mice by enhancing the expression of PPARα, increasing P-ACC and inhibiting CD36 expression.

Effect of weight reduction on glycated haemoglobin in weight loss trials in patients with type 2 diabetes

AIM

To quantify the effect of weight loss on glycated haemoglobin (HbA1c) at group level, based on data from published weight loss trials in overweight and obese patients with type 2 diabetes (T2D).

METHODS

A systematic literature search in MEDLINE, EMBASE and Cochrane CENTRAL (January 1990 through December 2012) was conducted to identify prospective trials of energy-reduced diets, obesity drugs or bariatric surgery in adult, overweight and obese patients with T2D. Based on clinical data with follow-up from 3 to 24 months, a linear model was developed to describe the effect of weight reduction on HbA1c.

RESULTS

The literature search identified 58 eligible articles consisting of 124 treatment groups and 17 204 subjects, yielding a total of 250 data points with concurrent mean changes from baseline in weight and HbA1c. The model-based analyses indicated a linear relationship between weight loss and HbA1c reduction, with an estimated mean HbA1c reduction of 0.1 percentage points for each 1 kg of reduced body weight for the overall population. Baseline HbA1c was a significant covariate for the relationship between weight loss and HbA1c: high HbA1c at baseline was associated with a greater reduction in HbA1c for the same degree of weight loss. The collected trial data also indicated weight-loss-dependent reductions in antidiabetic medication.

CONCLUSIONS

At group level, weight loss in obese and overweight patients with T2D was consistently accompanied by HbA1c reduction in a dose-dependent manner. The model developed in the present study estimates that for each kg of mean weight loss, there is a mean HbA1c reduction of 0.1 percentage points. HbA1c-lowering is greater in populations with poor glycaemic control than in well controlled populations with the same degree of weight loss. This summary of data from previous trials regarding the effect of weight reduction on HbA1c may be used to support the design and interpretation of future studies that aim to demonstrate the efficacy of weight loss interventions for T2D treatment.

Impact on psychosocial outcomes of a nationally available weight management program tailored for individuals with type 2 diabetes: Results of a randomized controlled trial

AIMS

Type 2 diabetes mellitus (T2DM) can substantially decrease quality of life (QOL). This study examined the effects on QOL-relevant psychosocial measures of a widely available commercial weight loss program enhanced for individuals with T2DM.

METHODS

A year-long multi-site randomized clinical trial compared the Weight Watchers (WW) approach, supplemented with phone and email counseling with a certified diabetes educator (CDE), to brief standard diabetes nutrition counseling and education (Standard Care; SC). Participants were 400 women and 163 men (N=279 WW; 284 SC) with T2DM [mean (±SD) HbA_1c 8.32±1%; BMI=37.1±5.7kg/m²; age=55.1 ± 9.1years]. Psychosocial outcomes were assessed at baseline, month 6, and month 12 using a diabetes specific psychosocial measure (Diabetes Distress Scale [DDS]), Impact of Weight on Quality of Life-Lite scale (IWQOL), a generic QOL measure (SF-36), and a depression screen (PHQ-9).

RESULTS

WW participants showed significantly greater improvements than did SC participants on all DDS subscales and total score and on IWQOL total score and physical function, sex life and work domains (all ps<.05). There was no significant treatment effect on SF-36 scores or PHQ-9.

CONCLUSIONS

WW enhanced for individuals with T2DM was superior to SC in improving psychosocial outcomes most specific to T2DM and obesity. Available commercial WL programs, combined with scalable complementary program-specific diabetes counseling, may have benefits that extend to diabetes-related distress and weight-relevant QOL.

Randomized controlled trial of a nationally available weight control program tailored for adults with type 2 diabetes

OBJECTIVE

Modest weight loss from clinical interventions improves glycemic control in type 2 diabetes (T2DM). Data are sparse on the effects of weight loss via commercial weight loss programs. This study examined the effects on glycemic control and weight loss of the standard Weight Watchers program, combined with telephone and email consultations with a certified diabetes educator (WW), compared with standard diabetes nutrition counseling and education (standard care, SC).

METHODS

In a 12-month randomized controlled trial at 16 U.S. research centers, 563 adults with T2DM (HbA_1c 7-11%; BMI 27-50 kg/m² ) were assigned to either the commercially available WW program (regular community meetings, online tools), plus telephone and email counseling from a certified diabetes educator, or to SC (initial in-person diabetes nutrition counseling/education, with follow-up informational materials).

RESULTS

Follow-up rate was 86%. Twelve-month HbA_1c changes for WW and SC were -0.32 and +0.16, respectively; 24% of WW versus 14% of SC achieved HbA_1c <7.0% (P = 0.004). Weight losses were -4.0% for WW and -1.9% for SC (Ps < 0.001). 26% of WW versus 12% of SC reduced diabetes medications (P < 0.001). WW participants had greater reductions in waist circumference (P < 0.001) and C-reactive protein (P = 0.02) but did not differ on other cardiovascular risk factors.

CONCLUSIONS

Widely available commercial weight loss programs with community and online components, combined with scalable complementary diabetes education, may represent accessible and effective components of management plans for adults with overweight/obesity and T2DM.

Combating the dual burden: therapeutic targeting of common pathways in obesity and type 2 diabetes

The increasing prevalence of obesity is contributing substantially to the ongoing epidemic of type 2 diabetes. Abdominal adiposity, a feature of ectopic fat syndrome, is associated with silent inflammation, abnormal hormone secretion, and various metabolic disturbances that contribute to insulin resistance and insulin secretory defects, resulting in type 2 diabetes, and induce a toxic pattern that leads to cardiovascular disease, liver pathologies, and cancer. Despite the importance of weight control strategies in the prevention and management of type 2 diabetes, long-term results from lifestyle or drug interventions are generally disappointing. Furthermore, most of the classic glucose-lowering drugs have a side-effect of weight gain, which renders the management of most overweight or obese people with type 2 diabetes even more challenging. Many anti-obesity pharmacological drugs targeting central control of appetite were withdrawn from the market because of safety concerns. The gastrointestinal lipase inhibitor orlistat was the only anti-obesity drug available until the recent US, but not European, launch of phentermine-controlled-release topiramate and lorcaserin. Improved knowledge about bodyweight regulation opens new prospects for the potential use of peptides derived from the gut or the adipose tissue. Combination therapy will probably be necessary to avoid compensatory mechanisms and potentiate initial weight loss while avoiding weight regain. New glucose-lowering treatments, especially glucagon-like peptide-1 receptor agonists and sodium glucose cotransporter-2 inhibitors, offer advantages over traditional antidiabetic drugs by promoting weight loss while improving glucose control. In this Review, we explore the overlapping pathophysiology and also how various treatments can, alone or in combination, combat the dual burden of obesity and type 2 diabetes.

The importance of weight management in type 2 diabetes mellitus

BACKGROUND

The obesity epidemic is driving the increased prevalence of type 2 diabetes mellitus (T2DM), and the vast majority of patients with T2DM are overweight or obese. Excess body weight is associated with the risk of cardiometabolic complications, which are major causes of morbidity and mortality in T2DM.

AIMS

To review evidence about effects of weight loss in pre-diabetes and established T2DM.

RESULTS

In prediabetes, weight loss has been shown to delay the onset or decrease the risk of T2DM, while in established T2DM weight loss has been shown to improve glycaemic control, with severe calorie restriction even reversing the progression of T2DM. Observational studies support the reduction in cardiovascular risk factors following weight loss in patients with T2DM. However, data from the randomised Look AHEAD trial revealed intensive weight loss interventions did not reduce the rate of cardiovascular events in overweight or obese adults with T2DM, and secondary analyses of other large cardiovascular outcomes trials have also been inconclusive. However, besides cardiovascular risk, other documented benefits of weight loss in T2DM include improvements in quality of life, mobility, and physical and sexual function.

CONCLUSIONS

Physicians should encourage weight loss in all overweight patients with or at risk of T2DM, and should consider the impact on weight when choosing the most appropriate glucose-lowering therapies for these patients.

Strategies for preventing type 2 diabetes: an update for clinicians

Diabetes is a major and growing public health challenge which threatens to overwhelm medical services in the future. Type 2 diabetes confers significant morbidity and mortality, most notably with target organ damage to the eyes, kidneys, nerves and heart. The magnitude of cardiovascular risk associated with diabetes is best illustrated by its position as a coronary heart disease risk equivalent. Complications related to neuropathy are also vast, often working in concert with vascular abnormalities and resulting in serious clinical consequences such as foot ulceration. Increased understanding of the natural history of this disorder has generated the potential to intervene and halt pathological progression before overt disease ensues, after which point management becomes increasingly challenging. The concept of prediabetes as a formal diagnosis has begun to be translated from the research setting to clinical practice, but with continually updated guidelines, varied nomenclature, emerging pharmacotherapies and an ever-changing evidence base, clinicians may be left uncertain of best practice in identifying and managing patients at the prediabetic stage. This review aims to summarize the epidemiological data, new concepts in disease pathogenesis and guideline recommendations in addition to lifestyle, pharmacological and surgical therapies targeted at stopping progression of prediabetes to diabetes. While antidiabetic medications, with newer anti-obesity medications and interventional bariatric procedures have shown some promising benefits, diet and therapeutic lifestyle change remains the mainstay of management to improve the metabolic profile of individuals with glucose dysregulation. New risk stratification tools to identify at-risk individuals, coupled with unselected population level intervention hold promise in future practice.

Present and future: pharmacologic treatment of obesity

Obesity now presents one of the biggest health problems of our times. Diet and exercise are best for both prevention and treatment; unfortunately, both require much discipline and are difficult to maintain. Medications offer a possible adjunct, but their effect is modest, they are limited by side effects, and the weight loss lasts only as long as the drug is being taken, since as soon as treatment is stopped, the weight is regained. Sibutramine, a sympathomimetic medication which was available for long-term treatment, is the most recent of the drugs to be withdrawn from the market due to side effects; in this case it was an increased risk of cardiovascular events. This paper reviews those medications which are available for treatment of obesity, including many of those recently taken off the market. It also discusses some of the newer treatments that are currently being investigated.

Cardiovascular risk-benefit profile of sibutramine

Sibutramine is a combined norepinephrine and serotonin reuptake inhibitor used as an antiobesity agent to reduce appetite and promote weight loss in combination with diet and exercise. At a daily dose of 10-20 mg, it was initially considered to have a good safety profile, as it does not induce primary pulmonary hypertension or adverse effects on cardiac valves, in contrast to previous reports relating to some other antiobesity agents. However, it exerts disparate effects on cardiovascular risk factors. On the one hand, sibutramine may have antiatherogenic activities, as it improves insulin resistance, glucose metabolism, dyslipidemia, and inflammatory markers, with most of these effects resulting from weight loss rather than from an intrinsic effect of the drug. On the other hand, because of its specific mode of action, sibutramine exerts a peripheral sympathomimetic effect, which induces a moderate increase in heart rate and attenuates the reduction in BP attributable to weight loss or even slightly increases BP. It may also prolong the QT interval, an effect that could induce arrhythmias. Because of these complex effects, it is difficult to conclude what the final impact of sibutramine on cardiovascular outcomes might be. Sibutramine has been shown to exert favorable effects on some surrogate cardiovascular endpoints such as reduction of left ventricular hypertrophy and improvement of endothelial dysfunction. A good cardiovascular safety profile was demonstrated in numerous 1- to 2-year controlled trials, in both diabetic and nondiabetic well selected patients, as well as in several observational studies. However, since 2002, several cardiovascular adverse events (hypertension, tachycardia, arrhythmias, and myocardial infarction) have been reported in sibutramine-treated patients. This led to a contraindication of the use of this antiobesity agent in patients with established coronary heart disease, previous stroke, heart failure, or cardiac arrhythmias. SCOUT (Sibutramine Cardiovascular and Diabetes Outcome Study) was designed to prospectively evaluate the efficacy/safety ratio of sibutramine in a high-risk population. The efficacy/safety results of the first 6-week lead-in open period of treatment with sibutramine 10 mg/day were reassuring in 10 742 overweight/obese high-risk subjects (97% had cardiovascular disease, 88% had hypertension, and 84% had type 2 diabetes mellitus). However, the final results of SCOUT showed that long-term (5 years') treatment with sibutramine (10-15 mg/day) exposed subjects with pre-existing cardiovascular disease to a significantly increased risk for nonfatal myocardial infarction and nonfatal stroke, but not cardiovascular death or all-cause mortality. Because the benefit of sibutramine as a weight-loss aid seems not to outweigh the cardiovascular risks, the European Medicines Agency recommended the suspension of marketing authorizations for sibutramine across the EU. The US FDA stated that the drug should carry a 'black box' warning due to an increased risk of stroke and heart attack in patients with a history of cardiovascular disease. In conclusion, concern still persists about the safety profile of sibutramine regarding cardiovascular outcomes, and the drug should not be prescribed for overweight/obese patients with a high cardiovascular risk profile.

Emerging role of GLP-1 receptor agonists in the treatment of obesity

The prevalence of obesity has increased dramatically in recent decades, both in the US and worldwide. Pharmacotherapy can augment the weight-reducing effects of lifestyle modification and can facilitate long-term weight maintenance. However, there is a paucity of pharmacologic agents approved for the treatment of obesity, and the use of existing weight loss medications is frequently limited by contraindications, drug interactions, adverse effects, limited coverage by third-party payers, and cost. In recent years, there has been an increased understanding and appreciation of the role of gastrointestinal hormones in the control of body weight. One such hormone, GLP-1, also plays an important role in glucose homeostasis. GLP-1 receptor agonists, such as exenatide and liraglutide, have been developed and are already approved for the treatment of type 2 diabetes. There has also been interest in the use of GLP-1 receptor agonists for the treatment of obesity in nondiabetic patients. This review explores the potential utility and limitations of exenatide and liraglutide as therapeutic agents for obesity.

Diabesity: therapeutic options

A pathogenic relationship exists between type 2 diabetes and obesity. Over the last decade, the escalation in diabetes cases has paralleled the rapid increase in obesity rates, constituting a global health crisis. Environmental risk factors attributed to the global increase in obesity include the consumption of high-calorie, high-fat foods and inadequate physical activity. Obese individuals may also have a genetic predisposition for obesity. Both diabetes and obesity confer an elevated risk of developing a range of complications and comorbidities, including cardiovascular disease, hypertension and stroke, which can complicate disease management. This review examines the aetiology of the linkages between diabetes and obesity and the range of available therapies. Recent clinical evidence substantiating the efficacy and safety of incretin-based antidiabetic therapies is analysed, in addition to data on antiobesity therapeutic strategies, such as antiobesity agents, behaviour modification and bariatric surgery. Glucose control is often accompanied by weight-neutral or modest weight reduction effects with DPP-4 inhibitor treatment (sitagliptin, vildagliptin, saxagliptin) and weight loss with GLP-1 receptor agonist therapy (exenatide, liraglutide). Studies of antiobesity agents including orlistat, sibutramine and rimonabant have shown attrition rates of 30-40%, and the long-term effects of these agents remain unknown. Bariatric surgical procedures commonly performed are laparoscopic adjustable banding of the stomach and the Roux-en-Y gastric bypass, and have produced type 2 diabetes remission rates of up to 73%. Therapeutic strategies that integrate glycaemic control and weight loss will assume greater importance as the prevalence of diabetes and obesity increase.

Benefits of moderate weight loss in patients with type 2 diabetes

Weight loss is a primary goal of therapy in overweight patients with type 2 diabetes. This review examines whether positive patient outcomes are observed even after relatively small amounts of weight loss, that is, weight loss being more easily attainable in practice. Clinical studies demonstrate that therapeutic benefit rises with increasing weight loss, but that losses as low as 0.45-4 kg (1-9 lb) have positive effects on metabolic control, cardiovascular risk factors and mortality rates. Even the intention to lose weight, without significant success, can improve outcomes in patients with diabetes, presumably because of the healthy behaviours associated with the attempt. The current data support a continued focus on weight loss, including moderate weight loss, as a key component of good care for overweight patients with type 2 diabetes.

The endocanabinnoid system and diabetes - critical analyses of studies conducted with rimonabant

Rimonabant is the first CB1 receptor inhibitor available in the Brazilian market. This new drug has been approved for the treatment of obese or overweight patients associated with cardiovascular risk factors. In this article it is compared the effects of rimonabant treatment in obese patients with cardiovascular risk factors to usual obesity pharmacological treatment.

Behavior therapy for obesity: where are we now?

PURPOSE OF REVIEW

To describe the short-term and long-term results of lifestyle modification for obesity.

RECENT FINDINGS

Randomized controlled trials, which compared different diet and activity interventions were reviewed. Studies that investigated the efficacy of new technologies to provide lifestyle modification, such as web-based delivery, also were examined.

SUMMARY

In general, comprehensive lifestyle modification programs delivered in person induce a loss of approximately 10% of initial weight in 16-26 weeks of treatment. The use of portion-controlled diets, which typically involve the use of meal replacement products, was associated with significantly larger weight losses in the short term. In contrast, interventions delivered via the Internet induced a loss of approximately 5%. However, web-based programs appear to have potential in facilitating the continuation on patient-provider contact, which along with high levels of physical activity, appear to be key strategies for successful long-term weight control. Recent studies also have suggested that the combination of lifestyle modification with long-term use of pharmacotherapy holds promise for maximizing initial weight losses and promoting long-term maintenance.

Treating diabetes and prediabetes by focusing on obesity management

Obesity is associated with an increased risk of developing insulin resistance and type 2 diabetes mellitus (T2DM). In obesity, the adipose cell releases nonesterified free fatty acids, hormones, adipocytokines, and other substances that are involved in insulin resistance. Under normal conditions, the pancreatic islet beta cells increase production of insulin sufficiently to maintain normal blood glucose concentrations despite insulin resistance. However, in genetically predisposed patients, the beta cells eventually become dysfunctional and T2DM develops. The development of T2DM can be delayed or sometimes prevented in individuals with obesity who are able to lose weight. Weight loss can be achieved medically with behavioral therapies that combine diet and exercise treatment or with behavioral therapies combined with weight-loss medications or weight-loss surgery. In this article, we summarize the evidence of obesity management in treating T2DM and prediabetes.

Comparison of dietary conjugated linoleic acid with safflower oil on body composition in obese postmenopausal women with type 2 diabetes mellitus

BACKGROUND

Weight loss may improve glucose control in persons with type 2 diabetes. The effects of fat quality, as opposed to quantity, on weight loss are not well understood.

OBJECTIVE

We compared the effects of 2 dietary oils, conjugated linoleic acid (CLA) and safflower oil (SAF), on body weight and composition in obese postmenopausal women with type 2 diabetes.

DESIGN

This was a 36-wk randomized, double-masked, crossover study. Fifty-five obese postmenopausal women with type 2 diabetes received SAF or CLA (8 g oil/d) during two 16-wk diet periods separated by a 4-wk washout period. Subjects met monthly with the study coordinator to receive new supplements and for assessment of energy balance, biochemical endpoints, or anthropometric variables.

RESULTS

Thirty-five women completed the 36-wk intervention. Supplementation with CLA reduced body mass index (BMI) (P = 0.0022) and total adipose mass (P = 0.0187) without altering lean mass. The effect of CLA in lowering BMI was detected during the last 8 wk of each 16-wk diet period. In contrast, SAF had no effect on BMI or total adipose mass but reduced trunk adipose mass (P = 0.0422) and increased lean mass (P = 0.0432). SAF also significantly lowered fasting glucose (P = 0.0343) and increased adiponectin (P = 0.0051). No differences were observed in dietary energy intake, total fat intake, and fat quality in either diet period for either intervention.

CONCLUSIONS

Supplementation with CLA and SAF exerted different effects on BMI, total and trunk adipose mass, and lean tissue mass in obese postmenopausal women with type 2 diabetes. Supplementation with these dietary oils may be beneficial for weight loss, glycemic control, or both.

The use of sibutramine in the management of obesity and related disorders: an update

Aims:

To review the major trials that evaluated the efficacy and safety of the use of sibutramine for weight loss and the impact of this agent on obesity-related disorders.

Methods and results:

The most important articles on sibutramine up to January 2009 were located by a PubMed and Medline search. Sibutramine reduces food intake and body weight more than placebo and has positive effects on the lipid profile (mainly triglycerides and high density lipoprotein cholesterol), glycemic control and inflammatory markers in studies for up to one year. Preliminary studies showed that sibutramine may also improve other obesity-associated disorders such as polycystic ovary syndrome, left ventricular hypertrophy, binge eating disorder and adolescent obesity. The high discontinuation rates and some safety issues mainly due to the increase in blood pressure and pulse rate have to be considered. Additionally, it has not yet been established that treatment with sibutramine will reduce cardiovascular events and total mortality.

Conclusions:

Sibutramine, in conjunction with lifestyle measures, is a useful drug for reducing body weight and improving associated cardiometabolic risk factors and obesity-related disorders. Studies of longer duration are required to determine the precise indications of the drug, to evaluate safety issues and to assess its efficacy on cardiovascular mortality.

Progress and controversies: treating obesity and insulin resistance in the context of hypertension

Improvements in hypertension treatment and control are challenged by the increasing incidence of metabolic risk factors for hypertension, in particular, obesity and insulin resistance. Such risk factors can increase the severity of hypertension and can interact via a multitude of hormonal and inflammatory pathways. Their presence may affect antihypertensive agent choice with regard to antihypertensive efficacy as well as potential synergistic or antagonistic effects on inflammatory status and progression to diabetes. Furthermore, an increasing number of pharmacologic options are available to promote weight loss and insulin sensitivity that may affect blood pressure directly and indirectly. This review considers the metabolic basis for the complex interactions of hypertension with obesity and insulin resistance, and it assesses the clinical evidence for an impact of weight loss and insulin-sensitizing treatment on blood pressure. Awareness of these pathophysiologic interrelations and their implications for treatment are likely to be of increasing importance for successful blood pressure management.

Current pharmacotherapeutic concepts for the treatment of obesity in adults

Obesity is one of the greatest public health challenges of the twenty-first century. The World Health Organization (WHO) reports that in 2005 approximately 1.6 billion adults were overweight and at least 400 million adults were obese. The prevalence of obesity is still continuing to increase dramatically. Overweight and obese people carry a higher risk for a variety of cardiovascular diseases including hypertension, coronary heart disease, stroke and peripheral occlusive artery disease. Weight loss is considered to be the initial step which helps to prevent or to control the clinical consequences of obesity. In a great number of patients who are not able to reduce weight by means of non-pharmacological measures, drug therapy can assist in reaching the weight management targets. Drug treatment should only be considered as part of a systematic weight management program including dietary and lifestyle changes. This review summarizes current pharmacotherapeutic concepts for the treatment of obesity in adults focusing on efficacy and safety of anti-obesity drugs.

An update on preventive and regenerative therapies in diabetes mellitus

Type 1A (immune-mediated) and type 2 diabetes mellitus are two of the most common severe chronic illnesses, affecting over 230 million people worldwide with an estimated global prevalence of 5.1%. Although type 1 and type 2 diabetes differ greatly in modes of pathogenesis, these illnesses share a common pathology and consequences characterized by loss of functional beta-cell mass and subsequent dysregulation of carbohydrate and lipid metabolism. Since therapy for diabetes and the associated complications poses enormous public health and economic burdens, novel preventive and regenerative therapies have emerged in the past decade with the aim to preserve beta-cell mass and delay the onset of diabetes. The goal of this review is to provide a comprehensive overview of current efforts in the fight against diabetes, and attempts to document all strategies that have emerged in clinical studies within the past 25 years. First, strategies to identify individuals at risk, ranging from whole-genome scans to autoantibody screening, will be discussed. Second, novel approaches to prevent or delay the onset of disease will be covered. Particular focus is given on emerging strategies for individuals at risk for type 1 diabetes that target T-cell regulation and induction of tolerance, while new pharmaceutical concepts in combination with lifestyle interventions are discussed within the scope of type 2 diabetes prevention. Lastly, important efforts to halt disease progression with emphasis on beta-cell regeneration are presented.

Pharmacotherapy for obesity in menopausal women

Weight gain, during and after the menopause is common. Contributing factors include ethnicity, reduced physical activity reduced lean mass, reduced resting metabolic rate and treatment with certain drugs, e.g. steroids, insulin, glitazones. Excess body weight increases the risk of medical conditions including type 2 diabetes, hypertension, osteoarthritis, certain cancers and is associated with increased mortality. This review examines pharmacological approaches to promote weight loss. Pharmacological therapy should be considered as an adjunct to diet and lifestyle changes. The licensed drugs orlistat, sibutramine and rimonabant are discussed. Obesity increases the risk of type 2 diabetes. Thus, the effects of metformin and exenatide are examined.

Management of type 2 diabetes in the obese patient: current concerns and emerging therapies

OBJECTIVES

The aims of this review are (1) to examine the pathophysiologic relationship between type 2 diabetes and obesity, (2) to provide an overview of current and emerging treatments for type 2 diabetes and their effects on body weight.

METHODS

A MEDLINE search was performed for literature published in the English language from 1966 to 2006. Abstracts and presentations from the American Diabetes Association Scientific Sessions (2002-2006) and the European Association for the Study of Diabetes Annual Meetings (1998-2006) were also searched for relevant studies. Preclinical and clinical data were selected for inclusion based on novelty and pertinence to treatment of the obese patient.

FINDINGS

Recent guidelines suggest that all patients with type 2 diabetes should initially receive metformin as well as lifestyle intervention, followed by rapid administration of other oral anti-diabetic agents or insulin if glycemic goals are not met or maintained. Many oral anti-diabetic drugs, and insulin, are associated with weight gain. New agents with anti-diabetic activity that may be advantageous in obese patients with type 2 diabetes have recently become available. These include injectable incretin mimetics, which reduce blood glucose while reducing body weight but commonly cause nausea and vomiting. A new class of oral agents, the dipeptidyl peptidase-4 inhibitors, is weight-neutral and largely devoid of gastrointestinal side-effects. The cannabinoid receptor antagonist rimonabant is the first of a new class of anti-obesity agents that reduces central obesity and improves multiple aspects of vascular risk.

CONCLUSION

New agents offer the prospect of improved glycemic control without weight gain. However, the ultimate roles of these agents in the treatment of obese patients with type 2 diabetes remain to be established.

Cost effectiveness of duloxetine in the treatment of diabetic peripheral neuropathic pain in the UK

OBJECTIVE

The objective of this analysis was to evaluate the cost-effectiveness of duloxetine when considered as an additional treatment option for UK-based patients suffering from diabetic peripheral neuropathic pain.

RESEARCH DESIGN AND METHODS

A decision-analytic model was used to represent the sequential management of patients with diabetic peripheral neuropathic pain. The standard UK treatment strategy was defined as first-line tricyclic antidepressants (amitriptyline), second-line anticonvulsants (gabapentin) and lastly an opioid-related treatment. The cost-effectiveness of duloxetine was evaluated as an additional first, second, third or fourth-line therapy over a 6-month treatment period for a cohort of 1000 patients. Treatment response was modelled based on changes from baseline pain severity using a standard 11-point pain scale (0-10); full response (>or= 50% change), partial response (30-49%) and no response (< 30%). The model was populated with efficacy and discontinuation data using indirect comparisons of treatment efficacy based on relative effects to a common placebo comparator.

RESULTS

The second-line use of duloxetine resulted in cost savings of pound 77,071 for every 1000 treated patients, with an additional 29 patients achieving a full pain response when compared to standard UK treatment. Additional quality-adjusted life years (QALYs) were achieved at 1.88 QALYs per 1000 patients.

CONCLUSIONS

This UK-based economic model suggests that second-line use of duloxetine is a beneficial and cost-effective treatment strategy for diabetic peripheral neuropathic pain.

Secondary prevention of cardiovascular disease in type 2 diabetes and prediabetes: a cardiologist's perspective

Patients with type 2 diabetes mellitus (T2DM) and prediabetes have a substantially greater risk of developing cardiovascular (CV) disease than the general population. This increased risk of CV disease is due to a complex cluster of risk factors including insulin resistance, hyperglycaemia, diabetic dyslipidaemia, hypertension and systemic inflammation. As a result of this cluster of risk factors, life expectancy is reduced by up to 10 years upon diagnosis of T2DM, principally because of fatal CV events. Patients with T2DM are not only more likely to sustain a CV event, but also have a higher risk of a fatal outcome from this event. Therefore, whilst primary prevention is critical in determining the prognosis of patients newly diagnosed with T2DM, many will go on to suffer CV events and represent a high-risk group requiring intensive secondary prevention techniques. Recent data demonstrate that contemporary prevention therapies do not afford equal benefits to T2DM sufferers after acute myocardial infarction compared with their non-diabetic counterparts. This finding highlights the need for more effective secondary preventative strategies to prevent recurrent CV events in patients with T2DM and prediabetes. The cardiologist's role in the multidisciplinary management of T2DM is to improve patient outcomes by optimising use of evidence-based strategies for the prevention of recurrent CV events.

Sibutramine usage in New Zealand: an analysis of prescription data by the Intensive Medicines Monitoring Programme

PURPOSE

To describe patterns of sibutramine usage in New Zealand during the first 3 years of marketing using data acquired during post-marketing safety surveillance.

METHODS

Demographic and prescription data were examined from a nationwide cohort of 17 298 patients prescribed sibutramine between 1 February 2001 and 31 March 2004. Outcome measures were age and sex distribution of the cohort; period prevalence of sibutramine usage for each ethnic group; duration of treatment and reasons for cessation of therapy. Limited BMI data were also examined.

RESULTS

About 0.5% of the NZ population were prescribed sibutramine in the period studied. Overwhelmingly, the highest users of sibutramine were NZ European women aged 30-59 years. Maori and Pacific Peoples were under-represented in the cohort, despite the higher prevalence of obesity among these populations. Sibutramine usage was predominantly short-term: 59% of the cohort used sibutramine for 90 days or less, half of whom used it for only 1 month.

CONCLUSIONS

There has been extensive use of sibutramine in New Zealand. Sibutramine has been relatively under-utilised by Maori and Pacific ethnic groups, compared to New Zealand Europeans, despite their higher prevalence of obesity. A number of factors may have contributed to the predominantly short-term use of this medicine, including the cost of the medicine to the consumer, weight loss not meeting expectations and adverse effects of the medicine.

[Pharmacotherapy of obesity]

Diet, exercise and behavioral therapy are the basics for every treatment of obesity. If lifestyle intervention does not result in a weight loss of 5% within 3 to 6 months, an additional pharmacotherapy can be considered. Treated patients should have a BMI >/=30 kg/m(2) or at least a BMI >/=27 kg/m(2) plus accompanying comorbidities, such as type 2 diabetes, dyslipidemia or hypertension. Current guidelines list orlistat, sibutramine and rimonabant as possible options for the pharmacotherapy of obesity. These compounds result in moderate weight reduction and improvement of cardiovascular risk profile. Especially the improvement of glucose metabolism can be considered as clinically relevant. Different side effects of the various compounds need to be considered before their use. Additional options for the pharmacotherapy of obesity are currently developed, their approval, however, is unlikely to happen within the next couple of years.

[Treatment of type 2 diabetes: revision of current therapeutical options and priorities]

The paradigm of type 2 diabetes mellitus treatment is based in an adequate meal plan and the regular practice of physical exercise. The benefits of these measures are of evident as it is the perseverance in their compliance. In the daily practice, this reality favours the early implementation of a pharmacological therapy that, in the opinion of different experts, would be simultaneous to the introduction of life style changes. In the last years, new drugs have been developed. On the one hand, there are agents with beneficial effects not only on blood glucose control but also on the components of metabolic syndrome. Other drugs, according to different experts, have doubtful therapeutical contribution. The appearance of new drugs to treat obesity, associated with diabetes or not, extends other possibilities of choice to take into account. The great variety of options makes the decision of the adequate therapy more difficult. In the last decade, many therapeutic guidelines have been developed, with convergences and divergences that may mislead the inexpert practitioners. In this review we propose some practical advise in diet and exercise, and an evaluation of the different drugs and rules of intervention proposed in the different therapeutic guidelines. The ultimate goal is to facilitate and direct type 2 diabetes management.

Drugs in the treatment of obesity: sibutramine, orlistat and rimonabant

Background

Modification of lifestyle is the main therapeutical approach in the treatment of obesity, but use to fail on long terms of time. Addition of anti-obesity drugs allows keeping the weight loss during years and improving obesity-related comorbidities.

Methods

This review is an actualisation on efficacy, safety and tolerability of the approved drugs on the long-term treatment of obesity (orlistat and sibutramine). New indications and effects of their use far beyond the weight loss are as well commented. Finally, potential benefits of the administration of CB1 antagonist rimonabant on the weight loss and cardiometabolic risk factors are analysed in detail.

Discussion

A decade of experience on the use of orlistat and sibutramine has demonstrated their higher efficacy on the weight loss when compared to placebo either on adult or teenage population as well as safety and tolerability on long-term administration. Beneficial effects on the lipid profile, glycosilated haemoglobin on diabetic patients, blood pressure and levels of inflammatory cytokines, contribute to decrease the cardiovascular risk on obese patients. Phase III clinical trials using rimonabant show additional benefits to the expected weight loss, mainly reducing visceral fat and cardiometabolic risk factors.

Conclusion

Pharmacological treatment of obesity must be considered as a therapeutical tool that has to be used together with long-term lifestyle changes, contributing to the body weight reduction as well as to the improvement of the cardiometabolic risk related to obesity.

Mono- and disalicylic acid derivatives: PTP1B inhibitors as potential anti-obesity drugs

A series of compounds containing one or two salicylic acid moieties were synthesized, and their efficacy to inhibit the phosphohydrolase activity of PTP1B examined. Some of the methylenedisalicylic acid derivatives were potent inhibitors of PTP1B. Of those derivatives, 3c exhibited about a 14-fold selectivity against TC-PTP, and this compound was tested in a mouse model for its efficacy to prevent diet-induced obesity. It effectively suppressed the increases in body weight and adipose mass, without any noticeable toxic effect. The compound also prevented increases in the plasma triglyceride, cholesterol, and nonesterified fatty acid concentrations; thus, expanding its therapeutic potential to other related metabolic diseases, such as hyperlipidemia and hypercholesterolemia.

Metabolic syndrome management

Overweight, obesity and the metabolic syndrome occur in genetically susceptible individuals with environmental influences, and may be further compounded by other disorders of metabolism or pharmacological therapy that increase insulin resistance or promotes weight gain. Treatment of the metabolic syndrome should focus on treatment on [corrected] each individual component, but first, lifestyle modification, including diet and exercise with weight reduction, should be [corrected] the foundation of any successful treatment regimen for the metabolic syndrome. Pharmacological therapy should be individualized and targeted to normalize blood pressure, HDL cholesterol, triglycerides and glucose values. If successful, comprehensive management of the metabolic syndrome promises to delay or prevent the development of coronary heart disease and Type 2 diabetes mellitus.

A randomized, double-blind, placebo-controlled, multicenter study to assess the efficacy and safety of topiramate controlled release in the treatment of obese type 2 diabetic patients

OBJECTIVE

This is a randomized, placebo-controlled study of the weight-loss efficacy and safety of a controlled-release (CR) formulation of topiramate in overweight and obese patients with type 2 diabetes treated with diet and exercise alone or in combination with metformin.

RESEARCH DESIGN AND METHODS

Patients with type 2 diabetes, BMI > or =27 kg/m2, A1C >6.5 and <11.0%, treated with diet and exercise alone or in combination with metformin monotherapy were enrolled. Patients were randomized to placebo or topiramate CR titrated up to 175 mg/day. Treatment consisted of a 7-week titration phase followed by a 9-week maintenance phase.

RESULTS

A total of 111 subjects were randomized and analyzed. By the end of week 16, patients in the placebo and topiramate groups lost 2.5 and 6.0 kg, which represented 2.3 and 5.8%, respectively, of their baseline body weight (P < 0.001 vs. placebo). A1C improved from a baseline of 7.4% in the placebo and 7.6% in the topiramate groups to 7.1 and 6.7%, respectively, representing a 0.4 and 0.9% reduction from baseline, respectively (P < 0.001 vs. placebo). Topiramate also significantly reduced blood pressure and urinary albumin excretion. Adverse events were predominantly neuropsychiatric or central and peripheral nervous system related.

CONCLUSIONS

Topiramate CR treatment produced significant weight loss and meaningful improvements in A1C and blood pressure in obese patients with type 2 diabetes treated with diet and exercise or in combination with metformin. However, the central nervous system and psychiatric adverse event profile of topiramate CR makes it unsuitable for the treatment of obesity and diabetes.

Drug treatment of the overweight patient

Three medications with approval for long-term use in the treatment of obesity are currently available in the United States. Sibutramine (U.S. Food and Drug Administration [FDA] approved in 1997), orlistat (FDA approved in 1999), and rimonabant (available in Europe and given FDA approvable status in 2006 and expected to be marketed in 2007) represent modern approaches to medications used adjunctively for weight management. As demonstrated in large clinical trials of 2 to 4 years' duration, these medications significantly increase weight loss compared with placebo; weight loss with these drugs reaches a nadir between 20 and 28 weeks; weight loss, averaged 8%-10%, with the placebo contributing 4%-6% of that. Weight maintenance is demonstrated as long as adherence to medication continues. All medications have side effects that need to be considered. For sibutramine, there is a rise in blood pressure and heart rate that may require discontinuation of the drug in a small percent of patients. For orlistat, steatorrhea produces the principal gastrointestinal side effects. Rimonabant appears to have a favorable safety and tolerability profile. Nausea and gastrointestinal symptoms are the chief tolerability issue, but they are usually self-limited. In addition there are several drugs and drug combinations in phase 2 or phase 2 trials that will be reported on in the coming years.

Weight management for type 2 diabetes mellitus: global cardiovascular risk reduction

Most patients with type 2 diabetes mellitus are overweight or obese, and the relation between obesity, especially of the visceral compartment, and the risk for developing diabetes is well recognized. Excessive adipose tissue is associated with insulin resistance as well as the increased expression of proinflammatory cytokines and prothrombotic factors, all of which contribute to elevating the risk for coronary artery disease (CAD). In particular, abdominal obesity, or excess visceral adiposity, has been linked to a cluster of risk factors (high blood pressure, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, and impaired fasting glucose) that constitute the metabolic syndrome, the presence of which confers an increased risk for type 2 diabetes and cardiovascular disease. In fact, a large waist circumference, a surrogate measure of abdominal adiposity, is 1 of the main criteria for diagnosing the metabolic syndrome. Lifestyle modification is the first-line approach to the management of obesity and the metabolic syndrome. However, if patients are unable to achieve a weight loss of 5%-10% of initial body weight and improve cardiometabolic risk factors with lifestyle modification alone, physicians should consider using adjunctive long-term pharmacotherapy. A variety of approved and investigational pharmacologic agents, including sibutramine, orlistat, metformin, and rimonabant, have been shown to reduce weight and ameliorate metabolic syndrome components, thereby reducing cardiovascular risk. Such global risk reduction is crucial for patients with diabetes, in whom CAD is a major cause of mortality.

Revisiting the metabolic syndrome

Metabolic syndrome (MS) refers to the clustering of cardiometabolic risk factors - including abdominal obesity, hyperglycaemia, dyslipidaemia and elevated blood pressure - that are thought to be linked to insulin resistance. MS is associated with increased risk of cardiovascular disease and type 2 diabetes. MS is common, affecting a quarter to a third of adults, and its prevalence is rising, in parallel with increasing obesity and population ageing. Operational definitions of MS have been proposed by the World Health Organization and the National Cholesterol Education Program. Recently, the International Diabetes Federation proposed a global definition that emphasised the importance of central adiposity. In cardiovascular risk assessment, MS encapsulates the contribution of non-traditional risk factors and provides a clinically useful framework for early identification of people at increased long-term risk. It should be used in conjunction with standard algorithms based on conventional risk factors, which better predict short-term risk. Management of MS should emphasise lifestyle interventions (eg, physical activity, healthy diet and weight reduction) to reduce long-term risk of cardiovascular disease and diabetes. Those at increased short-term risk should also have individual risk factors treated according to established guidelines.

Stroke prevention in diabetes and obesity

Stroke is an important cause of morbidity and mortality, and is an economic burden. Diabetes and obesity are two important modifiable risk factors for stroke. Patients with diabetes have a higher incidence of stroke and a poorer prognosis after stroke. Risk-factor modification is the most important aspect of prevention of stroke in diabetes and obesity. This includes lifestyle modifications and different therapeutic modalities to control conditions, such as diabetes, hypertension, dyslipidemia and arrhythmia. Recent landmark studies have shown the beneficial effects of statins in diabetic patients even with close to normal or normal low-density lipoprotein cholesterol. Obesity, which is a risk factor for diabetes, hypertension and hyperlipidemia has been shown to be an independent risk factor for stroke. Increased leptin, dysregulation of adipocyte proteins, increased insulin resistance and C-reactive protein may be factors involved in the increased incidence of cardiovascular morbidity and mortality directly related to obesity. Visceral fat is a much bigger health risk than subcutaneous fat. Lifestyle interventions and pharmacotherapeutic agents have been used to manage obesity. In morbidly obese patients, surgical intervention seems to be the best method of treatment with a long-lasting favorable metabolic outcome. In the 21st Century, with the advanced medical knowledge and the therapeutic modalities available, it should be possible to reduce the incidence of stroke associated with diabetes and obesity.