Weight loss with sibutramine improves glycaemic control and other metabolic parameters in obese patients with type 2 diabetes mellitus

Medical Management of Obesity and its Complications

Obesity is increasing and with this comes an increase in Metabolic Disease. Current therapies are effective. We need to establish groups that are experts in “lifestyle therapy” but make sure that they use the very effective adjunctive therapies when indicated. Whilst bariatric surgery is effective for those with Grade III obesity, it is important to realise that medical therapy is very effective for those who are overweight or with lesser degrees of adiposity. There needs to be a proper lifestyle programme and the use of adjunctive treatment when necessary. This approach can reduce weight, reduce cardiovascular risk, help control diabetes and prevent it. We MUST establish proper treatment programmes and follow-up systems. Key words: Approach to treatment, Complications of obesity, Lifestyle management, Obesity pharmacotherapy

Medications for weight reduction

Only two drugs are currently approved for long-term use in the treatment of obesity and four others for short-term use. Evaluating the risk-benefit profile is an essential first step. For individuals who have a low body mass index for whom the risk is small, the risk profile must make the drug acceptable for almost everyone. For higher-risk patients, such as those planning intestinal bypass or who have sleep apnea, a wider range of drugs may be considered. Obesity is a chronic disease that has many causes. Treatment is aimed at palliation-that is, producing and maintaining weight loss. Regardless of the primary site of action, the net effect must be a reduction in food intake or increase in energy expenditure.

Can sibutramine alter systemic blood pressure in obese patients? Systematic review and meta-analysis

CONTEXT

Systemic arterial hypertension is part of the metabolic syndrome resulting from obesity.

OBJECTIVE

To evaluate the effect of sibutramine on overweight and obese patients' blood pressure through a systematic review.

METHODS

All the studies included needed to be randomized controlled trials. The methodological quality of the selected trials was assessed using the criteria described in the Cochrane Handbook. The participants were overweight and obese patients; the intervention was sibutramine compared with placebo. The primary outcome measurement was systolic and diastolic blood pressure and the secondary measurement was blood pressure. Studies were identified by searching the following sources: Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs), Medline, Cochrane reviews, manual searches, personal communication and contact with the pharmaceutical industry. There were no language, date or other restrictions. Data collection and extraction was performed by two reviewers, who independently obtained the full articles of all eligible papers.

RESULTS

Three meta-analyses were produced: 1) systolic blood pressure outcome (eight studies) did not show statistical significance between sibutramine and placebo: weighted mean difference (WMD) 1.57, confidence interval (CI) -0.03 to 3.18; 2) diastolic blood pressure outcome (ten studies) did not show statistical significance between sibutramine and placebo: WMD 1.13, CI -0.49 to 2.76; 3) blood pressure outcome (two studies) also did not show statistical significance between the groups: relative risk (RR) 0.69, CI 0.07 to 7.01.

CONCLUSIONS

The meta-analyses presented in this systematic review show that sibutramine does not have a statistically significant effect on blood pressure, compared with placebo.

Effect of weight-reducing agents on glycaemic parameters and progression to Type 2 diabetes: a review

Weight loss is associated with improvements in glycaemic control and cardiovascular disease risk factors. However, in the diabetic population, weight management is more challenging, in part because of the weight-promoting effects of the majority of glucose-lowering therapies. This review summarizes evidence from 23 placebo-controlled randomized trials, of at least 1 year duration, on the effects of drugs promoting weight loss (orlistat, sibutramine and rimonabant) on glycaemic variables, diabetes incidence and diabetes control. Fifteen studies of non-diabetic subjects were found, eight of which included a longer treatment period. Eight studies in diabetic patients were reviewed. In non-diabetic subjects, weight loss agents led to a significant improvement in fasting glucose, fasting insulin and insulin resistance. In the diabetic population, glycated haemoglobin decreased by 0.28-1.1% with orlistat and 0.6% with sibutramine and rimonabant. Orlistat reduces progression to diabetes in patients with glucose intolerance treated for 4 years (risk reduction of 45%). In summary, despite leading to only modest weight loss after 12 months, agents promoting weight loss have beneficial effects on glycaemic parameters, glycaemic control and progression to diabetes. These additional benefits of weight loss agents need to be highlighted in order to increase their judicious use in clinical practice, although this may be limited by their well-known adverse side effects. The longer-term safety of these agents beyond a few years is yet to be established.

Weight regain and health-related quality of life in postmenopausal women

Weight loss improves health-related quality of life (HRQoL). However, regain after loss is common; little is known about the impact of weight regain on HRQoL in postmenopausal women. Woman on the Move through Activity and Nutrition (WOMAN) is a randomized lifestyle intervention trial of diet, physical activity, and weight loss in 508 postmenopausal women aged 52-62 years. This analysis focused on the women who lost > or =5 lb during the initial phase of the study, baseline to 6 months (n = 248). This cohort was divided into three groups based on subsequent weight change between 6 and 18 months: weight loss (WL; > or =5 lb loss), weight stable (WS; <+/-5 lb change), and weight regain (WR; > or =5 lb gain). HRQoL was measured at baseline, 6, and 18 months using the Short Form-36. Of the 248 women studied, 51 (21%) continued to lose weight after initial weight loss, while 127 (51%) maintained a stable weight, and 70 (28%) regained weight. Between baseline and 6 months, women in WR group had decreased mental health and social-functioning scores, while the WL and WS groups improved in these subscales. Between baseline and 18 months, energy improved most significantly in those with continued weight loss (P = 0.0003). Weight loss was correlated with a small to moderate improvement in perceived general health and energy, which was reversed by weight gain. Further study is needed to investigate the impact of a decline in mental health and social functioning on future weight regain.

Weight changes in type 2 diabetes and the impact of gender

AIMS

Many studies suggest that weight gain occurs during treatment of type 2 diabetes, irrespective of the treatment type. The aim of this study was to address the questions (i) whether weight gain is inevitable in patients treated for type 2 diabetes, and (ii) whether treatment escalation is prompted by a rise in glycaemic control [haemoglobin A 1c (HbA 1c)] or weight gain.

METHODS

A diabetes database was used to identify all patients with type 2 diabetes attending our clinic between 1 January 1990 and 31 December 2000. To facilitate further analysis, independent anonymized database resources were established. Data collected included height, weight, gender, HbA(1c), age and diabetes treatment at each visit.

RESULTS

One thousand and eighty-four patients were included; after 6 months of treatment, patients' average weight had reduced by 1.0 kg (s.d. 4.6) (p < 0.001). Sixty per cent of the patients had either a decrease or no change in weight, while 40% demonstrated a weight gain. Women demonstrated more weight loss than men. After a mean follow-up of 50 months (s.d. 25.7), 439 patients (40%) who received treatment with diet alone, diet followed by metformin or metformin alone demonstrated a maintained weight reduction in addition to improved glycaemic control. A rise in HbA(1c) rather than weight gain prompted treatment change.

CONCLUSIONS

This study provides evidence that weight gain is not a necessary consequence of the treatment of type 2 diabetes. Women were more successful than men in losing weight, and diet, with or without the addition of metformin, was the treatment type most usually associated with weight loss.

Sibutramine-associated adverse effects: a practical guide for its safe use

Obesity is a multifactorial chronic disorder which comprises a serious health problem nowadays. The effective management of obesity is difficult in contemporary societies where abundance of hypercaloric food and sedentary lifestyle is the rule. Apart from lifestyle interventions, which include diet, exercise and behavioural treatment, weight-loss medications can also be used for the management of obesity. Sibutramine, a selective monoamine reuptake inhibitor, is a drug with established efficacy in sustained weight reduction and an overall favourable safety profile. However, its action on the sympathetic nervous system has linked sibutramine to blood pressure and heart rate elevations. These potentially adverse effects as well as other sibutramine-associated side effects and their possible underlying mechanisms are reviewed in the present article. Compelling evidence from the majority of data in the literature shows that sibutramine can be effectively used in conjunction with caloric restriction and exercise in obese patients. Hypertension, if adequately treated and frequently monitored, is not an absolute contraindication for the prescription of sibutramine.

Cardiac remodeling in obesity

The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic.

Orlistat and sibutramine beyond weight loss

BACKGROUND AND AIM

To investigate, through a meta-analysis of clinical trials, the effect of two weight-reducing drugs, such as orlistat and sibutramine, on serum lipid profiles in overweight and obese subjects, independently of weight loss.

METHODS

A systematic search strategy, incorporating the terms orlistat, sibutramine, fat, cholesterol, lipid profile, cardiovascular risk, was developed to identify randomized trials in MEDLINE from inception to the end of May 2005. Trial selection was limited by language of publication (English) and duration (6-12 months).

RESULTS

Fifteen and ten randomized, double-blind, placebo-controlled trials on orlistat and sibutramine respectively, were eligible for inclusion. In the 15 trials with orlistat, mean weight loss showed a significant correlation with mean reduction of total cholesterol (r=0.48; p<0.05), which maintained statistical significance after adjustment for mean weight loss (B=-2.81+/-1.28; p<0.05). Conversely, in the ten trials with sibutramine, treatment was not associated with a significant decrease in cholesterol levels after adjustment for weight loss (B=3.25+/-4.13; p not significant).

CONCLUSION

Orlistat or sibutramine, when individually compared to placebo, are effective in promoting significant weight loss. In addition, orlistat determines a significant reduction of total cholesterol, independent of weight loss itself. These observations indicate that orlistat is a useful adjunctive tool for improving cardiovascular risk factor profiles in overweight and obese patients.

Time to insulin in type-2 diabetes: high hurdles or Santiago way?

The prevalence of obesity has been increasing dramatically in the last decades; the major metabolic complication of obesity is insulin resistance and type-2 diabetes because there are pathogenetic mechanisms linking obesity and type-2 diabetes. Diabetes is also rapidly increasing worldwide; such a description of the key stages in the evolution of type-2 diabetes may be of great interest for implementing antidiabetes treatment. In recent times, type-2 diabetes therapy has been based on drugs, which improve insulin sensibility or stimulate insulin secretion or slow down glucose absorption. Recently, an ADA and EASD consensus has been released to develop a common approach for the management of hyperglycaemia in adults. The development of new classes of blood-glucose-lowering medications to supplement the older therapies, such as lifestyle-directed interventions, insulin, sulfonylureas, and metformin, has increased the different possible options for the treatment of type-2 diabetes. Therapeutic approaches aiming to potentiate the biological effects of incretins include degradation-resistant GLP-1 receptor agonists (incretin mimetics), and inhibitors of dipeptidyl peptidase-IV (DPP-IV) activity (incretin enhancers) will be very useful to slow down type-2 diabetes progression. Weight-loss interventions, such as a hypocaloric diet and physical exercise, in addition to agents such as orlistat, sibutramine and cannabinoid receptor antagonists, may have favourable effects upon fat storage, nutrient metabolism and ultimately glucose tolerance or type-2 diabetes. When the therapeutic target is not achieved, insulin with metformin could be suggested, but is this approach the ideal one for all patients? Perhaps it is possible to delay the initiation of insulin therapy, therefore, the actual and future therapeutical options are considered in the present review.

Obesity: a review of pathogenesis and management strategies

The prevalence of obesity in the developed world is increasing. Approximately 23% of adult Canadians (5.5 million people) are obese. Obesity is associated with an increased risk of developing several comorbid diseases, ranging from cardiovascular diseases to cholelithiasis and nonalcoholic fatty liver disease. The etiology of obesity is multifactorial, involving a complex interaction among genetics, hormones and the environment. The available evidence and recommendations for nonpharmacological management of obesity, including dietary therapy, physical activity and behavioural therapy, in addition to pharmacotherapy are discussed. A brief discussion on endoscopic and surgical procedures is undertaken. Several antiobesity treatment options are available and may be indicated in appropriate situations. Selecting obesity therapy may be guided by body mass index measurements, comorbid illnesses and patient preference.

[Lights and shades in the application of new guidelines for the management of type 2 diabetes mellitus. Practical advice about combined therapy and insulin therapy]

Type 2 diabetes is a disease with an increasing prevalence due to the ageing and sedentary lifestyle of the general population. Its associated with the risk of developing a series of chronic complications in mid/long-term. The current guidelines recommend certain therapy targets that have proven difficult to achieve due to poor compliance or because doctors do not always adhere to expert guidelines. The inability to achieve an adequate glycemic control in the course of diabetes may result in part from the typical conservative stepwise treatment approach that includes monotherapy initiated alter failure of diet and exercise, followed by a combination of oral antiglycemic agents, and ultimately insulin therapy. With respect to insulin therapy, the availability of different analogues as well as the new routes of administration (e.g., inhaled insulin) may allow the early introduction of this therapy, which may be more readily accepted by the patient.

Medical therapy for obesity--current status and future hopes

In accepting any new drug for the treatment of obesity, the safety profile must make it acceptable for almost everyone. Criteria for selecting treatments involve evaluating the risks to the individual from obesity and balancing that against any possible problems with the treatment. Obesity is a chronic disease that has many causes. Cure is rare and treatment is thus aimed at palliation, that is, producing and maintaining weight loss. Wherever the primary site of action may be, however, the net effect must be a reduction in food intake or an increase in energy expenditure.

Metabolic syndrome: treatment of hypertensive patients

Metabolic syndrome (MetSyndr), a constellation of abnormalities [obesity, glucose intolerance, insulin resistance (IR), dyslipidemia (low HDL-cholesterol, high LDL-cholesterol and triglycerides (TG)], and elevated blood pressure (BP)], increases the risk of cardiovascular (CV) disease and premature death. From 10% to 30% of the adult population in industrialized countries has MetSyndr, which effectively predicts the development of type 2 diabetes mellitus (T2D) and CV disease. Because of the complex etiology of MetSyndr, a multi-targeted, integrated therapeutic approach is required to simultaneously treat high BP, obesity, lipid disorders and T2D (if present), to fully protect CV, cerebrovascular and renal systems. If lifestyle modification (weight control, diet, exercise, smoking cessation, moderation of alcohol intake) is ineffective, pharmaco-theraphy should be added to treat simultaneously the lipid- and non-lipid CV risk factors. Patients with HTN and MetSyndr should be started on angiotensin-converting enzyme (ACE) inhibitors, unless contraindicated. The ACE inhibitors and angiotensin receptor blockers (ARBs) reduce the odds of developing new onset T2D and also decrease albuminuria. The ACE inhibitors provide cardioprotective and renoprotective benefits beyond their effect on BP; they also improve IR. The ARBs are renoprotective in addition to being cardioprotective. Long-acting calcium channel blockers are also recommended in hypertensive patients with MetSyndr; these drugs also improve IR. Thiazides (at low doses) and selected ss-blockers can be given to patients with HTN and MetSyndr. Celiprolol in combination with diuretics has a favorable effect on glucose tolerance and IR in patients with HTN and MetSyndr, and spironolactone added to ACE inhibitor or ARB therapy provides additional reno- and CV protective benefits in patients with diabetic nephropathy. Carvedilol, a ss-blocker with vasodilating properties, added to ACE inhibitor or ARB therapy, is effective in preventing worsening of microalbuminuria in patients with HTN and MetSyndr; it also improves IR and glycemic control. Most patients eventually require two or more antihypertensive drugs to reach BP goal. It is recommended that therapy in patients whose BP is more than 20/10 mm Hg above target at diagnosis be initiated with a combination of antihypertensive drugs, administered either as individual drugs or as fixed-dose formulations. Treatment with fixed-dose combinations, such as irbesartan + hydrochlorothiazide provides good BP control in more than two-thirds of hypertensive patients with MetSyndr. Lipid and BP targets are reached in a high percent of patients with HTN and CV disease treated with a combination of amlodipine + atorvastatin. In conclusion, hypertensive patients with the MetSyndr be treated aggressively for each component of the syndrome to provide CV, cerebrovascular and renal protection.

Effects of lifestyle intervention on health care costs: Improving Control with Activity and Nutrition (ICAN)

OBJECTIVE

To evaluate program and health care costs of a lifestyle intervention in a high-risk obese population.

DESIGN

Twelve-month randomized controlled trial comparing lifestyle case management to usual care.

SUBJECTS/SETTING

Health plan members (n=147) with obesity (body mass index >/=27) and type 2 diabetes.

INTERVENTION

Lifestyle case management entailed individual and group education, support, and referrals by registered dietitians. Those in the usual-care group received educational material.

MAIN OUTCOME MEASURES

Medical and pharmaceutical health care costs reimbursed by the participant's primary insurance company.

STATISTICAL ANALYSIS

Total costs were modeled using the four-equation model using previous year cost as a predictor.

RESULTS

Net cost of the intervention was $328 per person per year. After incorporating program costs, mean health plan costs were $3,586 (95% confidence interval [CI]: -$8,036, -$25, P<0.05) lower in case management compared to usual care. The difference was driven by group differences in medical (-$3,316, 95% CI: -$7,829 to -$320, P<0.05) but not pharmaceutical costs (-$239, 95% CI: -$870 to $280, not statistically significant), with fewer inpatient admissions and costs among case management compared with usual care (admission prevalence: 2.8% vs 22.5% respectively, P<0.001).

CONCLUSION

Addition of a modest-cost, registered dietitian-led lifestyle case-management intervention to usual medical care did not increase health care costs and suggested modest cost savings among obese patients with type 2 diabetes. Larger trials are needed to determine whether these results can be replicated in a broader population. The findings can be judiciously applied to support that the addition of a registered dietitian-led lifestyle case-management program to medical care does not increase health care costs.

Effect of gastric bypass operation on Framingham and actual risk of cardiovascular events in class II to III obesity

BACKGROUND

Obesity is known to be a major risk factor for cardiovascular diseases. There are few studies in the literature assessing the effect of bariatric procedures on longterm risk of cardiovascular events. The aim of this study was to determine the effect of gastric bypass operation on actual and Framingham risk of coronary heart disease (CHD) events in class II to III obesity.

STUDY DESIGN

In a cohort of subjects with class II to III obesity, we used the observed change in CHD risk factors and risk models derived from the Framingham data equation to calculate the predicted 10-year absolute and relative risk of CHD after gastric bypass operation. The risk predicted by the Framingham model was then compared with the actual incidence of CHD events of the cohort.

RESULTS

Five-hundred patients were included in the study. The 1-year mean excess body weight loss was 68.7% +/- 22%. There was a substantial reduction in prevalence of diabetes from 28% to 6% (p = 0.001). Compared with baseline, the average 10-year absolute risk of cardiac events decreased from 5.4% at baseline to 2.7% at 1 year after operation (p = 0.001). A similar risk reduction was observed in subgroups defined by diabetes status and gender. Gastric bypass decreased absolute risk of cardiac events by a mean of 63% (p = 0.0001) in diabetics and 56% (p = 0.001) in male patients. The cohort actual rate of CHD events was 1% (5 of 500). At the 5-year horizon, this was considerably (p = 0.001) lower than the predicted rate before gastric bypass operation.

CONCLUSIONS

Gastric bypass operation is effective in reducing actual and the 10-year Framingham risk of CHD events in individuals with class II to III obesity. The major estimated risk reduction was observed in male patients with type 2 diabetes.

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.

Adiposopathy is a more rational treatment target for metabolic disease than obesity alone

Current guidelines recommend that weight-loss therapy should be primarily based upon specific body mass index (BMI) cut-off limits. However, in the adipocentric paradigm, it is acknowledged that co-morbidities, such as type 2 diabetes mellitus, hypertension, and dyslipidemia, occur at all levels of BMI. Excessive fat mass (adiposity) in genetically susceptible individuals results in fat dysfunction (adiposopathy), which then contributes to metabolic disorders that increase the risk of atherosclerotic cardiovascular disease. In this paradigm, the term "anti-obesity" treatment might best be replaced by "anti-adiposopathy" treatment, wherein the focus is not based solely on BMI, but instead directed towards physiologically improving fat cell function and clinically improving the metabolic health of patients. This may occur through appropriate diet, physical exercise, and other lifestyle changes, and/or from drug therapies. Cannabinoid receptor antagonists and peroxisome proliferator activated receptor agonists are examples of agents that physiologically improve fat function and clinically improve metabolic disease.

Dietary and medical therapy of obesity

Surgery is not a cure for obesity but is an effective tool for limiting food consumption. If severely obese patients do not respond to a treatment plan that includes nutritional, exercise, and behavioral interventions plus antiobesity drugs, bariatric surgery may be appropriate. Proper diet selection after bariatric surgery involves more than the energy value and macronutrient composition. Adequate vitamin and mineral composition of the diet is essential to ensure that surgery improves nutritional status. Malabsorption is present to some extent with most surgeries. Therefore, diet after surgery should be monitored closely for adequacy by a nutritionist.

Effect of Sibutramine on Blood Pressure in Patients with Obesity and Well-Controlled Hypertension or Normotension

OBJECTIVE

To assess the short-term effects of sibu-tramine on blood pressure (BP) and heart rate (HR) in normotensive and controlled hypertensive obese patients by using ambulatory blood pressure monitoring (ABPM).

METHODS

Before and 5 to 7 days after the initiation of sibutramine treatment (10 mg or 15 mg daily), when steady-state concentrations of sibutramine had been reached, ABPM was performed in 81 obese patients. Of this overall study group, 47 patients (26 with normoten-sion and 21 with controlled hypertension) received sibu-tramine in a dosage of 10 mg/day, and 34 patients (18 with normotension and 16 with controlled hypertension) received sibutramine in a dosage of 15 mg/day.

RESULTS

Office-measured systolic and diastolic BPs in normotensive and controlled hypertensive groups of patients with obesity were not significantly different before and after treatment with both doses of sibutramine. ABPM results for normotensive obese groups showed that mean systolic and diastolic BPs were not significantly different after treatment with either 10-mg or 15-mg daily doses of sibutramine, in comparison with baseline. Similarly, in the controlled hypertensive obese groups, the ABPM results were not significantly different before and after sibutramine treatment. Moreover, the mean HR did not change significantly after versus before sibutramine treatment in both dosage groups.

CONCLUSION

Sibutramine did not induce or exacerbate hypertension and had no effect on HR in normotensive and controlled hypertensive obese patients when used in either of two suggested daily doses (10 mg or 15 mg).

Sibutramine improves insulin sensitivity without alteration of serum adiponectin in obese subjects with Type 2 diabetes

AIM

To evaluate the effect of sibutramine on weight loss, insulin sensitivity and serum adiponectin levels in obese patients with Type 2 diabetes.

METHODS

This study is a randomized, double-blind, placebo-controlled parallel comparison study of sibutramine 15 mg/day and placebo. Forty-eight eligible obese patients with Type 2 diabetes (age between 30 and 75 years with body mass index > or = 27 kg/m(2)) were randomly assigned to receive either placebo (n = 24) or sibutramine (15 mg/day) (n = 24) for 6 months. Fifteen subjects in each group underwent meal tests and modified insulin suppression tests before and after 6 months' treatment.

RESULTS

After 6 months of sibutramine treatment statistically significant changes from baseline were observed for body weight (85.4 +/- 2.5 vs. 82.9 +/- 2.4 kg, P < 0.005) and body mass index (32.0 +/- 0.7 vs. 31.4 +/- 0.6 kg/m(2), P < 0.05) without a significant alteration of waist-hip ratio (W/H), blood pressure, heart rate, glycaemic parameters or lipid profiles. The steady-state plasma glucose (SSPG) level during the modified insulin suppression test was significantly reduced in the sibutramine group (17.33 +/- 2.92 vs. 14.29 +/- 4.19 mmol/l, P < 0.05) despite similar steady-state plasma insulin (SSPI) concentrations. In addition, serum adiponectin and C-reactive protein (CRP) levels remained unchanged, although modest weight reduction was achieved after sibutramine treatment. There were also no significant correlations between changes in serum adiponectin and reduction of SSPG or body weight. Daily ambient plasma insulin and glucose concentrations in response to a test meal were not significantly different in subjects receiving sibutramine treatment.

CONCLUSIONS

We conclude that treatment with sibutramine 15 mg once daily effectively reduces weight and enhances insulin sensitivity without alteration of serum adiponectin levels in obese patients with Type 2 diabetes.

Effects of sibutramine in overweight, poorly controlled Chinese female type 2 diabetic patients: a randomised, double-blind, placebo-controlled study

To assess the efficacy of sibutramine 15 mg once daily as weight reduction in overweight and obese (body mass index > 25 kg/m2) Chinese female type 2 diabetic patients and to evaluate the influence of weight loss on diabetic control, a randomised, double-blind, placebo-control, 12-week study was conducted. Chinese female type 2 diabetic patients, poorly controlled glucose levels and HbA(1C) > 8% were randomly assigned to two groups. In addition to their hypoglycaemic agents (maximal doses of sulphonylureas and metformin), one group (n = 30) received a sibutramine 15 mg once daily for 12 weeks, and the other (n = 30) received placebo for the same period. Comparing the changes that occurred after 12 weeks in the sibutramine and placebo groups, the former showed significantly greater reduction in body weight (2.5 vs. 0.1 kg, p < 0.05), fasting plasma insulin level (28.8 vs. 2.4 pmol/l, p < 0.01), 2-h postprandial blood glucose after standard test meal (3.2 vs. 1.1 mmol/l, p < 0.01), insulin resistance (5.1 vs. 0.2, p < 0.01), HbA1C (1.7% vs. 0.2%, p < 0.05), triglyceride (0.43 vs. 0.12 mmol/l, p < 0.05) and total cholesterol (0.52 vs. 0.08 mmol/l, p < 0.05). No significant differences were found between treatment groups in blood pressure and heart rate. The addition of sibutramine to diet and oral hypoglycaemic therapy resulted in significant weight loss and improvement in metabolic parameters in the treatment group. Sibutramine should be considered for use alongside diet and oral hypoglycaemic therapy in Chinese overweight and obese women with poorly controlled type 2 diabetes.

Two-year outcome of a combination of weight loss therapies for type 2 diabetes

OBJECTIVE

To evaluate the effects over 2 years of a weight loss program combining several weight loss strategies on weight loss and diabetes control in overweight subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 59 overweight or obese individuals with type 2 diabetes were randomly assigned to either a combination therapy weight loss program for 2 years (C therapy) or a standard therapy weight loss program for 1 year followed by a combination therapy weight loss program in the 2nd year (S/C therapy). C therapy combined the use of meal replacement products, repetitive intermittent low-calorie-diet weeks, and pharmacologic therapy with sibutramine. Outcome measures included changes in weight, glycemic control, plasma lipids, blood pressure, and body composition over 2 years.

RESULTS

A total of 48 participants (23 in the C therapy group and 25 in the S/C therapy group) completed 2 years of study. After 2 years, the C therapy group had weight loss of 4.6 +/- 1.2 kg (P < 0.001) and a decrease in HbA(1c) of 0.5 +/- 0.3% (P = 0.08) from baseline. At 2 years, the C therapy group had significant reductions in BMI, fat mass, lean body mass, and systolic blood pressure. The S/C therapy group showed changes in weight and HbA(1c) in year 2 of the study that were similar to those demonstrated by the C therapy group in year 1.

CONCLUSIONS

This combination weight loss program resulted in significant weight loss and improved diabetes control over a 2-year period in overweight subjects with type 2 diabetes.

A randomized study of orlistat in combination with a weight management programme in obese patients with Type 2 diabetes treated with metformin

AIMS

To assess the effects of orlistat vs. placebo, in combination with a weight management programme, on weight loss and metabolic control in obese patients with Type 2 diabetes.

METHODS

Patients treated with either metformin alone or metformin in combination with sulphonylurea were randomized to double-blind treatment with orlistat or placebo (120 mg) three times daily, combined with a mildly reduced calorie diet and a weight management programme for 52 weeks. Changes in body weight, anthropometry, glycaemic control and lipid profile were assessed.

RESULTS

After 52 weeks, orlistat-treated patients achieved an almost threefold greater reduction in weight compared with placebo recipients (-5.0% vs. -1.8%; P<0.0001). The decrease in waist circumference was significantly greater with orlistat than placebo (-4.8 cm vs. -2.8 cm; P=0.0022). Orlistat treatment was also associated with significantly greater reductions in haemoglobin A(1c) (-1.1% vs. -0.2%; P<0.0001), fasting plasma glucose (-1.9 mmol/l vs. -0.3 mmol/l; P<0.0001), total cholesterol (-0.2 mmol/l vs. 0.1 mmol/l; P=0.03) and apolipoprotein B (-0.08 g/l vs. 0.01 g/l; P=0.0085) and greater improvements in beta-cell function (P=0.031) and insulin resistance (P=0.001) assessed using the homeostasis model assessment (HOMA). Similar results were obtained for subgroups of patients treated with metformin alone or metformin in combination with sulphonylurea. Orlistat treatment reduced the requirement for anti-diabetic medication more than placebo.

CONCLUSIONS

Orlistat, in combination with a reduced calorie diet and a weight management programme, promotes weight loss and clinically relevant improvements in glycaemic control and other cardiovascular risk factors in obese patients with Type 2 diabetes.

A structured review of randomized controlled trials of weight loss showed little improvement in health-related quality of life

OBJECTIVE

To estimate the effect of weight-loss interventions on health-related quality of life (HrQoL) in randomized controlled trials (RCTs); to conduct a meta-analysis of weight-loss treatment on depressive symptoms; and, to examine methodological and presentation issues that compromise study validity.

STUDY DESIGN AND SETTING

We conducted a structured review of 34 RCTs with weight-loss interventions that reported the relationship between HrQoL and treatment at two or more time points. We also evaluated study quality.

RESULTS

Trials lasted 6 weeks to 208 weeks and evaluated behavioral, surgical, or pharmacologic interventions. Nine of 34 trials showed HrQoL improvements in generic measures. Obesity-specific measures were more likely to show improvement in response to treatment than non-obesity-specific measures. Meta-analysis showed no treatment effect on depressive symptoms. Most trials tracked loss to follow-up and conducted intent-to-treat analysis, but only four trials concealed recruitment staff to randomization and 14 blinded the investigation team to randomization.

CONCLUSION

HrQoL outcomes, including depression, were not consistently improved in RCTs of weight loss. The overall quality of these clinical trials was poor. Better-designed RCTs using standardized HrQoL measures are needed to determine the extent to which weight loss improves HrQoL.

Avaliação do efeito da sibutramina sobre a saciedade por escala visual analógica em adolescentes obesos

Inicialmente empregadas para mensuração de sintomas álgicos, as escalas visuais analógicas (EVAs) podem ser também um instrumento útil para avaliação da saciedade. O agente antiobesidade sibutramina, ao contrário dos anorexígenos, parece exercer seu efeito de redução de ingestão alimentar principalmente por estímulo da saciedade. Com o objetivo de avaliar o efeito da sibutramina sobre a saciedade, utilizamos uma EVA em adolescentes obesos que participaram de um estudo duplo-cego randomizado, comparando sibutramina 10mg com placebo. Cada paciente recebeu 13 escalas para serem preenchidas em intervalos de uma hora, num único dia, das 9 às 21h. Uma dieta com déficit de 500kcal diárias foi dividida em 3 refeições, com horários previamente estipulados: 9:30h, 12:30h, 18:30h. A partir da pontuação obtida em cada uma das escalas, construiu-se um gráfico de linha representativo da pontuação média de saciedade ao longo do dia. Comparando-se a área sob a curva dos 2 grupos, encontramos 4.609 ± 1.309 para o grupo tratado com sibutramina e 4.141 ± 1.432 para o grupo placebo (p= NS). Desta forma, a sibutramina não parece apresentar efeito sobre a saciedade de adolescentes obesos, pelo menos quando avaliado através de uma EVA.

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

OBJECTIVE

The aim of this study was to provide a comprehensive meta-analysis of randomized controlled clinical studies on the effects of sibutramine on weight loss and glycemic control in obese subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Controlled clinical trials assessing the effect sizes of sibutramine on weight loss effects on glycemia in obese subjects with type 2 diabetes were identified and reviewed using the Cochrane Library, Medline, EMBASE, and a manual search.

RESULTS

Eight placebo-controlled, double-blind, randomized trials of sibutramine were included. After sibutramine treatment, the decrease in body weight and waist circumference was significantly greater than in the placebo group. Fasting blood glucose and HbA(1c) significantly decreased after sibutramine treatment. Treatment benefits were seen in plasma triglycerides and HDL, without significant variations in serum total and LDL cholesterol. No differences in systolic blood pressure between the sibutramine and the placebo groups were seen, while recording of diastolic blood pressure and heart rate showed that sibutramine produced a small increase relative to placebo.

CONCLUSIONS

A pharmacological approach in a weight management program for patients with type 2 diabetes may be helpful in glycemic control and in the management of other risk factors. Sibutramine may help improve glucose control because it is conducive to weight loss. The reviewed data on the effect of sibutramine further enforce the recommendations that weight management may be the most important therapeutic task for most obese subjects with type 2 diabetes.

Long-term pharmacotherapy for obesity

Obese patients unable to achieve significant weight loss with lifestyle changes alone may require drug therapy, and such therapy may be needed long term lest weight lost be regained. In the United States, only sibutramine and orlistat are available for the long-term treatment of obesity. Clinical trials have shown that both drugs can induce and maintain weight loss, even in patients with comorbid conditions such as hypertension or type 2 diabetes. Their use must be combined with behavior modification and a structured meal plan, however, for patients to reap the full benefits of such treatment.

Sibutramine and the management of obesity

Sibutramine is a selective serotonin and noradrenaline re-uptake inhibitor approved for the long-term management of obesity. Its primary mechanism of action is increased satiety, although some evidence also suggests increased energy expenditure could play a role in sibutramine-induced weight loss. It has established general efficacy in long-term trials, with clinically-approved doses of 10 and 15 mg. Sibutramine has also been studied in a number of unique populations, including obese controlled hypertensives, diabetics and ethnic minorities, further establishing its effectiveness. However, it does have a consistent effect of increasing blood pressure and pulse. Thus, blood pressure and heart rate should be monitored in patients using sibutramine and it may not be applicable in obese patients with significant cardiovascular disease.

A review of the metabolic effects of sibutramine

BACKGROUND

Obesity is associated with an increased incidence of diabetes, hypertension, dyslipidaemia and coronary artery disease. Current management strategies of obesity include lifestyle management strategies of obesity include lifestyle interventions and pharmaco therapy. Sibutramine is a drug with established efficacy in weight reduction and maintenance of weight loss. It reduces food intake and attenuates the fall in reduces food intake and attenuates the fall in metabolic rate associated with weight loss.

OBJECTIVE

To review the metabolic effects associated with sibutramine use.

METHODS

Relevant articles were identified through a Medline search (up to December 2004).

RESULTS

Weight loss with sibutramine treatment is associated with improved insulin sensitivity and a fall in glycosylated haemoglobin levels in type 2 diabetic patients. In most trials sibutramine exerted favourable effects on lipids, especially exerted favourable effects on lipids, especially on high density lipoprotein (HDL) cholesterol and triglycerides, as well as on the total:HDL cholesterol ratio. Sibutramine also lowers serum uric acid concentrations. Furthermore, this drug seems to favourably influence adipocytokines; it reduces serum leptin and resistin levels and increases adiponectin levels. Sibutramine also exerts a beneficial effect on hyper androgenaemia in obese women with polycystic ovary syndrome. Preliminary findings also suggest that weight loss following treatment with sibutramine is useful in patients with non-alcoholic fatty liver disease (NAFLD).

CONCLUSION

Weight loss following sibutramine administration is associated with several favourable metabolic effects.

Agonist diversity in 5-HT(2C) receptor-mediated weight control in rats

RATIONALE

Food intake and energy expenditure are the two main determinants of body weight. Given that 5-HT(2C) receptor agonists are reported to have effects on both energy expenditure and food intake, this strongly suggests that 5-HT(2C) receptor agonists have excellent potential for development as antiobesitiy drugs. One important issue in antiobesity drug development is whether the effects of the compound are maintained during chronic drug treatment.

OBJECTIVES

The purpose of the present study was to investigate the effect of repeated oral administration of three 5-HT(2C) receptor agonists, m-chlorophenylpiperazine (mCPP), d(S)-2-(6-chloro-5-fluoroindol-1-yl)-1-methylethylamine (RO60-0175) and (S)-2-(7-ethyl-1H-furo[2,3-g]indazol-1-yl)-1-methylethylamine (YM348), on food intake and energy expenditure in rats.

RESULTS

In the food intake study, mCPP, RO60-0175 and YM348 decreased food intake in a dose-dependent manner on day 1 of administration. On day 14 of repeated administration, the hypophagic effect of YM348 was lost and that of mCPP was reduced. In contrast, the hypophagic effect of RO60-0175 was maintained even after repeated administration. The hypophagic effects of all agonists were significantly inhibited by a 5-HT(2C) receptor antagonist, SB242084. In contrast to the hypophagic effects, no drug tolerance developed with respect to the hyperthermic effects of mCPP, RO60-0175, and YM348. The hyperthermic effects of these drugs were also inhibited by SB242084.

CONCLUSIONS

Together, the difference between compounds in their hypophagic effects and the similarity in their hyperthermic effects suggest a diversity in agonists in 5-HT(2C) receptor-mediated weight control in rats.

Pharmacotherapy for weight loss in adults with type 2 diabetes mellitus

BACKGROUND

Obesity is closely related to type 2 diabetes and long-term weight reduction is an important part of the care delivered to obese persons with diabetes.

OBJECTIVES

To assess the efficacy of pharmacotherapy for weight loss in adults with type 2 diabetes.

SEARCH STRATEGY

Computerized searches were performed of MEDLINE (January 1966 to May 2004), EMBASE (January 1974 to May 2004, Web of Science (January 1981 to May 2004, and other electronic bibliographic databases, supplemented with hand searches of reference lists and selected journals.

SELECTION CRITERIA

Randomized, controlled trials were included where pharmacotherapy was used as the primary strategy for weight loss among adults with type 2 diabetes. Published and unpublished literature in any language and with any study design was included.

DATA COLLECTION AND ANALYSIS

Two reviewers abstracted data and the quality of included studies was evaluated by assessing potential attrition, as well as selection and measurement bias, and a Jadad score was obtained. Effects were combined using a random effects model.

MAIN RESULTS

A sufficient number of studies were available for a quantitative synthesis for fluoxetine, orlistat, and sibutramine. Twenty two randomized controlled trials were included in the review, with a total of 296 participants for fluoxitine, 2036 for orlistat, and 1047 for sibutramine. Pharmacotherapy produced modest reductions in weight for fluoxetine (5.1 kg (95% confidence interval [CI], 3.3 - 6.9) at 24 to 26 weeks follow up; orlistat 2.0 kg (CI, 1.3 - 2.8) at 12 to 57 weeks follow-up, and sibutramine 5.1 kg (CI, 3.2 - 7.0) at 12 to 52 weeks follow-up. Glycated hemoglobin also modestly and significantly reduced for fluoxetine and orlistat. Gastrointestinal side effects were common with orlistat; tremor, somnolence and sweating with fluoxetine; and palpitations with sibutramine. Some studies, using a variety of study designs, were available on other drugs and a significant decrease in weight was noted in three studies of mazindol, one of phenmetrazine, two of phentermine. No studies were identified that fit inclusion criteria for pseudophedrine, ephedra, sertraline, yohimbine, amphetamine or its derivatives, bupropion, topiramate, benzocaine, threachlorocitric acid, sertraline, and bromocriptine.

AUTHORS' CONCLUSIONS

Fluoxetine, orlistat, and sibutramine can achieve statistically significant weight loss over 12 to 57 weeks. The magnitude of weight loss is modest, however, and the long-term health benefits remain unclear. The safety of sibutramine is uncertain. There is a paucity of data on other drugs for weight loss or control in persons with type 2 diabetes.

Reduction of body weight and co-morbidities by orlistat: The XXL--Primary Health Care Trial

AIM

The aim of this postmarketing surveillance (PMS) study was to investigate the effect of an orlistat therapy under the everyday conditions of our health care system.

METHODS

11 131 women and 4418 men from Germany [mean age 48 years, mean body mass index (BMI) 34.7 kg/m(2) and mean duration of obesity 13.7 years] were included. The patients were predominantly cared for by general practitioners. Four fifths of the patients reported having obesity-associated co-morbidities. All patients were advised to take orlistat 120 mg three times daily.

RESULTS

After a mean treatment duration of 7.1 months, both women and men lost 10.7% of their baseline weight (87% lost > 5% weight and 51% lost > 10% weight). All cardiovascular risk factors improved markedly, and the intake of concomitant medications was either reduced or discontinued. Compared with baseline, 65% of the patients assessed their general state of health to have improved. For more than 90% of their patients, physicians described the success of the treatment as satisfactory, and most patients (62%) were willing to continue with the treatment.

CONCLUSIONS

The results obtained in this naturalistic PMS study were comparable with the results of randomised and placebo-controlled studies, which were performed predominantly in special care centres. Therefore, without any risk of adversely affecting the quality of treatment provided, the treatment of obese patients with orlistat may be transferred to general practitioners.

Diabesity

Weight reduction has been shown to improve glycemic control and cardiovascular risk factors associated with insulin resistance in obese individuals with type 2 diabetes mellitus. Therapeutic options for these patients include promoting weight loss (non-pharmacologic and pharmacologic treatment) and improving glycemic control, as well as treating common associated risk factors such as arterial hypertension and dyslipidemias. This article provides an overview of anti-obesity drugs used in the treatment of obese individuals with type 2 diabetes. The most widely investigated drugs, sibutramine and orlistat, result in modest, clinically worthwhile weight loss, with demonstrable improvements in many co-morbidities, among them, type 2 diabetes. Clinical trials with these anti-obesity medications in cohorts of obese diabetic patients have been reviewed as well as cathecolaminergic agents (diethylpropion [amfepramone], fenproporex, mazindol, ephedrine-caffeine combination), serotoninergic drugs (fenfluramine, dexfenfluramine, fluoxetine), and other drugs that have some action on weight loss (the antidiabetic agent metformin, anti-epileptic agents topiramate and zonisamide, and the antidepressive bupropion [amfebutamone]). These trials show variable benefits in terms of effects on glucose profiles.

Clinical Implications of Obesity With Specific Focus on Cardiovascular Disease

Obesity adversely affects cardiac function, increases the risk factors for coronary heart disease, and is an independent risk factor for cardiovascular disease. The risk of developing coronary heart disease is directly related to the concomitant burden of obesity-related risk factors. Modest weight loss can improve diastolic function and affect the entire cluster of coronary heart disease risk factors simultaneously. This statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism reviews the relationship between obesity and the cardiovascular system, evaluates the effect of weight loss on coronary heart disease risk factors and coronary heart disease, and provides practical weight management treatment guidelines for cardiovascular healthcare professionals. The data demonstrate that weight loss and physical activity can prevent and treat obesity-related coronary heart disease risk factors and should be considered a primary therapy for obese patients with cardiovascular disease.

Current and investigational antiobesity agents and obesity therapeutic treatment targets

Public health efforts and current antiobesity agents have not controlled the increasing epidemic of obesity. Investigational antiobesity agents consist of 1) central nervous system agents that affect neurotransmitters or neural ion channels, including antidepressants (bupropion), selective serotonin 2c receptor agonists, antiseizure agents (topiramate, zonisamide), some dopamine antagonists, and cannabinoid-1 receptor antagonists (rimonabant); 2) leptin/insulin/central nervous system pathway agents, including leptin analogues, leptin transport and/or leptin receptor promoters, ciliary neurotrophic factor (Axokine), neuropeptide Y and agouti-related peptide antagonists, proopiomelanocortin and cocaine and amphetamine regulated transcript promoters, alpha-melanocyte-stimulating hormone analogues, melanocortin-4 receptor agonists, and agents that affect insulin metabolism/activity, which include protein-tyrosine phosphatase-1B inhibitors, peroxisome proliferator activated receptor-gamma receptor antagonists, short-acting bromocriptine (ergoset), somatostatin agonists (octreotide), and adiponectin; 3) gastrointestinal-neural pathway agents, including those that increase cholecystokinin activity, increase glucagon-like peptide-1 activity (extendin 4, liraglutide, dipeptidyl peptidase IV inhibitors), and increase protein YY3-36 activity and those that decrease ghrelin activity, as well as amylin analogues (pramlintide); 4) agents that may increase resting metabolic rate ("selective" beta-3 stimulators/agonist, uncoupling protein homologues, and thyroid receptor agonists); and 5) other more diverse agents, including melanin concentrating hormone antagonists, phytostanol analogues, functional oils, P57, amylase inhibitors, growth hormone fragments, synthetic analogues of dehydroepiandrosterone sulfate, antagonists of adipocyte 11B-hydroxysteroid dehydrogenase type 1 activity, corticotropin-releasing hormone agonists, inhibitors of fatty acid synthesis, carboxypeptidase inhibitors, indanones/indanols, aminosterols, and other gastrointestinal lipase inhibitors (ATL962). Finally, an emerging concept is that the development of antiobesity agents must not only reduce fat mass (adiposity) but must also correct fat dysfunction (adiposopathy).

Orlistat, sibutramine, or combination therapy: which performs better on waist circumference in relation with body mass index in obese patients?

The aim of this study was to evaluate decrease in waist circumference in obese patients receiving different anti-obesity treatments. The study was designed as a short-term (12 weeks), open-label, and randomized trial. Eighty six patients (70 females, 81.4%; mean age 41.09+/-8.73 years, mean BMI 36.1+/-4.3 kg/m2) were randomized to four different therapy groups. The primary outcome parameters were waist circumference and body mass index (BMI). The therapy groups were a) diet+sibutramine 1 x 10 mg/d (n=22), b) diet+orlistat 3 x 120 mg/d (n=25), c) combination of diet+sibutramine+orlistat (n=20) and d) diet (n=19). Combination therapy was more effective than diet and orlistat mono-therapy (p<0.0001 for all), but not significantly superior to sibutramine mono-therapy (p=0.072) in decreasing BMI. Sibutramine mono-therapy was significantly more effective in inducing BMI decrease compared with orlistat mono-therapy (p=0.039). The association between change in BMI and change in waist circumference was strongest in the orlistat mono-therapy group (P interaction=0.003). This means that patients taking orlistat experienced more decrease in waist circumference (3.4 cm, R2=0.29) per unit decrease in BMI compared to patients under combination therapy (2.6 cm, R2=0.25, P interaction = 0.015) and patients taking sibutramine (1.8 cm, R2=0.19, P interaction=0.026). In the diet therapy group decline in waist circumference was independent of BMI (1.9 cm, R2=0.02, P interaction=0.076). Although combination therapy and sibutramine mono-therapy were more effective in decreasing BMI, reduction in waist circumference and BMI was most significantly associated with the orlistat mono-therapy group. This may hint at the possibility of orlistat inducing weight loss mainly in the abdominal area targeted to reduce cardiovascular risk.

Health-related quality of life in a randomised placebo-controlled trial of sibutramine in obese patients with type II diabetes

OBJECTIVE

We evaluated the effects of 12-month treatment with sibutramine 15 mg daily compared with placebo on health-related quality of life (HRQL) in obese type II diabetes patients. We examined the associations between the changes in HRQL and in weight, glycaemic control, and haemodynamic variables. We also explored the predictive value of HRQL and its changes early during treatment.

DESIGN

A randomised clinical trial. The subjects were enrolled in a 2-week single-blind run-in period with a modestly hypocaloric diet (700 kcal daily deficit) and then randomised to receive either sibutramine 15 mg (n=114, 60% female) or placebo (n=122, 58% female) once daily with the hypocaloric diet for 12 months.

SUBJECTS

Obese (mean BMI 36 kg/m(2) and age 54 y) type II diabetes patients untreated with antidiabetic medications.

MEASUREMENTS

The main outcome measures included body weight and HRQL (the RAND 36-Item Health Survey 1.0).

RESULTS

The mean weight loss was greater in the sibutramine group (-7.1 kg) than in the placebo group (-2.6 kg, P<0.001). The baseline HRQL was relatively high. There were no significant differences between the treatment groups in glycaemic control or in any of the RAND-36 scales during the study. The scores on physical functioning (PF) and health change (HC) since last year improved in both groups and this improvement was related to weight loss. When HRQL changes were examined in categories of weight loss, the scores on PF and HC increased with >/=5% weight loss, but the scores on vitality (V) and general health (GH) increased only after >/=15% weight loss. Decrease in HbA1c was associated with increases in the scores of PF, GH, V, mental health, and HC. In the sibutramine group, the increase in diastolic blood pressure was associated with the decrease in the scores of PF, physical role functioning, emotional role functioning (ERF), social functioning (SF), and bodily pain. High baseline scores on ERF and SF, and low scores on V predicted weight loss at 12 months. Also, increasing scores on PF and V during the first 3 months predicted weight loss at 12 months. The sum of four dichotomised HRQL variables (baseline ERF >/=75=1 and <75=0; baseline SF>/=80=1 and <80=0; 3-month change in PF>0=1 and </=0=0; 3-month change in V>0=1 and </=0=0) predicted weight loss: In the group with sum 0, the mean(s.d.) weight change at 12 months was 0.0(2.6)% and with sum 4 it was -9.0(8.1)% of baseline weight.

CONCLUSION

Despite the superior weight loss, sibutramine 15 mg daily did not produce HRQL benefits over placebo when measured with the generic RAND-36 in obese type II diabetes patients. PF and HC since last year improved with >/=5% weight loss, but >/=15% weight loss was needed to achieve a cluster of HRQL improvements. The decrease in HbA1c was associated with many HRQL benefits. Poor baseline HRQL and the improvement observed in the first months of treatment may prove to be useful in predicting success in long-term weight loss.

Antiobesity effect of YM348, a novel 5-HT2C receptor agonist, in Zucker rats

The purpose of the present study was to investigate the potency of (S)-2-(7-ethyl-1H-furo[2,3-g]indazol-1-yl)-1-methylethylamine (YM348), a 5-HT2C receptor agonist, as an antiobesity agent in Zucker rats. Single oral administration of YM348 at 0.1, 0.3, 1 and 3 mg/kg significantly reduced food intake in a dose-dependent manner. This effect of YM348 on food intake was inhibited by SB242084, a selective 5-HT2C receptor antagonist. In addition, single administration of YM348 significantly increased body temperature and calorie expenditure at doses of 0.3, 1 and 3 mg/kg, and 1 and 3 mg/kg p.o., respectively. The increasing effect of YM348 on body temperature and calorie expenditure was inhibited by SB242084. Chronic subcutaneous infusion of YM348 (3 and 30 mg/kg/day) for 2 weeks also decreased food intake. However, this hypophagic effect of YM348 was marked during the initial week of infusion but only minor in the second. In contrast, no diminution of effect on body temperature and calorie expenditure was seen on repeated administration of YM348 (1 mg/kg p.o.). Two weeks' subcutaneous infusion of YM348 (3 and 30 mg/kg/day) resulted in a significant decrease in body weight gain throughout the experiment. These results suggest that the maintenance of thermogenesis contributed to the reduced body weight by YM348. The ability of YM348 to decrease body weight in Zucker rats suggests its strong potential for development as an antiobesity agent in humans.

A new evidence-based model for weight management in primary care: the Counterweight Programme

BACKGROUND/AIMS

Obesity has become a global epidemic, and a major preventable cause of morbidity and mortality. Management strategies and treatment protocols are however poorly developed and evaluated. The aim of the Counterweight Programme is to develop an evidence-based model for the management of obesity in primary care.

METHODS

The Counterweight Programme is based on the theoretical model of Evidence-Based Quality Assessment aimed at improving the management of obese adults (18-75 years) in primary care. The model consists of four phases: (1) practice audit and needs assessment, (2) practice support and training, (3) practice nurse-led patient intervention, and (4) evaluation. Patient intervention consisted of screening and treatment pathways incorporating evidence-based approaches, including patient-centred goal setting, prescribed eating plans, a group programme, physical activity and behavioural approaches, anti-obesity medication and weight maintenance strategies. Weight Management Advisers who are specialist obesity dietitians facilitated programme implementation. Eighty practices were recruited of which 18 practices were randomized to act as controls and receive deferred intervention 2 years after the initial audit.

RESULTS

By February 2004, 58 of the 62 (93.5%) intervention practices had been trained to run the intervention programme, 47 (75.8%) practices were active in implementing the model and 1256 patients had been recruited (74% female, 26% male, mean age 50.6 years, SD 14). At baseline, 75% of patients had at one or more co-morbidity, and the mean body mass index (BMI) was 36.9 kg/m(2) (SD 5.4). Of the 1256 patients recruited, 91% received one of the core lifestyle interventions in the first 12 months. For all patients followed up at 12 months, 34% achieved a clinical meaningful weight loss of 5% or more. A total of 51% of patients were classed as compliant in that they attended the required level of appointments in 3, 6, and 12 months. For fully compliant patients, weight loss improved with 43% achieving a weight loss of 5% or more at 12 months.

CONCLUSION

The Counterweight Programme is an evidence-based weight management model which is feasible to implement in primary care.

A benefit-risk assessment of sibutramine in the management of obesity

Obesity is a multifactorial, chronic disorder that has reached epidemic proportions in most industrialised countries and is threatening to become a global epidemic. Clinical management of obese patients is complex and serious doubts have arisen with regard to safety and efficacy of drug therapy. Following the withdrawal of fenfluramine and dexfenfluramine in 1997, interest has focused on novel anti-obesity drugs. Pharmacological approaches to the management of obesity can, in broad terms, use different distinct strategies: firstly, to reduce energy intake; secondly, to increase energy expenditure; and thirdly, to alter the partitioning of nutrients between fat and lean tissue. Sibutramine is a serotonin-noradrenaline (norepinephrine) reuptake inhibitor indicated for the management of obesity in conjunction with a reduced calorie diet. The pharmacological mechanisms by which sibutramine exerts its weight loss effect are likely due to a combination of reduced appetite, feelings of satiety and possibly the induction of thermogenesis. The efficacy of sibutramine for inducing initial weight loss and the subsequent maintenance of weight loss is well proven in short- and long-term clinical trials of up to 2 years' duration. Most individual placebo-controlled trials and pooled estimates found that the drug produced statistically significant greater weight loss than placebo at all observed endpoints (weighted mean difference for weight change at 8 weeks: -3.4 kg; mean difference range for weight change at 6 months: -4.0 to -9.1 kg; and at 1 year: -4.1 to -4.8 kg). The most frequent dosage regimen in these trials was 10-20 mg daily. Findings suggested a dose-effect relationship in terms of weight loss. Sibutramine was also associated with better weight maintenance relative to placebo (statistically significant difference). Results from mainly small trials showed that sibutramine produced more favourable outcomes in terms of loss of fat mass, reduction in body mass index and loss of > or = 5-10% of initial bodyweight. The most commonly reported adverse effects of sibutramine are headache, constipation and nausea. Certain adverse events associated with the nervous system, including dizziness, dry mouth and insomnia, are reported by > 5% of patients receiving sibutramine. Increases in blood pressure and heart rate were possible adverse effects that require regular monitoring especially in obese hypertensive patients. Neither left-sided cardiac valve disease nor primary pulmonary hypertension was associated with the use of sibutramine. The assessment of the benefit-risk profile of sibutramine remained positive, although the product must be kept under regular review.