Sibutramine enhances insulin sensitivity ameliorating metabolic parameters in a double-blind, randomized, placebo-controlled trial

Long-term effects of weight-reducing drugs in people with hypertension

BACKGROUND

This is the third update of this review, first published in July 2009. All major guidelines on treatment of hypertension recommend weight loss; anti-obesity drugs may be able to help in this respect.

OBJECTIVES

Primary objectives: To assess the long-term effects of pharmacologically-induced reduction in body weight in adults with essential hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events).. Secondary objectives: To assess the long-term effects of pharmacologically-induced reduction in body weight in adults with essential hypertension on change from baseline in systolic and diastolic blood pressure, and on body weight reduction.

SEARCH METHODS

For this updated review, the Cochrane Hypertension Information Specialist searched the following databases for randomised controlled trials up to March 2020: the Cochrane Hypertension Specialised Register, CENTRAL, MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. The searches had no language restrictions. We contacted authors of relevant papers about further published and unpublished work.

SELECTION CRITERIA

Randomised controlled trials of at least 24 weeks' duration in adults with hypertension that compared approved long-term weight-loss medications to placebo.  DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, assessed risks of bias, and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using a fixed-effect meta-analysis. When heterogeneity was present, we used the random-effects method and investigated the cause of the heterogeneity.

MAIN RESULTS

This third update of the review added one new trial, investigating the combination of naltrexone/bupropion versus placebo. Two medications, which were included in the previous versions of this review (rimonabant and sibutramine) are no longer considered relevant for this update, since their marketing approval was withdrawn in 2010 and 2009, respectively. The number of included studies in this review update is therefore six (12,724 participants in total): four RCTs comparing orlistat to placebo, involving a total of 3132 participants with high blood pressure and a mean age of 46 to 55 years; one trial comparing phentermine/topiramate to placebo, involving 1305 participants with high blood pressure and a mean age of 53 years; and one trial comparing naltrexone/bupropion to placebo, involving 8283 participants with hypertension and a mean age of 62 years. We judged the risks of bias to be unclear for the trials investigating orlistat or naltrexone/bupropion. and low for the trial investigating phentermine/topiramate. Only the study of naltrexone/bupropion included cardiovascular mortality and morbidity as predefined outcomes. There were no differences in the rates of all-cause or cardiovascular mortality, major cardiovascular events, or serious adverse events between naltrexone/bupropion and placebo. The incidence of overall adverse events was significantly higher in participants treated with naltrexone/bupropion. For orlistat, the incidence of gastrointestinal side effects was consistently higher compared to placebo. The most frequent side effects with phentermine/topiramate were dry mouth and paraesthesia. After six to 12 months, orlistat reduced systolic blood pressure compared to placebo by mean difference (MD) -2.6 mm Hg (95% confidence interval (CI) -3.8 to -1.4 mm Hg; 4 trials, 2058 participants) and diastolic blood pressure by MD -2.0 mm Hg (95% CI -2.7 to -1.2 mm Hg; 4 trials, 2058 participants). After 13 months of follow-up, phentermine/topiramate decreased systolic blood pressure compared to placebo by -2.0 to -4.2 mm Hg (1 trial, 1030 participants) (depending on drug dosage), and diastolic blood pressure by -1.3 to -1.9 mm Hg (1 trial, 1030 participants) (depending on drug dosage). There was no difference in the change in systolic or diastolic blood pressure between naltrexone/bupropion and placebo (1 trial, 8283 participants). We identified no relevant studies investigating liraglutide or lorcaserin in people with hypertension.

AUTHORS' CONCLUSIONS

In people with elevated blood pressure, orlistat, phentermine/topiramate and naltrexone/bupropion reduced body weight; the magnitude of the effect was greatest with phentermine/topiramate. In the same trials, orlistat and phentermine/topiramate, but not naltrexone/bupropion, reduced blood pressure. One RCT of naltrexone/bupropion versus placebo showed no differences in all-cause mortality or cardiovascular mortality or morbidity after two years. The European Medicines Agency refused marketing authorisation for phentermine/topiramate due to safety concerns, while for lorcaserin the application for European marketing authorisation was withdrawn due to a negative overall benefit/risk balance. In 2020 lorcaserin was also withdrawn from the US market. Two other medications (rimonabant and sibutramine) had already been withdrawn from the market in 2009 and 2010, respectively.

Tratamento farmacológico da obesidade: passado, presente e futuro

O tratamento da obesidade deve ser baseado na percepção de que a obesidade é uma enfermidade crônica, neuroquímica e recidivante. Sendo assim, a combinação de eficácia, sustentabilidade de longo prazo e perfil de segurança de excelência devem nortear a utilização dos medicamentos disponíveis assim como das novas moléculas vindouras. No momento, a liraglutida parece ser a mais completa droga para a obesidade como doença crônica, mas certamente deverá ser superada pelos novos peptídeos de múltiplo agonismo e/ou pela combinação de várias medicações ainda não disponíveis em baixas dosagens para pacientes precisa e individualmente selecionados.

Long-term effects of weight-reducing drugs in people with hypertension

BACKGROUND

All major guidelines on antihypertensive therapy recommend weight loss; anti-obesity drugs may be able to help in this respect.

PRIMARY OBJECTIVES

To assess the long-term effects of pharmacologically induced reduction in body weight in adults with essential hypertension on all-cause mortality, cardiovascular morbidity, and adverse events (including total serious adverse events, withdrawal due to adverse events, and total non-serious adverse events).

SECONDARY OBJECTIVES

To assess the long-term effects of pharmacologically induced reduction in body weight in adults with essential hypertension on change from baseline in systolic blood pressure, change from baseline in diastolic blood pressure, and body weight reduction.

SEARCH METHODS

We obtained studies using computerised searches of the Cochrane Hypertension Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE, Ovid EMBASE, the clinical trials registry ClinicalTrials.gov, and from handsearches in reference lists and systematic reviews (status as of 13 April 2015).

SELECTION CRITERIA

Randomised controlled trials in hypertensive adults of at least 24 weeks' duration that compared long-term pharmacologic interventions for weight loss with placebo. 

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed risk of bias, and extracted data. Where appropriate and in the absence of significant heterogeneity between studies (P > 0.1), we pooled studies using fixed-effect meta-analysis. When heterogeneity was present, we used the random-effects method and investigated the cause of heterogeneity.

MAIN RESULTS

After updating the literature search, which was extended to include four new weight-reducing drugs, we identified one additional study of phentermine/topiramate, bringing the total number of studies to nine that compare orlistat, sibutramine, or phentermine/topiramate to placebo and thus fulfil our inclusion criteria. We identified no relevant studies investigating rimonabant, liraglutide, lorcaserin, or naltrexone/bupropion. No study included mortality and cardiovascular morbidity as predefined outcomes. Incidence of gastrointestinal side effects was consistently higher in those participants treated with orlistat versus those treated with placebo. The most frequent side effects were dry mouth, constipation, and headache with sibutramine, and dry mouth and paresthaesia with phentermine/topiramate. In participants assigned to orlistat, sibutramine, or phentermine/topiramate body weight was reduced more effectively than in participants in the usual-care/placebo groups. Orlistat reduced systolic blood pressure as compared to placebo by -2.5 mm Hg (mean difference (MD); 95% confidence interval (CI): -4.0 to -0.9 mm Hg) and diastolic blood pressure by -1.9 mm Hg (MD; 95% CI: -3.0 to -0.9 mm Hg). Sibutramine increased diastolic blood pressure compared to placebo by +3.2 mm Hg (MD; 95% CI: +1.4 to +4.9 mm Hg). The one trial that investigated phentermine/topiramate suggested it lowered blood pressure.

AUTHORS' CONCLUSIONS

In people with elevated blood pressure, orlistat and sibutramine reduced body weight to a similar degree, while phentermine/topiramate reduced body weight to a greater extent. In the same trials, orlistat and phentermine/topiramate reduced blood pressure, while sibutramine increased it. We could include no trials investigating rimonabant, liraglutide, lorcaserin, or naltrexone/bupropion in people with elevated blood pressure. Long-term trials assessing the effect of orlistat, liraglutide, lorcaserin, phentermine/topiramate, or naltrexone/bupropion on mortality and morbidity are unavailable and needed. Rimonabant and sibutramine have been withdrawn from the market, after long-term trials on mortality and morbidity have confirmed concerns about the potential severe side effects of these two drugs. The European Medicines Agency refused marketing authorisation for phentermine/topiramate due to safety concerns, while the application for European marketing authorisation for lorcaserin was withdrawn by the manufacturer after the Committee for Medicinal Products for Human Use judged the overall benefit/risk balance to be negative.

Metabolic syndrome, diabetes, and hyperuricemia

PURPOSE OF REVIEW

To explore the causal relationship between metabolic syndrome, type 2 diabetes and hyperuricemia.

RECENT FINDINGS

The prevalence of hyperuricemia in male adults with metabolic syndrome was increased and a large difference in prevalence of metabolic syndrome also existed in those with hyperuricemia compared with normouricemia. Even in those with normouricemia, higher serum uric acid levels were associated with metabolic syndrome. Serum uric acid was an independent risk factor for incident diabetes, and evidence showed that the patients with both gout and type 2 diabetes exhibited a mutual inter-dependent effect on higher incidences. Furthermore, obese patients often demonstrated insulin resistance and adipose tissue macrophage with low-grade inflammation, which is suggested to be the major contributor. Although alcohol intake is considered a risk for developing hyperuricemia, moderate alcohol intake showed a lower risk for developing type 2 diabetes and insulin resistance. Hyperinsulinemia reduces renal excretion of uric acid on the proximal tubular of the kidney leading to hyperuricemia, which has deleterious effects on endothelial function and on nitric oxide bioavailability, thus causing hyperinsulinemia.

SUMMARY

We found evidence to suggest that insulin resistance plays a potentially key role in the causal relationship between metabolic syndrome, type 2 diabetes and hyperuricemia. Furthermore, it is likely that hyperuricemia and insulin resistance share a bidirectional causal effect.

Long-term effects of weight-reducing drugs in hypertensive patients

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss; anti-obesity drugs might be a helpful option.

PRIMARY OBJECTIVES

To assess the long-term effects of pharmacologically induced reduction in body weight with orlistat, sibutramine or rimonabant on:- all cause mortality - cardiovascular morbidity - adverse events

SECONDARY OBJECTIVES

- changes in systolic and/or diastolic blood pressure - body weight reduction even though sibutramine and rimonabant have been withdrawn from the market.

SEARCH METHODS

Studies were obtained from computerised searches of Ovid MEDLINE, EMBASE, CENTRAL and from hand searches in reference lists and systematic reviews (status as of 17(th) August, 2012).

SELECTION CRITERIA

Randomized controlled trials in adult hypertensive patients with a study duration of at least 24 weeks comparing pharmacologic interventions (orlistat, sibutramine, rimonabant) for weight loss with placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. Studies were pooled using fixed-effect meta-analysis in the absence of significant heterogeneity between studies (p>0.1). Otherwise, we used the random effects method and investigated the cause of heterogeneity.

MAIN RESULTS

After the updated literature search, the number of studies remained the same, with eight studies comparing orlistat or sibutramine to placebo fulfilling our inclusion criteria. No relevant studies investigating rimonabant for weight loss were identified. No study included mortality and cardiovascular morbidity as a pre-defined outcome. Incidence of gastrointestinal side effects was consistently higher in orlistat treated vs. placebo treated patients. Most frequent side effects with sibutramine were dry mouth, constipation and headache. Patients assigned to weight loss diets, orlistat or sibutramine reduced their body weight more effectively than patients in the usual care/placebo groups. Blood pressure reduction in patients treated with orlistat was for systolic blood pressure (SBP): weighted mean difference (WMD): -2.5 mm Hg; 95% CI, -4.0 to -0.9 mm Hg and for diastolic blood pressure (DBP): WMD -1.9 mm Hg; 95% CI, -3.0 to -0.9 mm Hg. Meta-analysis showed DBP increase under therapy with sibutramine: WMD +3.2 mm Hg; 95%CI +1.4 to +4.9 mm Hg.

AUTHORS' CONCLUSIONS

In patients with elevated blood pressure, orlistat and sibutramine reduced body weight to a similar degree. In the same trials, orlistat reduced blood pressure and sibutramine increased blood pressure. No trials investigating rimonabant in people with elevated blood pressure could be included. Long-term trials assessing the effect of orlistat, sibutramine and rimonabant on mortality and morbidity are lacking. Rimonabant and sibutramine have been withdrawn from the market for the time being.

Short-term effects of sibutramine on mineral status and selected biochemical parameters in obese women

The aim of this study was to assess the effect of sibutramine on mineral status and selected biochemical parameters in obese women. The study was conducted on 24 patients who received 15 mg daily doses of sibutramine for 12 weeks, and on 20 patients who received placebo. At the baseline, after the sixth and twelfth weeks of treatment, body weight and blood pressure were measured, the BMI was calculated, and samples of blood and of first morning urine were collected. Serum lipid profiles, glucose levels, and nitric oxide levels were determined. The iron (Fe), copper (Cu), zinc (Zn), calcium (Ca), and magnesium (Mg) present in the serum and urine samples were assessed. The erythrocyte hemolysate of the patients was use to assay the activity of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD). No changes were observed in BMI, blood pressure, or nitric oxide during the study. After 12 weeks of treatment, a decrease was observed in total cholesterol, LDL cholesterol, triglyceride, glucose, and ferritin levels. GSH-Px and SOD activity increased after 12 weeks of sibutramine treatment. The Mg and Cu increases was observed in serum after the sixth and twelfth weeks of treatment. It was found that the Zn level decreased in serum after the twelfth week. The elimination of Ca, Mg, Fe, Zn, and Cu in urine also declined in the twelfth week. No differences were found in the women taking the placebo. In conclusion, we found that sibutramine had a positive effect on lipid and glucose status in obese women. However, the drug disturbed the balance of minerals, especially Zn and Mg, in the subjects.

Long-term effects of weight-reducing drugs in hypertensive patients

BACKGROUND

All major guidelines for antihypertensive therapy recommend weight loss; anti-obesity drugs might be a helpful option.

PRIMARY OBJECTIVES

To assess the long-term effects of pharmacologically induced reduction in body weight with orlistat, sibutramine or rimonabant on:- all cause mortality - cardiovascular morbidity - adverse events

SECONDARY OBJECTIVES

- changes in systolic and/or diastolic blood pressure - body weight reduction

SEARCH STRATEGY

Studies were obtained from computerised searches of Ovid MEDLINE, EMBASE, CENTRAL and from hand searches in reference lists and systematic reviews.

SELECTION CRITERIA

Randomized controlled trials in adult hypertensive patients with a study duration of at least 24 weeks comparing pharmacologic interventions (orlistat, sibutramine, rimonabant) for weight loss with placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. Studies were pooled using fixed-effect meta-analysis in the absence of significant heterogeneity between studies (p>0.1). Otherwise, we used the random effects method and investigated the cause of heterogeneity.

MAIN RESULTS

Eight studies comparing orlistat or sibutramine to placebo fulfilled our inclusion criteria. No relevant studies investigating rimonabant for weight loss were identified. No study included mortality and cardiovascular morbidity as a pre-defined outcome. Incidence of gastrointestinal side effects was consistently higher in orlistat treated vs. placebo treated patients. Most frequent side effects with sibutramine were dry mouth, constipation and headache. Patients assigned to weight loss diets, orlistat or sibutramine reduced their body weight more effectively than patients in the usual care/placebo groups. Blood pressure reduction in patients treated with orlistat was for systolic blood pressure (SBP): weighted mean difference (WMD): -2.5 mm Hg; 95% CI, -4.0 to -0.9 mm Hg and for diastolic blood pressure (DBP): WMD -1.9 mm Hg; 95% CI, -3.0 to -0.9 mm Hg. Meta-analysis showed DBP increase under therapy with sibutramine: WMD +3.2 mm Hg; 95%CI +1.4 to +4.9 mm Hg.

AUTHORS' CONCLUSIONS

In patients with elevated blood pressure, orlistat and sibutramine reduced body weight to a similar degree. In the same trials, orlistat reduced blood pressure and sibutramine increased blood pressure. No trials investigating rimonabant in people with elevated blood pressure could be included. Long-term trials assessing the effect of orlistat, sibutramine and rimonabant on mortality and morbidity are needed.

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.

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.

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.

Effect of hypocaloric diet plus sibutramine treatment on hormonal and metabolic features in overweight and obese women with polycystic ovary syndrome: a randomized, 24-week study

OBJECTIVE

To examine the effect of hypocaloric diet plus sibutramine on body composition, hormonal and metabolic parameters in overweight and obese patients with polycystic ovary syndrome (PCOS).

DESIGN

Open-label, randomized study at an outpatient clinic.

PATIENTS

A total of 59 overweight and obese (18-39 years old) women with PCOS.

MEASUREMENTS

All patients were placed in a hypocaloric diet plus sibutramine (10 mg per day) for the first month and then on a hypocaloric diet plus sibutramine (10 mg per day, group S) or hypocaloric diet only (group D) for the subsequent 6 months. Body composition, hormonal and metabolic features and insulin sensitivity (oral glucose tolerance test, OGTT) were evaluated at baseline and at 3 and 6 months of treatment.

RESULTS

Body weight reduced in both groups but the reduction was greater with sibutramine (-15.4+/-1.1 vs -11.1+/-1.9% in groups S and D, respectively, P<0.05). At 6 months, a greater percent of patients lost more than 10% of initial body weight in group S than D (81 vs 52.9%). In both groups, all women with abnormal OGTT at baseline presented normal glucose tolerance after 6 months. Free androgen index (FAI), glucose area under the curve and fasting triglyceride (TG) concentration were reduced after 6 months in group S only (P<0.05). No changes in cardiovascular risk factors, prolactin and hepatic enzymes levels were observed in both groups.

CONCLUSION

A hypocaloric diet and a diet plus sibutramine both result in significant weight loss in overweight and obese women with PCOS. Patients who received sibutramine showed a greater weight loss and improvement in hyperandrogenemia and insulin sensitivity after 6 months of treatment. The amelioration of insulin resistance in this group could not be totally explained by weight loss. Total testosterone, FAI and TG levels reduction could be a possible mechanism. Finally, sibutramine increased compliance to diet and it was well tolerated from these patients.

Present and future therapeutic strategies in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is found in individuals who do not drink or abuse alcohol and represents a significant health burden for the general community. NAFLD is often associated with one or more features of the metabolic syndrome and has potential for evolution towards non-alcoholic steatohepatitis (NASH), the necro-inflammatory form of liver steatosis. The most worrisome evolutive events in a subgroup of NASH patients include advanced liver fibrosis, cirrhosis, and hepatocellular carcinoma. Pathophysiology of NAFLD/NASH is complex, but studies point to a pre-eminent role of oxidative stress and lipid peroxidation in the liver, including early mitochondrial dysfunction. Changes follow an insulin resistance status with a background of a chronic pro-inflammatory status due to an excess of visceral adiposity. Although no established therapy exists for NAFLD/NASH, potential therapeutic approaches are discussed in this review.

Elevated serum uric acid levels in metabolic syndrome: an active component or an innocent bystander?

Elevated serum uric acid (SUA) levels are commonly seen in patients with the metabolic syndrome (MetS). Several mechanisms, both direct and indirect, connect the increased SUA levels with the established diagnostic criteria of MetS. It is possible that the increased cardiovascular disease risk associated with the MetS is partially attributed to elevated circulating SUA concentration. Several drugs used in the treatment of MetS may alter SUA levels. Thus, lifestyle measures together with the judicious selection of drugs for the treatment of hypertension, dyslipidemia, and insulin resistance associated with MetS may result in a reduction of SUA levels and possibly cardiovascular disease risk. This review summarizes the pathophysiologic association between SUA and MetS and focuses on the prevention of hyperuricemia and its cardiovascular consequences.

Hyperuricemia and Associated Diseases

After introduction of urate-lowering therapy, asympotomatic hyperuricemia was treated with allopurinol or uricosuric agents in the belief that hyperuricemia and/or gout caused chronic kidney disease. Epidemiologic studies in the 1970s, however, failed to confirm the view that hyperuricemia and gout were independent risk factors for chronic kidney disease. As a result, urate-lowering pharmacotherapy is generally not recommended at the present time in the management of asymptomatic hyperuricemia even though recent epidemiological, experimental, and clinical studies have prompted reexamination of a causal role for hyperuricemia (with or without gout) in chronic kidney disease as well as other important disorders including cardiovascular disease, hypertension, and metabolic syndrome. The issue of such a role remains unresolved and this article reviews the current status of the relationship between hyperuricemia and associated disorders.

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.

Prevention and treatment of the metabolic syndrome

The prevalence of the metabolic syndrome is increasing owing to lifestyle changes leading to obesity. This syndrome is a complex association of several interrelated abnormalities that increase the risk for cardiovascular disease and progression to diabetes mellitus (DM). Insulin resistance is the key factor for the clustering of risk factors characterizing the metabolic syndrome. The National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III defined the criteria for the diagnosis of the metabolic syndrome and established the basic principles for its management. According to these guidelines, treatment involves the improvement of the underlying insulin resistance through lifestyle modification (eg, weight reduction and increased physical activity) and possibly by drugs. The coexistent risk factors (mainly dyslipidemia and hypertension) should also be addressed. Since the main goal of lipid-lowering treatment is to achieve the NCEP low-density lipoprotein cholesterol (LDL-C) target, statins are a good option. However, fibrates (as monotherapy or in combination with statins) are useful for the treatment of the metabolic syndrome that is commonly associated with hypertriglyceridemia and decreased high-density lipoprotein cholesterol (HDL-C) levels. The blood pressure target is < 140/90 mm Hg. The effect on carbohydrate homeostasis should possibly be taken into account in selecting an antihypertensive drug. Patients with the metabolic syndrome commonly have other less well-defined metabolic abnormalities (eg, hyperuricemia and raised C-reactive protein levels) that may also be associated with an increased cardiovascular risk. It seems appropriate to manage these abnormalities. Drugs that beneficially affect carbohydrate metabolism and delay or even prevent the onset of DM (eg, thiazolidinediones or acarbose) could be useful in patients with the metabolic syndrome. Furthermore, among the more speculative benefits of treatment are improved liver function in nonalcoholic fatty liver disease and a reduction in the risk of acute gout.

Modulatory role of food, feeding regime and physical exercise on body weight and insulin resistance

Energy intake and expenditure is a highly conserved and well-controlled system with a bias toward energy intake. In times of abundant food supply, individuals tend to overeat and in consequence to increase body weight, sometimes to the point of clinical obesity. Obesity is a disease that is not only characterized by enormous body weight but also by rising morbidity for diabetes type II and cardiovascular complications. To better understand the critical factors contributing to obesity we performed the present study in which the effects of energy expenditure and energy intake were examined with respect to body weight, localization of fat and insulin resistance in normal Wistar rats. It was found that a diet rich in fat and carbohydrates similar to "fast food" (cafeteria diet) has pronounced implication in the development of obesity, leading to significant body weight gain, fat deposition and also insulin resistance. Furthermore, an irregularly presented cafeteria diet (yoyo diet) has similar effects on body weight and fat deposition. However, these rats were not resistant to insulin, but showed an increased insulin secretion in response to glucose. When rats were fed with a specified high fat/carbohydrate diet (10% fat, 56.7% carbohydrate) ad lib or at the beginning of their activity phase they were able to detect the energy content of the food and compensate this by a lower intake. They, however, failed to compensate when food was given in the resting phase and gained more body weight as controls. Exercise, even of short duration, was able to keep rats on lower body weight and reduced fat deposition. Thus, inappropriate food intake with different levels of energy content is able to induce obesity in normal rats with additional metabolic changes that can be also observed 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.