leptin and sibutramine

Sibutramine is an anti-obesity medication whose effects on weight loss have been widely explored. Moreover, limited number of studies also evidenced its correlates on adipokines and proinflammatory markers; however, their results have not been conclusive. Hence, a systematic review and meta-analysis of available evidence was conducted in order to calculate the effect size of sibutramine therapy on C-reactive protein (CRP), leptin and adiponectin concentrations. Seven randomized clinical trials with a total of 601 subjects met the eligibility criteria. Random effect meta-analysis evidenced a significant decrease in plasma levels of CRP and leptin (weighted mean difference [WMD] -15.58%, 95% confidence interval [95%CI]: -28.84, -2.33, p=0.021 and WMD -9.25, 95%CI: -15.73, -2.78, p=0.005, respectively) and increase of adiponectin (WMD 9.86%, 95%CI: 1.76, 17.96, p=0.017) following sibutramine therapy. Subgroup analysis showed a greater CRP-lowering effect of sibutramine with doses <15 mg/day (WMD -17.26%, 95%CI: -31.02, -3.5, p=0.014) compared with doses .15 mg/day (WMD 6.01%, 95%CI: -43.38, 55.40, p=0.811). In meta-regression analysis, changes in CRP were found to be independent of baseline or percentage change in body mass index. These results suggest a significant improvement of plasma CRP, leptin and adiponectin levels following treatment with sibutramine. Possible impacts and relevance of these alterations on cardiovascular risk profile remain to be clarified, especially in post-hoc analyses of sibutramine outcome trials among people without pre-existing cardiovascular disease.

Topics: Adiponectin; Anti-Obesity Agents; Body Mass Index; Body Weight; C-Reactive Protein; Cyclobutanes; Humans; Leptin; Randomized Controlled Trials as Topic

Mutations in genes involved in energy balance regulation within the central nervous system lead to monogenic forms of obesities. Individuals with these mutations are characterized by early-onset obesity and in some cases by endocrine abnormalities. Carriers of leptin gene mutations are able to normalize their body weight after daily subcutaneous leptin administration. Pharmacotherapy targeting the specific-gene deficiencies has not clinically been tested in other monogenic obesities. Mutations in the melanocortin 4 receptor gene (MC4R) represent the most common monogenic cause of human obesity. Several treatment options have been investigated in subjects with MC4R mutations. Few studies showed that an intensive life-style intervention induces similar weight reduction in MC4R mutation carriers in comparison to MC4R mutation noncarriers. However, long-term body weight maintenance is hardly ever achieved in MC4R mutation carriers. Sibutramine, serotonin and noradrenalin reuptake inhibitor, in MC4R mutation carriers induced weight reduction and improved cardiometabolic health risks. This result was also found in our homozygous MC4R mutation carrier. In vitro studies of melanocortin agonists efficiently activate mutated MC4R with impaired endogenous agonist functional response and thus, further research in the development of drugs for MC4R mutations is needed. An administration of intranasal adrenocorticotropic hormone was not shown to be effective in subjects with pro-opiomelanocortin gene mutations. Bariatric surgery has also been performed in few of MC4R mutation carriers. After gastric banding, lower body weight reduction and worse improvement of metabolic complications was found in MC4R mutation carriers versus noncarriers. However, preliminary results suggest that diversionary operations as gastric bypass represent a suitable method also for MC4R mutation carriers. In conclusion, the management of monogenic obesities still remains a challenge.

Topics: Bariatric Surgery; Body Mass Index; Body Weight; Child; Cyclobutanes; Energy Metabolism; Heterozygote; Homozygote; Humans; Leptin; Mutation; Obesity; Pro-Opiomelanocortin; Receptor, Melanocortin, Type 4; Weight Loss

Obesity is a chronic disease, and it requires chronic therapy. Hypertension, dyslipidemia, diabetes and cardiovascular diseases are leading causes of mortality in the modern world. All of them are strongly linked to obesity. While treating obesity, those conditions are also managed. Obese patients should always be treated through lifestyle interventions, though the results of such interventions are modest. Pharmacotherapy is a second step in the treatment of obesity, approved only when weight loss targets were not reached through lifestyle intervention. During the history of antiobesity drugs, many of them were withdrawn because of their side effects. Various guidelines recommend prescribing drug therapy for obesity through consideration of the potential benefits and limitations. Orlistat deactivates intestinal lipase and inhibits intestinal fat lipolysis. It is actually the only drug on the European market approved for the treatment of obesity. Orlistat therapy reduces weight to a modest extent, but it reduces the incidence of diabetes beyond the result achieved with lifestyle changes. Recently, some effective antiobesity drugs like sibutramine and rimonabant have been removed from the market due to their side effects. The new combination of topimarate and fentermine is approved in the US but not in Europe. The cost effectiveness of long-term pharmacotherapy of obesity is still an unresolved question.

Topics: Anti-Obesity Agents; Appetite; Combined Modality Therapy; Comorbidity; Cost-Benefit Analysis; Cyclobutanes; Diabetes Mellitus, Type 2; Diet, Diabetic; Drug Combinations; Exercise Therapy; Fructose; Gastrointestinal Hormones; Humans; Incretins; Insulin; Insulin Secretion; Intestines; Lactones; Leptin; Life Style; Models, Biological; Neuropeptides; Obesity; Orlistat; Phentermine; Phytotherapy; Piperidines; Plant Preparations; Pyrazoles; Rimonabant; Topiramate

Currently, obesity presents one of the biggest health problems. Management strategies for weight reduction in obese individuals include changes in life style such as exercise and diet, behavioral therapy, and pharmacological treatment, and in certain cases surgical intervention. Diet and exercise are best for both prevention and treatment, but both require much discipline and are difficult to maintain. Drug treatment of obesity offer a possible adjunct, but it may only have modest results, limited by side effects; furthermore, the weight lowering effects last only as long as the drug is being taken and, unfortunately, as soon as the administration is stopped, the weight is regained. These strategies should be used in a combination for higher efficacy. Drugs used to induce weight loss have various effects: they increase satiety, reduce the absorption of nutrients or make metabolism faster; but their effect is usually moderate. In the past, several drugs were used in the pharmacological therapy of weight reduction including thyroid hormone, dinitrophenol, amphetamines and their analogues, e.g. fenfluramine, At present, only orlistat is available in the long term treatment (≥ 24 weeks) of obesity as sibutramine and rimonabant were withdrawn form the market. Several new anti-obesity drugs are being tested at present, and liraglutide, a GLP-1 analogue (incretin mimetic), is the most promising one.

Topics: Amides; Anti-Obesity Agents; Anticonvulsants; Antidepressive Agents; Basal Metabolism; Benzazepines; Benzoxazines; Body Mass Index; Bridged Bicyclo Compounds, Heterocyclic; Ciliary Neurotrophic Factor; Clinical Trials as Topic; Combined Modality Therapy; Cyclobutanes; Dexfenfluramine; Fatty Acids; Female; Fenfluramine; Glucagon-Like Peptide 1; Human Growth Hormone; Humans; Intestinal Absorption; Lactones; Leptin; Life Style; Liraglutide; Male; Norepinephrine; Obesity; Obesity, Morbid; Orlistat; Piperidines; Pyrazoles; Pyridines; Receptor, Melanocortin, Type 4; Rimonabant; Satiation; Serotonin; Sodium-Glucose Transport Proteins; Sucrose; Thyroid Hormones

It has been long known that the frequency of overweight and obese people is higher among depressed and bipolar patients than in the general population. The marked alteration of body weight (and appetite) is one of the most frequent of the 9 symptoms of major depressive episode, and these symptoms occur during recurrent episodes of depression with a remarkably high consequence. According to studies with representative adult population samples, in case of obesity (BMI over 30) unipolar or bipolar depression is significantly more frequently (20-45%) observable. Since in case of depressed patients appetite and body weight reduction is observable during the acute phase, the more frequent obesity in case of depressed patients is related (primarily) not only to depressive episodes, but rather to lifestyle factors, to diabetes mellitus also more frequently occurring in depressed patients, to comorbid bulimia, and probably to genetic-biological factors (as well as to pharmacotherapy in case of medicated patients). At the same time, according to certain studies, circadian symptoms of depression give rise to such metabolic processes in the body which eventually lead to obesity and insulin resistance. According to studies in unipolar and bipolar patients, 57-68% of patients is overweight or obese, and the rate of metabolic syndrome was found to be between 25-49% in bipolar patients. The rate of metabolic syndrome is further increased by pharmacotherapy. Low total and HDL cholesterol level increases the risk for depression and suicide and recent studies suggest that omega-3-fatty acids possess antidepressive efficacy. Certain lifestyle factors relevant to healthy metabolism (calorie reduction in food intake, regular exercise) may be protective factors related to depression as well. The depression- and possibly suicide-provoking effect of sibutramine and rimonabant used in the pharmacotherapy of obesity is one of the greatest recent challenges for professionals and patients alike.

Topics: Anti-Obesity Agents; Antidepressive Agents; Appetite Depressants; Appetite Regulation; Bipolar Disorder; Circadian Rhythm; Cyclobutanes; Depression; Depressive Disorder, Major; Dietary Carbohydrates; Energy Intake; Ghrelin; Humans; Hypothalamo-Hypophyseal System; Insulin Resistance; Leptin; Obesity; Piperidines; Pituitary-Adrenal System; Pyrazoles; Rimonabant; Seasonal Affective Disorder; Sleep Wake Disorders; Surveys and Questionnaires; Weight Gain; Weight Loss

Appetite suppressants have been available as weight-reducing aids for over 50 years. The first discovered was amphetamine, which was potent, but possessed undesirable side effects (it is a stimulant and elevates blood pressure). Subsequently, a variety of appetite drugs was developed, all structurally related to amphetamine, but mostly lacking unwanted side effects. Until recently, fenfluramine (FEN) was the most widely used; presently, sibutramine is the most commonly used appetite suppressant. While these appetite suppressants are effective at reducing hunger and food intake when given as a single dose or for short periods of time, their effectiveness diminishes when administered chronically. The biological mechanisms underlying this tolerance have not been carefully studied, but many possibilities have been identified, including the down-regulation in brain of neurotransmitter receptors that might mediate the action of these drugs and adaptive responses of the appetite control circuitry in brain. To date, however, few studies have examined these possibilities in any detail. This article focuses on the question of why appetite suppressants lose efficacy, when given chronically, because this issue is important to the development of the next generation of appetite suppressants. Chronic efficacy should be an issue studied relatively early in the drug development process. This issue is of particular relevance, since obesity treatment is now recognized as a long-term, not a short-term, process. If appetite suppressants are to become a more important tool in obesity treatment, agents that do not lose efficacy when administered for extended periods of time must be identified.

Topics: Animals; Appetite Depressants; Body Weight; Cyclobutanes; Drug Tolerance; Eating; Fenfluramine; Humans; Leptin; Obesity; Rats; Time Factors; Weight Loss

The relentless rise in the prevalence of obesity predicts an exponential increase in the incidence of obesity-related complications. Medical and surgical treatments are necessary to prevent and treat obese co-morbidities, thereby avoiding disability and premature death. Interventions for obesity should be evaluated not by weight loss alone but against the new incidence in obesity-related co-morbidities, their remission or improvement. In combination with lifestyle measures, currently available pharmacological therapies -- rimonabant, orlistat and sibutramine -- achieve 5-10% weight loss, although a return to baseline is the norm after cessation of medication. All these agents demonstrate approximately 0.5% reduction in HbA1c in diabetic subjects; orlistat also reduces the new incidence of type 2 diabetes. Modest improvement in lipid profiles and reduced calculated cardiovascular risk is observed, but data on improvement of other co-morbidities are sparse. In contrast, surgical procedures that restrict food ingestion and/or curtail the absorptive surface area of the gut consistently achieve substantial weight loss, typically 20-35%, effect resolution of co-morbid conditions and improve quality of life. Although mortality is low, complications and hospitalisation are not uncommon after bariatric surgery. Intriguingly, surgical patients experience a reduction in appetite and report changes in food preference. Accentuation of the normal gastrointestinal hormonal response to food intake and possible changes in vagal afferent signalling are proposed to induce satiety. Increased understanding of body weight homeostasis and appetite regulation has provided an impressive list of potential targets for drug development, with the promise that single or combination therapy may ultimately challenge the supremacy of bariatric surgery.

Topics: Adipose Tissue; Amyloid; Anticonvulsants; Antidepressive Agents; Anxiety; Appetite Regulation; Bariatric Surgery; Body Mass Index; Bupropion; Cholecystokinin; Ciliary Neurotrophic Factor; Clinical Trials as Topic; Cyclobutanes; Depression; Diabetes Mellitus, Type 2; Female; Fluoxetine; Fructose; Ghrelin; Humans; Intra-Abdominal Fat; Islet Amyloid Polypeptide; Isoxazoles; Lactones; Leptin; Metabolic Syndrome; Metformin; Obesity; Obesity, Morbid; Orlistat; Oxyntomodulin; Peptide YY; Piperidines; Polycystic Ovary Syndrome; Pyrazoles; Rimonabant; Sertraline; Sleep Apnea, Obstructive; Surgical Procedures, Operative; Topiramate; Zonisamide

Obesity is a chronic metabolic disorder that affects one third of American adults. Modest weight losses of just 5% to 10% of body weight, which are achievable with lifestyle modification and pharmacotherapy, can lead to remarkable improvements in many obesity-associated co-morbidities, including dyslipidemia, hypertension, and type 2 diabetes. In this review, the indications for pharmacotherapy and the goals of treatment are discussed, and current and future pharmacologic approaches to the treatment of obesity are examined. Current pharmacologic therapies for obesity are limited, but recent advances in our understanding of the complex and overlapping endocrine pathways that regulate body weight have led to new opportunities for antiobesity drug development. Important drug targets that are highlighted in this review include adipocyte-derived hormones, hypothalamic neuropeptides, and gastrointestinal hormones.

Topics: Amyloid; Anti-Obesity Agents; Appetite Depressants; Body Weight; Chronic Disease; Comorbidity; Cyclobutanes; Exenatide; Gastrointestinal Hormones; Humans; Islet Amyloid Polypeptide; Lactones; Leptin; Metformin; Obesity; Orlistat; Peptides; Piperidines; Pyrazoles; Randomized Controlled Trials as Topic; Rimonabant; Venoms

Carol McLoughlin looks at the advantages and drawbacks of using drugs to treat obesity and describes new areas of research that may offer new solutions to tackling this rapidly growing health and medical problem.

Topics: Anti-Obesity Agents; Appetite Depressants; Cyclobutanes; Humans; Lactones; Leptin; Obesity; Orlistat

Many experts consider obesity a chronic disease that may require long-term therapy. A loss of 5-15% of body weight is associated with improvements in cardiovascular risk factors and morbidity. However, most studies show that the majority of patients who lose weight relapse. Patients may be unable to maintain a low energy intake when confronted with an almost limitless supply of food. Moreover, a number of physiological mechanisms favour a set point for body weight, that may be altered with anti-obesity drugs.. In the current paper we describe actions and effects of current anti-obesity drugs. The centrally acting drug, sibutramine, is an adrenaline and serotonine re-uptake inhibitor which was recently approved in the USA for obesity. The USA, the European Union and Norway have approved orlistat, a pancreatic lipase inhibitor for weight reduction for up to two years. Patients must maintain a low fat intake in order to avoid gastrointestinal discomfort. In recent studies, orlistat and diet reduced body weight by 9% versus 6% on placebo and diet. No studies have documented long-term safety of anti-obesity drugs.. Treatment of a lifestyle-related disease like obesity with medications is controversial, however, such treatment may not differ substantially from treatment of type II diabetes, hyperlipidaemia or hypertension.

Topics: Anti-Obesity Agents; Appetite Depressants; Cyclobutanes; Fenfluramine; Humans; Lactones; Leptin; Obesity; Obesity, Morbid; Orlistat; Phentermine; Selective Serotonin Reuptake Inhibitors; Weight Loss

Topics: Animals; Appetite Depressants; Cyclobutanes; Humans; Leptin; Mice; Mice, Obese; Obesity; Weight Loss

There is accumulating evidence to support the hypothesis that a low-energy-output phenotype is at high risk of weight gain and obesity, irrespective of whether this is owing to a low resting metabolic rate and/or physical inactivity. The low-energy-output phenotype is associated with impaired appetite control, which is improved if energy output is increased. This is the background for pharmacologic stimulation of energy expenditure as a tool to improve the results of obesity management. Targets are the leptin receptors, the sympathetic nervous system and its peripheral beta-adrenoceptors, selective thyroid hormone derivatives, and stimulation of the mitochondrial uncoupling proteins. Currently available compounds such as recombinant leptin, ephedrine/caffeine, and sibutramine possess thermogenic properties owing to their activation of the sympathoadrenal system. Compounds acting selectively on the human beta3-adrenoceptor are still promising tools to achieve a sustained stimulation of lipolysis and energy expenditure, and several are in the pipeline.

Topics: Adrenal Glands; Anti-Obesity Agents; Caffeine; Cyclobutanes; Energy Metabolism; Ephedrine; Humans; Leptin; Obesity; Recombinant Proteins; Sympathetic Nervous System; Thermogenesis

Obesity is increasing at an alarming rate. During the past decade, the overall prevalence of obesity in the United States increased over 30%, with more than one third of the adult population meeting the definition of being overweight.. We review current and emerging therapies, present outcome data from a large clinical practice, and discuss challenges for physicians and researchers involved in obesity treatment.. Because obesity is a risk factor for numerous medical disorders and excess mortality, it is imperative that effective treatments be developed. While the current conservative therapies produce short-term weight losses, they are ineffective in the long term. Some obesity treatments are controversial, most notably the increasing use of anorexiant medications. For example, the Food and Drug Administration (FDA) recently requested the withdrawal of two widely used medications because of concerns about side effects. Currently, therapies that combine psychosocial interventions, drugs, and extended maintenance appear to have the most promising long-term benefits.. Long-term treatment, including extended pharmacotherapy, may be necessary for many obese patients. Broader definitions of treatment outcome and success, including improvements in comorbid conditions, physical activity, and quality of life are needed.

Topics: 1-Naphthylamine; Adrenergic beta-Agonists; Appetite Depressants; Behavior Therapy; Caffeine; Cyclobutanes; Diethylpropion; Ephedrine; Fenfluramine; Fluoxetine; Humans; Lactones; Leptin; Lipase; Obesity; Orlistat; Phentermine; Proteins; Sertraline

To evaluate the effect of sibutramine on weight loss in obese adolescents.. A double-blind controlled study lasting 13 months. The study included 73 obese adolescents of both sexes aged between 10 and 18 years. Laboratory tests and imaging studies were performed before, during wash-out, and at the end of 13 months.. The percentage of patients who lost 10% of their initial weight in the placebo group was 46%, and in the sibutramine group was 75%. When placebo was used, average weight rose by 1.61 kg, and BMI decreased by 0.24 kg/m(2) whereas with the use of sibutramine, weight decreased by 4.47 kg, and average BMI decreased, 2.38 kg/m(2), with p < 0.001.. Sibutramine induced significantly more weight loss in obese adolescents compared with placebo, without significant side effects. The weight loss curve was different depending on the moment sibutramine was introduced. This finding indicates that the best time to start sibutramine is when adhesion begins to fail.

Topics: Adolescent; Appetite Depressants; Blood Glucose; Body Mass Index; Child; Cholesterol; Cross-Over Studies; Cyclobutanes; Double-Blind Method; Female; Humans; Insulin; Leptin; Male; Patient Safety; Pediatric Obesity; Treatment Outcome; Triglycerides; Weight Loss

The aim of the study was to evaluate the effects of 12-month treatment with sibutramine plus L-carnitine compared with sibutramine alone on body weight, glycemic control, insulin resistance, and inflammatory state in type 2 diabetes mellitus patients. Two hundred fifty-four patients with uncontrolled type 2 diabetes mellitus (glycated hemoglobin [HbA(1c)] >8.0%) in therapy with different oral hypoglycemic agents or insulin were enrolled in this study and randomized to take sibutramine 10 mg plus L-carnitine 2 g or sibutramine 10 mg in monotherapy. We evaluated at baseline and after 3, 6, 9, and 12 months these parameters: body weight, body mass index, HbA(1c), fasting plasma glucose, postprandial plasma glucose, fasting plasma insulin, homeostasis model assessment of insulin resistance index, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, leptin, tumor necrosis factor-α, adiponectin, vaspin, and high-sensitivity C-reactive protein. Sibutramine plus L-carnitine gave a faster improvement of fasting plasma glucose, postprandial plasma glucose, lipid profile, leptin, tumor necrosis factor-α, and high-sensitivity C-reactive protein compared with sibutramine alone. Furthermore, there was a better improvement of body weight, HbA(1c), fasting plasma insulin, homeostasis model assessment of insulin resistance index, vaspin, and adiponectin with sibutramine plus L-carnitine compared with sibutramine alone. Sibutramine plus L-carnitine gave a better and faster improvement of all the analyzed parameters compared with sibutramine alone without giving any severe adverse effect.

Topics: Aged; Appetite Depressants; Blood Glucose; Body Weight; C-Reactive Protein; Carnitine; Cholesterol; Cyclobutanes; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glycated Hemoglobin; Humans; Insulin Resistance; Leptin; Longitudinal Studies; Male; Middle Aged; Tumor Necrosis Factor-alpha; Vitamin B Complex

The efficacy of sibutramine has been demonstrated in randomized trials in obese/overweight patients including those with type 2 diabetes mellitus (T2DM). Our objective was to evaluate the effects of 1-year treatment with sibutramine compared to placebo on body weight, glycaemic control, lipid profile, and inflammatory parameters in type 2 diabetic patients.. Two hundred and forty-six patients with uncontrolled T2DM [glycated haemoglobin (HbA(1c) ) > 8·0%] in therapy with different oral hypoglycaemic agents or insulin were randomized to take 10 mg of sibutramine or placebo for 12 months. We evaluated at baseline, and after 3, 6, 9, and 12 months these parameters: body weight, body mass index (BMI), HbA(1c) , fasting plasma glucose (FPG), post-prandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance index (HOMA-IR), total cholesterol (TC), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), triglycerides (Tg), leptin, tumour necrosis factor-α (TNF-α), adiponectin (ADN), vaspin, high sensitivity C-reactive protein (Hs-CRP).. We observed a decrease of body weight after 9 and 12 months in the group treated with sibutramine, but not in the control group. Regarding glycaemic and lipid profile, although there are differences seen over time within each of the groups, we did not obtain any significant differences between the two groups. Both placebo and sibutramine gave a similar improvement of HOMA-IR, leptin, TNF-α, ADN, and Hs-CRP. No vaspin variations were observed in either group.. Sibutramine resulted in a decrease in body weight at 9 months and at 12 months that was not observed with placebo. Although there were differences seen over time within each of the groups, there were no significant differences between groups for any other parameter that we measured.

Topics: Adiponectin; Appetite Depressants; Blood Glucose; Body Mass Index; Body Weight; C-Reactive Protein; Comorbidity; Cyclobutanes; Diabetes Mellitus, Type 2; Double-Blind Method; Drug Therapy, Combination; Female; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Inflammation; Insulin; Insulin Resistance; Leptin; Lipids; Male; Middle Aged; Obesity; Placebos; Randomized Controlled Trials as Topic; Thiazolidinediones; Time Factors

Sibutramine and metformin are drugs commonly used to obtain weight loss. We aimed to compare the effects of sibutramine alone with that of sibutramine plus metformin combination on weight loss, insulin sensitivity, leptin and C reactive protein in obese women. Seventy obese women were included. After a diet period of month (baseline), each individual was randomly assigned to receive 15 mg sibutramine (sibutramine group; n = 36) or 15 mg sibutramine plus 1,700 mg metformin per day (sibutramine plus metformin group; n = 34) during the next 12 months. Body weight, insulin resistance by the homeostasis model assessment model (HOMA-IR), leptin and C reactive protein were measured at baseline, after 3 months and after 12 months. Mean weight losses in sibutramine and sibutramine plus metformin groups were 5.3 +/- 4.0% (P < 0.001) and 6.8 +/- 3.9% (P < 0.001) after 3 months, and 10.5 +/- 4.4% (P < 0.001) and 15.7 +/- 4.6% (P = 0.007) after 12 months, respectively. HOMA-IR value also decreased in both sibutramine (P = 0.045 and P = 0.002) and sibutramine plus metformin groups (P = 0.04 and P = 0.015) after 3 and 12 months, respectively. Similarly, serum leptin levels decreased in both sibutramine (P = 0.04, P = 0.01) and sibutramine plus metformin groups (P = 0.023, P = 0.025) after 3 and 12 months, respectively. There was also significant reductions in serum C reactive protein levels in both sibutramine (P = 0.045, P = 0.02) and sibutramine plus metformin groups (P = 0.007, P = 0.001) after 3 and 12 months, respectively. These decrements of body weight, HOMA-IR, serum leptin and C reactive protein levels were not statistical significance between these two groups both after 3 and 12 months (P > 0.05). Combination of sibutramine with metformin did not result in any further effects on weight loss, insulin resistance, leptin and C reactive protein levels when compared to sibutramine alone.

Topics: Adult; Appetite Depressants; C-Reactive Protein; Cyclobutanes; Drug Therapy, Combination; Female; Humans; Insulin Resistance; Leptin; Metformin; Middle Aged; Obesity; Treatment Outcome; Weight Loss

Obese patients have high plasma leptin concentrations that do not induce the expected responses on weight regulation, suggesting a leptin resistance in obesity. Elevated leptin levels are also thought to be related to a high sympathetic nervous system (SNS) activity. This effect could be preserved, lowered, or even abolished in obesity. We planned to investigate the possible association in a longitudinal study. Ninety-five normotensive healthy women, aged 40.4 +/- 11.4 years and body mass index of 33.2 +/- 2.3 kg/m(2), were studied. Baseline leptin, fat mass, and heart rate variability were measured and included in a 6-month longitudinal study. Body composition was measured by dual-energy x-ray absorption. Time domain heart rate variability, QT dynamicity, and spectral components on ambulatory electrocardiographs were analyzed. Dietary advice was given by a dietitian to the patient (maximum caloric reduction of 30%), and subjects were randomized in 3 treatment groups: sibutramine 10 mg, sibutramine 20 mg, or placebo. At baseline, low frequencies (LF) and the LF-high frequencies (HF) ratio, mainly related to the SNS, were negatively correlated to leptin concentration (r = -0.30, P = .002 and r = -0.36, P < .001) and to the leptin-fat mass ratio (r = -0.28, P = .004 and r = - 0.33, P = .0007), thus explaining 38% of the LF variance and 33% of the LF/HF variance. Diastolic blood pressure was also negatively correlated to leptin concentrations (-0.20, P = .04) and to the leptin-fat mass ratio (-0.22, P = .022). In contrast, no consistent correlations between leptin and the time domain components related to vagal activity were observed. At 6 months, after completion of the weight loss program, LF significantly decreased (-7.7% +/- 7.9%, P < .001), whereas HF was higher than the initial value (+20% +/- 5.2%). The leptin-fat mass ratio remained negatively correlated to the LF (r = -0.34, P = .030) and to LF/HF (r = -0.35, P = .021) values, explaining 21% of the LF variation. None of the pairwise comparisons between the 2 sibutramine groups and the placebo group were statistically significant for heart rate variability. High leptin concentration is associated with low indexes of cardiac SNS activity and with a lower diastolic blood pressure in normotensive obese women. Our results imply therefore that the relationship between leptin and the autonomic nervous system is disturbed in normotensive obese subjects.

Topics: Adult; Appetite Depressants; Blood Pressure; Body Composition; Cyclobutanes; Female; Heart Rate; Humans; Leptin; Middle Aged; Obesity; Regression Analysis; Sympathetic Nervous System; Weight Loss

The objective of this study is to assess the effects of sibutramine on body weight, body fat distribution, insulin resistance, plasma leptin, lipid profile and blood pressure profiles in hypertensive obese patients.. Eighty-six central obese hypertensive patients (BMI = 39 +/- 5 kg/m(2), 84% of women, 48 +/- 8.5 years old) were placed on a hypocaloric diet and placebo therapy for 4 weeks. They were then randomized to receive sibutramine (10 mg) or placebo for 24 weeks. Both, before therapy and at the end of the study, the waist and hip circumferences were measured and the waist/hip ratio (WHR) was calculated; abdominal ultrasonography was performed in order to estimate the amount of subcutaneous fat (SF) and visceral fat (VF), and the visceral/subcutaneous ratio. Beyond HOMA-r, another insulin resistance index (IRIp) was calculated by means of the formula: peak of blood glucose after oral glucose load x plasma insulin level/10(4). Fasting plasma leptin and lipid levels were also determined.. Sibutramine induced greater weight reduction than placebo (6.7 vs. 2.5%, p < 0.001). Reductions in WHR (0.97 +/- 0.08 vs. 0.94 +/- 0.07, p < 0.01), IRIp (0.11 +/- 0.07 vs. 0.09 +/- 0.06 mmol mu/l(2)) and VF (6.4 +/- 2.4-6.0 +/- 2.4 cm, p < 0.01) were observed only with sibutramine. Plasma leptin decreased with placebo (24 +/- 15 vs. 18 +/- 10 UI/l, p < 0.01), but not with sibutramine (18.8 +/- 8.4 vs. 18.2 +/- 13.2 UI/l). No clinically significant change in lipid profile was observed in both groups. Moreover, office and 24-h blood pressure values did not change during placebo or sibutramine therapy, whereas a significant increase in office heart rate, from 78.3 +/- 7.3-82 +/- 7.9 b.p.m., p = 0.02, was observed with sibutramine.. Sibutramine therapy induced greater body weight loss than placebo in hypertensive obese patients. This was associated with WHR reduction, decreases in VF and insulin resistance. The maintenance of leptin levels during sibutramine therapy may be important to avoid weight recovery, although this finding must be confirmed by other prospective studies.

Topics: Adult; Antihypertensive Agents; Appetite Depressants; Chi-Square Distribution; Cyclobutanes; Drug Therapy, Combination; Female; Glucose Tolerance Test; Humans; Hypertension; Insulin Resistance; Leptin; Lipids; Male; Middle Aged; Obesity; Waist-Hip Ratio; Weight Loss

Some neuropeptides and monoaminergic neurotransmitters may affect hypothalamic feeding centres, sympathetic activity and thermogenesis. Sibutramine (BTS54524; N-[1-[1(4-chloro phenyl) cyclobutyl]-3methyl N,N-dimethylamine hydrochloride monohydrate) is a new 5-HT serotonin and noradrenaline reuptake inhibitor (SNRI), antiobesity drug. The aim of this study was to evaluate the effects of the sibutramine therapy on plasma neuropeptide Y (NPY), insulin, leptin and beta-endorphin concentrations in obese patients.. Sibutramine, serotonin and noradrenaline reuptake antiobesity drug was administered for 6 months in a dose of 10 mg daily in 60 obese women (BMI 30-40 kg/m2) (mean 34 kg/m2). Plasma NPY, leptin, beta-endorphin and insulin concentrations were measured with RIA methods using commercial kits (Peninsula Lab, Linco, Peninsula Lab, Swierk respectively). The above neuropeptides levels were evaluated before and after the 6 month sibutramine therapy in 60 obese women as well as in 30 obese women on low caloric diet and in 30 of the control group.. In 85% obese patients a decrease of body weight was found after 6 month therapy with sibutramine. A decrease in total cholesterol, LDL and triglycerides and an increase in HDL were observed after the sibutramine treatment. We have demonstrated that the sibutramine therapy leads to the decrease of plasma NPY, beta-endorphin, insulin and leptin concentrations in obese patients. After low diet therapy we have observed a decrease in plasma leptin levels, however we did not find significant changes in plasma leptin, NPY, beta-endorphin and insulin concentrations.. We suggest that the effects on the disturbed activity of NPY, beta-endorphin, insulin and leptin may be involved in the mechanism of sibutramine action.

Topics: Adolescent; Adrenergic Uptake Inhibitors; Adult; Analysis of Variance; Appetite Depressants; Appetite Regulation; beta-Endorphin; Cyclobutanes; Female; Humans; Insulin; Leptin; Neuropeptide Y; Obesity; Reference Values; Selective Serotonin Reuptake Inhibitors; Statistics, Nonparametric

Weight reduction on its own is observed to cause improvement in some of the abnormalities seen in patients with polycystic ovary syndrome (PCOS). With respect to this observation, we studied the possible effects of different serotonin reuptake inhibitors (fluoxetine and sibutramine) on serum leptin levels that might play a role in the obesity component seen in patients with PCOS. In a random design, sixteen patients were assigned to fluoxetine and sibutramine for a period of 10 days. In both treatment groups, no significant differences were observed between pre-treatment and post-treatment values in insulin levels (p > 0.05). There was no significant difference between pretreatment and post-treatment serum leptin levels in the fluoxetine treatment group (p > 0.05). However, a significant reduction was observed in the serum leptin levels at the end of treatment in the sibutramine group (p < 0.05). The observed difference in the serum leptin response to the treatment effect of sibutramine compared to fluoxetine seems to be due to a mechanism independent of serotonin reuptake inhibition, possibly to the thermogenic effect of the sibutramine itself. Further studies with larger groups are warranted, to examine the mechanism of the weight-reducing effect of sibutramine. Detailed analyses of basal metabolic activity and change in serum leptin levels should be carried out.

Topics: Adult; Appetite Depressants; Body Mass Index; Cyclobutanes; Female; Fluoxetine; Follicle Stimulating Hormone; Glucose Tolerance Test; Humans; Leptin; Luteinizing Hormone; Polycystic Ovary Syndrome; Selective Serotonin Reuptake Inhibitors

To assess the relationship between serum leptin and insulin resistance (IR) in obesity, and to investigate the effects of sibutramine on obesity, serum leptin and IR.. Seventy obese subjects [body mass index (BMI) > or =25 kg/m2] were randomly divided into 2 groups: group B (sibutramine 10 mg/day) and group C (a placebo tablet/day). Both had been treated for 12 weeks. Another 30 healthy adults served as the normal control (group A: BMI < 23 kg/m2). Their height, body weight, waist and hip circumference, fasting plasms glucose (FPG), fasting plasma insulin (FINS), and serum leptin were examined at the baseline and 12 weeks after the therapy. Insulin senstivity index (ISI) was calculated [ISI = 1/(FPG x FINS)]. Multiple linear regression analysis and partial correlation were performed on serum leptin.. The body weight, BMI, waist and hip circumference decreased significantly after the 12 week-treatment with sibutramine in group B (P < 0.01), but those indexes did not change after the treatment with placebo in group C (P > 0.05). The levels of leptin and FINS were higher (P < 0.01), but ISI was lower (P < 0.01) both in group B and C compared with those in group A at the baseline. The levels of serum leptin and FINS decreased (P < 0.01), and ISI increased significantly (P < 0.05) after the treatment with sibutramine in group B, while those indexes did not change after the treatment with placebo in group C. The most important factors to influence serum leptin level were listed as follows: sex > BMI > FINS > ISI (R2 = 0.661, F = 12.662, P < 0.01). The lep- tin was positively correlated with FINS (r = 0.597, P < 0.01) , but negatively correlated with ISI (r = -0.468, P < 0.01 ) after eliminating the effects of sex and BMI. Conclusion Leptin resistance and insulin resistance exist in obesity, and serum leptin is associated with IR. Treatment with sibutramine significantly reduces the body weight and leptin, increases insulin senstivity, and improves IR.

Topics: Adolescent; Adult; Appetite Depressants; Body Mass Index; Cyclobutanes; Double-Blind Method; Female; Humans; Insulin Resistance; Leptin; Linear Models; Male; Middle Aged; Obesity

The aim of this study was to evaluate the effects of sibutramine on plasma leptin levels, body weight and glucose metabolism in non-dieting women. Fourteen healthy, non-diabetic, obese women were studied before treatment, after 1 week of placebo administration, and after a 2-week course of sibutramine (10 mg/day). At each of these stages, we assessed body composition, measured the levels of plasma leptin, C-peptide and various biochemical parameters, and also recorded plasma insulin and glucose levels during oral glucose tolerance tests. After 1 week of placebo treatment, there were no significant changes in any of the parameters. However, two weeks of 10 mg/day sibutramine dropped plasma leptin levels from a mean (+/-SE) of 48.84+/-4.54 to 42.84+/-4.74 ng/ml (p<0.04), reduced BMI from 39.36+/-2.01 to 38.57+/-1.93 kg/m2 (p<0.002), and decreased insulin resistance (IR, as measured using the homeostasis model assessment of insulin resistance) from 5.59+/-0.85 to 3.66+/-0.43 (p<0.02). There was no correlation between the reduction in leptin concentration and the decrease in BMI, fat mass, percent body fat, IR, C-peptide, or the area under curve for glucose or insulin. There was also no correlation between the decrease in leptin levels and the increases that occurred in the insulin sensitivity index or the hepatic sensitivity index. The results showed that treatment with 10 mg/day sibutramine significantly reduces BMI, IR and leptin levels in non-dieting obese women.

Topics: Adult; Appetite Depressants; Blood Glucose; Body Mass Index; C-Peptide; Cyclobutanes; Female; Glucose Tolerance Test; Homeostasis; Humans; Insulin; Insulin Resistance; Leptin; Liver; Obesity; Placebos

The aim of the present study was to evaluate the cerebrospinal fluid (CSF)/serum leptin ratio during pharmacological therapy for obesity with centrally and peripherally acting drugs. Thirty-one obese women (mean age, 32.3 +/- 10 yr; body mass index, 38.2 +/- 5.2 kg/m(2); body fat, 43.3 +/- 5.4%) were studied before and 2 months after a weight loss program consisting of a balanced diet (1200 kcal/d) plus drug therapy. The patients were randomly assigned into three study groups: group I, fenproporex 25 mg/d (n = 10); group II, sibutramine 10 mg/d (n = 10); and group III, orlistat 120 mg tid (n = 11). Body fat, measured by dual-energy x-ray absorptiometry, and serum and CSF concentrations of leptin were examined at baseline and 2 months after therapy. At baseline, clinical and biochemical characteristics of the groups were similar. All of the women lost weight, approximately 7.0% of their initial body weight, and the reduction was not different among the groups. Serum leptin fell significantly after 2 months in all groups, and the decline was proportional to the reduction in body fat, because leptin levels adjusted for body fat did not change after treatment. CSF leptin levels showed a significant decrease after 2 months in all groups, and this decline was higher on group III compared with group I (P = 0.006). After therapy, the CSF/serum leptin ratio did not change in group I (1.57 +/- 0.3 to 1.72 +/- 0.62%) and group II (1.78 +/- 1.01 to 1.69 +/- 1.27%), whereas it declined significantly in group III (1.65 +/- 0.43 to 1.09 +/- 0.47%; P < 0.01), corresponding to a decrease of 33.3 +/- 22.5% for the CSF/serum leptin ratio. The percentage change in group III was significantly different from the positive variation on group I (11.9 +/- 42.1%; P = 0.006) and close to the statistical significance compared with the negative variation seen in group II (-7.6 +/- 27.8%; P = 0.06). Our results showed that the CSF/serum leptin ratio decreased after weight loss in obese women treated during 2 months with orlistat, whereas this ratio did not change in this period of time in obese women treated with fenproporex and sibutramine.

Topics: Adolescent; Adult; Amphetamines; Anti-Obesity Agents; Appetite Depressants; Cyclobutanes; Humans; Lactones; Leptin; Middle Aged; Obesity; Orlistat; Weight Loss

The relation between insulin-leptin-visceral fat axis during weight loss has not been studied previously.. To evaluate the insulin, leptin, and abdominal adiposity relation during weight loss in patients with upper body obesity.. Twenty volunteers (7 men, 13 women) with mean age 50.6+/-6.3 (SD) and upper body obesity (weight 105.4+/-12.3 kg, BMI 35.9+/-2.5 kg/m2) were recruited. Participants were enrolled in a one-arm clinical study using a calorie-deficient diet and an escalating dose regimen of sibutramine, starting with 5 mg daily and increasing in 5-mg increments to 20 mg per day. Body weight, insulin, leptin, glucose, lipids, abdominal computed tomography (CT), and total body electrical conductance (TOBEC) were measured serially at weeks 0, 4, 8, 12, and 24.. Eighteen patients completed the 6-month study: one man and one woman discontinued because of adverse events. With diet and sibutramine, body weight was significantly and continuously reduced throughout the 6-month study. There was a 16.0% (p = 0.0001) reduction in body weight (p < 0.001) and 22.5% (p = 0.0001) decrease in total body fat mass. Abdominal CT scans showed a 28.3% (p = 0.0001) reduction in total abdominal fat, a 26.0% (p = 0.0001) reduction in subcutaneous fat (p < 0.001), and a 31.0% (p = 0.0003) reduction in visceral fat (p < 0.001). There was a 32.0% (p = 0.0008) reduction in leptin levels and 37.9% (p = 0.0001) reduction in insulin levels between baseline and week 4, but no further significant reduction in leptin and insulin levels was observed for the duration of the study. There was a significant correlation between insulin and leptin concentrations throughout the study (p = 0.0001). Leptin was presented as a function of insulin measured at the same time. Significant associations between visceral abdominal fat, subcutaneous fat, and leptin were also observed.. In this study, we found that leptin and insulin were related in weight loss. The data suggest that insulin may act as a strong regulator of leptin secretion during weight loss and that circulating leptin levels can be predicted by insulin level. Using sibutramine in conjunction with hypocaloric diet reduced body weight and decreased fat mass significantly. Visceral and subcutaneous abdominal fat depots were shown to decrease. Whether sibutramine exerts any selective reduction of visceral abdominal fat as opposed to total body fat mass will require further clinical investigation.

Topics: Adipose Tissue; Adult; Appetite Depressants; Cyclobutanes; Diet, Reducing; Female; Humans; Insulin; Leptin; Male; Middle Aged; Obesity; Time Factors; Viscera; Weight Loss

Sibutramine is an anti-obesity agent that induces weight loss by selective inhibition of neuronal reuptake of serotonin and norepinephrine; however, it is associated with the risk of cardiovascular diseases (CVD), including heart attack and stroke. Here, we analyzed global protein expression patterns in plasma of control and sibutramine-treated rats using proteomic analysis for a better understanding of the two conflicting functions of this drug, appetite regulation, and cardiovascular risk. The control (n=6) and sibutramine-treated groups (n=6) were injected by vehicle and sibutramine, respectively, and 2-DE combined with MALDI-TOF/MS were performed. Compared to control rats, sibutramine-administered rats gained approximately 18% less body weight and consumed about 13% less food. Plasma leptin and insulin levels also showed a significant decrease in sibutramine-treated rats. As a result of proteomic analysis, 23 differentially regulated proteins were discovered and were reconfirmed by immunoblot analysis. Changed proteins were classified into appetite regulation and cardiovascular risk, according to their regulation pattern. Because the differential levels of proteins that have been well recognized as predictors of CVD risk were not well matched with the results of our proteomic analysis, this study does not conclusively prove that sibutramine has an effect on CVD risk.

Topics: Adipose Tissue; Animals; Appetite Depressants; Appetite Regulation; Blood Proteins; Body Weight; Cardiovascular Diseases; Chromatography, Liquid; Cyclobutanes; Electrophoresis, Gel, Two-Dimensional; Insulin; Leptin; Male; Obesity; Proteome; Rats; Rats, Sprague-Dawley; Risk Factors; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Weight Loss

Topiramate is newly approved as anticonvulsant that seems to promote body weight loss in humans. The present study was designed to evaluate the weight-controlling properties of topiramate in dietary obese female rats in comparison with sibutramine.. Fifty rats were assigned as normal, high fat diet (HFD), HFD + sibutramine (7.5 mg/kg, p.o.), HFD + topiramate (25 mg/kg, p.o.) and HFD + topiramate (50 mg/kg, p.o.). Body weight was registered, anxiety was tested in Vogel's test and blood pressure (BP) was measured. In addition, liver index, adipose tissue index, fasting blood glucose and serum lipid profile were measured in all groups. Further, serum insulin, leptin and adiponectin were determined.. Feeding with HFD induced a significant increase in body weight of rats as well as insulin resistance and serum lipids as compared to normal group (p<0.05). These measurements were suppressed by sibutramine treatment. However, a significant elevation in BP and anxiety behavior were detected as compared with HFD group (p<0.05). Topiramate (50 mg/kg, p.o.) group showed weight loss, improved insulin resistance, lessened anxiety behavior without influence on BP.. Our data ensures the findings that topiramate has a weight controlling properties with no anxiogenic or hypertensive effects. Further investigations are needed to determine the utility of topiramate in the clinical management of obesity.

Topics: Animals; Anti-Obesity Agents; Blood Glucose; Blood Pressure; Cyclobutanes; Female; Fructose; Insulin; Insulin Resistance; Leptin; Lipids; Obesity; Rats; Topiramate; Weight Loss

The availability of useful animal models reflecting the human obesity syndrome is crucial in the search for novel compounds for the pharmacological treatment of obesity. In the current study, we have performed an extensive characterization of the obesity syndrome in a polygenetic animal model, namely the selectively bred diet-induced obese (DIO) and diet-resistant (DR) rat strains. We show that they constitute useful models of the human obesity syndrome. DIO and DR rats were fed either a high-energy (HE) or a standard chow (Chow) diet from weaning to 9 months of age. Metabolic characterization including blood biochemistry and glucose homeostasis was examined at 2, 3, 6, and 9 months of age. Furthermore, in 6-month-old HE-fed DIO rats, the anti-obesity effects of liraglutide and sibutramine were examined in a 28-day study. Only HE-fed DIO rats developed visceral obesity, hyperleptinemia, hyperinsulinemia, and dyslipidemia, and showed a worsening of glucose tolerance over time. In line with the hyperlipidemic profile, a severe hepatic fat infiltration was observed in DIO rats at 6 months of age. The effects of liraglutide and sibutramine were tested in 6-month-old DIO rats. Both compounds effectively reduced food intake and body weight in DIO rats. Liraglutide furthermore improved glucose tolerance when compared with sibutramine. Our data highlights the usefulness of a polygenetic animal model for screening of compounds affecting food intake, body weight, and glucose homeostasis. Furthermore, the results underscore the effectiveness of GLP-1 mimetics both as anti-diabetes and anti-obesity agents.

Topics: Analysis of Variance; Animals; Appetite Depressants; Blood Glucose; Cyclobutanes; Diet; Disease Models, Animal; Eating; Enzyme-Linked Immunosorbent Assay; Feeding Behavior; Glucagon-Like Peptide 1; Insulin; Insulin Resistance; Leptin; Liraglutide; Metabolic Syndrome; Obesity; Rats; Rats, Sprague-Dawley

The aim of the study was to investigate: a) the differential effect of the three main macronutrients on food intake, fat depots and serum leptin levels and b) the impact of sibutramine on the above parameters in rats fed ad libitum with three isocaloric diets.. Three groups of male Wistar rats (n = 63) were fed with a high fat diet (HFD), a high carbohydrate diet (HCD) or a high protein diet (HPD) for 13 weeks. In the last three weeks, each group was divided into three subgroups and received sibutramine (S) either at 5 mg/kg or 10 mg/kg, or vehicle. Food intake was measured daily during the last week of the experiment; perirenal and epididymal fat and fat/lean ratio were calculated and serum leptin was assayed.. HFD-fed rats demonstrated elevated food intake and higher regional fat depots. S at 10 mg/kg decreased food intake in the HFD and epididymal fat in the HCD group. S also reduced perirenal fat in the HCD and HPD groups. Leptin levels were higher in rats fed with either the HFD or the HPD compared to those fed with the HCD. Moreover, S at 10 mg/kg decreased serum leptin levels in the HPD group.. Results suggest a preferential effect of S on perirenal visceral fat and support the view that body fat loss is greater when its administration is accompanied by a HCD diet. No effect of S on leptin levels was found, besides that expected as a result of the decrease in body fat.

Topics: Adipose Tissue; Animals; Appetite Depressants; Cyclobutanes; Diet; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Eating; Leptin; Lipid Metabolism; Male; Rats; Rats, Wistar; Time Factors

To further address the function of the Y5 receptor in energy homeostasis, we investigated the effects of a novel spironolactone Y5 antagonist in diet-induced obese (DIO) mice.. Male C57BL/6 or Npy5r(-/-) mice were adapted to high-fat (HF) diet for 6-10 months and were submitted to three experimental treatments. First, the Y5 antagonist at a dose of 10 or 30 mg/kg was administered for 1 month to DIO C57BL/6 or Npy5r(-/-) mice. Second, the Y5 antagonist at 30 mg/kg was administered for 1.5 months to DIO C57BL/6 mice, and insulin sensitivity was evaluated using an insulin tolerance test. After a recovery period, nuclear magnetic resonance measurement was performed to evaluate body composition. Third, DIO mice were treated with the Y5 antagonist alone, or in combination with 10% food restriction, or with another anorectic agent, sibutramine at 10 mg/kg, for 1.5 months. Plasma glucose, insulin, and leptin levels, and adipose tissue weights were quantified.. The spironolactone Y5 antagonist significantly reduced body weight in C57BL DIO mice, but not in Npy5r(-/-) DIO mice. The Y5 antagonist produced a fat-selective loss of body weight, and ameliorated obesity-associated insulin resistance in DIO mice. In addition, the Y5 antagonist combined with either food restriction or sibutramine tended to produce greater body weight loss, as compared with single treatment.. These findings demonstrate that the Y5 receptor is an important mediator of energy homeostasis in rodents.

Topics: Adiposity; Animals; Anti-Obesity Agents; Appetite Depressants; Blood Glucose; Body Weight; Caloric Restriction; Combined Modality Therapy; Cyclobutanes; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Therapy, Combination; Eating; Insulin; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Receptors, Neuropeptide Y; Spiro Compounds; Spironolactone; Time Factors

The high prevalence of obesity and cardiovascular risk factors in hypopituitarism affirms the need for effective weight loss intervention. In this study, we investigated the combined effect of sibutramine, diet, and exercise in obese hypopituitary patients (HPs).. In an open-label prospective intervention trial, 14 obese well-substituted nondiabetic HPs and 14 matched simple obese controls were allocated to 11-month treatment with sibutramine (10 to 15 mg), diet (600 kcal/d deficit), and exercise. Anthropometric indices and body composition (obtained from DXA scan) were assessed monthly for the first 5 months and thereafter every second month for the next 6 months.. Mean (+/-SD) weight loss at 11 months was 11.3 +/- 4.8 kg in patients vs. 10.7 +/- 4.7 kg in controls. The HPs exhibited the same improvements in body composition, waist circumference, blood lipids, and fasting glucose as the simple obese. In a multivariate model, baseline weight, duration of growth hormone replacement therapy, and duration of pituitary disease explained 79% (p = 0.001) of the variation in weight loss at 4 months in the HPs. Only baseline weight and waist circumference could predict weight loss at 11 months.. HPs are not resistant to weight loss therapy. Almost all will achieve at least 5% weight loss, and 60% can lose >10% weight within 11 months. However, the long-term effect on risk factors associated with type 2 diabetes and cardiovascular disease as well as on mortality needs to be established.

Topics: Adult; Anthropometry; Appetite Depressants; Blood Glucose; Body Composition; Cholesterol; Combined Modality Therapy; Cyclobutanes; Exercise; Female; Human Growth Hormone; Humans; Hypopituitarism; Leptin; Lipids; Male; Middle Aged; Obesity; Pregnancy; Weight Loss

Topics: Agouti-Related Protein; alpha-MSH; Animals; Anti-Obesity Agents; Appetite; Arcuate Nucleus of Hypothalamus; Ciliary Neurotrophic Factor; Clinical Trials as Topic; Cyclobutanes; Energy Intake; Ghrelin; Humans; Hunger; Intercellular Signaling Peptides and Proteins; Lactones; Leptin; Mice; Nerve Tissue Proteins; Neurons; Neuropeptide Y; Obesity; Orlistat; Peptide Fragments; Peptide Hormones; Peptide YY; Phentermine; Proteins; Receptors, Corticotropin; Receptors, Melanocortin; Weight Loss

Topics: Anti-Obesity Agents; Appetite Depressants; Body Mass Index; Counseling; Cyclobutanes; Diet, Reducing; Drug Therapy, Combination; Exercise; Female; Humans; Lactones; Leptin; Life Style; Obesity; Orlistat; Patient Education as Topic; Patient Selection; Primary Health Care; United States; Weight Loss; Women's Health

We studied the effects of the novel noradrenaline and serotonin (5-HT) reuptake inhibitor sibutramine on feeding and body weight in a rat model of dietary obesity, and whether it interacts with hypothalamic neuropeptide Y (NPY) neurones. Chow-fed and dietary-obese (DIO) male Wistar rats were given sibutramine (3 mg kg(-1) day(-1) p.o.) or deionized water for 21 days. Sibutramine decreased food intake throughout the treatment period in both dietary-obese rats (P<0.0001) and lean rats (P<0.0001). Weight gain was reduced so that final body weight was 10% lower in dietary-obese (P<0.005) and 8% lower in lean (P<0.05) rats versus their untreated controls. Plasma leptin concentration was lower in sibutramine-treated dietary-obese rats (P<0.05), and in treated lean rats (P<0.05). Using the homeostasis model assessment (HOMA) as a measure of insulin resistance, untreated DIO rats were significantly more insulin resistant than controls (P<0.005), and this was corrected by sibutramine treatment (P<0.05). Neither hypothalamic NPY mRNA nor NPY peptide levels in a number of hypothalamic nuclei were significantly altered by sibutramine compared to untreated controls. The hypophagic and anti-obesity effects of sibutramine in dietary-obese Wistar rats appear not to be mediated by inhibition of ARC NPY neurones.

Topics: Adipose Tissue; Animals; Appetite Depressants; Body Weight; Cyclobutanes; Diet; Feeding Behavior; Hypothalamus; Insulin Resistance; Leptin; Male; Neurons; Neuropeptide Y; Obesity; Rats; Rats, Wistar; RNA, Messenger

Tachyphylaxis to the effects of anorexigenic agents, such as sibutramine (S), may be due, in part, to counterregulatory decreases in energy expenditure (EE) and increases in hunger that result from reduced circulating leptin (L) due to loss of body fat and lowered L production/adipocyte. The present study was conducted to test the hypothesis that L administered at low doses sufficient to restore ambient L to preweight loss concentrations would enhance the intercurrent efficacy of S by reducing the strength of physiologic counterregulation to weight loss. Forty male Sprague-Dawley rats were fed a high-fat (HF) diet (45% energy) to induce obesity. After 8 weeks, the obese rats (600 +/- 58 g) were weight-matched into 4 groups (N = 8/group) and implanted subcutaneously (SC) with 2 mL, 7-day Alzet mini-pumps that provided: vehicle (V, saline), L (0.5 mg/kg/d), S (3 mg/kg/d), or L+S. Food intake (FI) on the HF diet was measured daily. On day 7, 24-hour EE was measured by indirect calorimetry, and the animals then killed for body composition analysis. Compared with vehicle, treatment with S alone, but not L alone, produced significant weight loss (-23 +/- 26 v -6 +/- 16 g, P <.01). L alone, or with S, increased fat oxidation (decreased respiratory quotient [RQ]) compared with V (P <.05). The lack of decline in EE with S may be due to its documented effect to stimulate thermogenesis. Administration of L with S synergistically decreased FI and increased weight loss and fractional fat loss. A reduction in plasma L concentration may contribute to the "plateau phenomenon" observed in studies of weight loss therapies. Replacement doses of L during S administration increased weight loss and fractional fat loss by (1) decreasing food intake and (2) by increasing fat oxidation. Such drug combinations may be useful in the treatment of human obesity.

Topics: Animals; Body Composition; Body Weight; Cyclobutanes; Diet; Drug Synergism; Energy Intake; Energy Metabolism; Feeding Behavior; Leptin; Male; Obesity; Rats; Rats, Sprague-Dawley

Chronic administration of sibutramine lowers body weight, presumably by altering brain monoamine metabolism. Here the effect of sibutramine on sympathoadrenal function (24-h urine norepinephrine and epinephrine levels) and arcuate nucleus (ARC) neuropeptide Y (NPY) and proopiomelanocortin (POMC) expression was assessed in diet-induced obese rats fed a low-fat diet. Chronic (10 wk) sibutramine [5 mg. kg(-1). day(-1) ip; rats fed ad libitum and injected with sibutramine (AS)] lowered body weight by 15% but only transiently (3-4 wk) reduced intake compared with vehicle-treated controls [rats fed chow ad libitum and injected with vehicle daily (AV)]. Other rats food restricted (RS) to 90% of the weight of AS rats and then given sibutramine restored their body weights to the level of AS rats when allowed libitum food intake. After reequilibration, RS rats were again energy restricted to reduce their weight to 90% of AS rats, and additional vehicle-treated rats (RV) were restricted to keep their body weights at the level of AS rats for 3 wk more. Terminally, total adipose depot weights and leptin levels paralleled body weights (AV > AS = RV > RS), although AS rats had heavier abdominal and lighter peripheral depots than RV rats of comparable body weights. Sibutramine treatment increased sympathetic activity, attenuated the increased ARC NPY, and decreased POMC mRNA levels induced by energy restriction in RV rats. Thus sibutramine lowered the defended body weight in association with compensatory changes in those central pathways involved in energy homeostasis.

Topics: Adipose Tissue; Animals; Appetite Depressants; Arcuate Nucleus of Hypothalamus; Body Weight; Cyclobutanes; Energy Intake; Epinephrine; Feeding Behavior; Gene Expression Regulation; Homeostasis; Leptin; Neuropeptide Y; Norepinephrine; Obesity; Organ Size; Pro-Opiomelanocortin; Rats; RNA, Messenger

This paper reviews recent developments and findings regarding the role of the hypothalamus as the main site in the central nervous system (CNS) for regulating appetite. It contains a specific neural network consisting of the main central monoaminergic neurotransmitters (adrenaline, noradrenaline, dopamine, serotonin) and many neuropeptides with orexigenic and anorexigenic functions. The crucial relationship between CNS and obesity and the complex interconnections of CNS and peripheral peptides are becoming clearer. The mechanisms by which these hormones affect energy homeostasis through long and short-term anabolic and catabolic pathways are described. New anti-obesity therapeutic strategies based on drugs or molecules with new mechanisms of action, some not yet available in Italy but will soon be on the market, are considered.

Topics: Appetite Depressants; Body Weight; Brain; Cyclobutanes; Energy Intake; Homeostasis; Humans; Leptin; Obesity

Topics: Appetite Depressants; Behavior Therapy; Cyclobutanes; Diet, Reducing; Disease Outbreaks; Female; Global Health; Humans; Leptin; Norepinephrine; Obesity; Prevalence; Proteins