Behavioural treatment of the overweight patient

Robust Reductions of Body Weight and Food Intake by an Oxytocin Analog in Rats

Background: Oxytocin is a hypothalamic neuropeptide that participates in the network of appetite regulation. Recently the oxytocin signaling pathway has emerged as an attractive target for treating obesity. However, the short half-life limits its development as a clinical therapeutic. Here we provide results from testing a long-lasting, potent and selective oxytocin analog ASK1476 on its efficacy to reduce food intake and body weight in comparison to the native oxytocin peptide.

Methods: ASK1476 features two specific amino acid substitutions in positions 7 and 8 combined with a short polyethylene glycol spacer. Short time dose escalation experiments testing increasing doses of 3 days each were performed in diet-induced overweight (DIO) male rats assessing effects on body weight as well as changes in food intake. Furthermore, DIO rats were tested for changes in body weight, food intake, temperature, and locomotor activity over 28 days of treatment (oxytocin, ASK1476, or vehicle).

Results: In dose escalation experiments, significant reductions in food intake relative to baseline were detected beginning with doses of 15 nmol/kg ASK1476 (−15.2 ± 2.3 kcal/d, p = 0.0017) and 20 nmol/kg oxytocin (−11.2.9 ± 2.4 kcal/d, p = 0.0106) with corresponding significant changes in body weight (ASK1476: −5.2 ± 0.8 g, p = 0.0016; oxytocin: −2.6 ± 0.7 g, p = 0.0326). In long-term experiments, there was no difference on body weight change between 120 nmol/kg/d ASK1476 (−71.4 ± 34.2 g, p = 0.039) and 600 nmol/kg/d oxytocin (−91.8 ± 32.2 g, p = 0.035) relative to vehicle (706.9 ± 28.3 g), indicating a stronger dose response for ASK1476. Likewise, both ASK1476 and oxytocin at these doses resulted in similar reductions in 28-day cumulative food intake (ASK1476: −562.7 ± 115.0 kcal, p = 0.0001; oxytocin: −557.1 ± 101.3 kcal, p = 0.0001) relative to vehicle treatment (2716 ± 75.4 kcal), while no effects were detected on locomotor activity or body temperature.

Conclusion: This study provides proof-of-concept data demonstrating an oxytocin analog with extended in vivo stability and improved potency to reduce food intake and body weight in DIO animals which could mark a new avenue in anti-obesity drug interventions.

A randomized clinical trial of the effectiveness of a Web-based health behaviour change support system and group lifestyle counselling on body weight loss in overweight and obese subjects: 2-year outcomes

BACKGROUND

Weight loss can prevent and treat obesity-related diseases. However, lost weight is usually regained, returning to the initial or even higher levels in the long term. New counselling methods for maintaining lifestyle changes are urgently needed.

OBJECTIVES

An information and communication technology-based health behaviour change support system (HBCSS) that utilizes persuasive design and methods of cognitive behavioural therapy (CBT) was developed with the aim of helping individuals to maintain body weight. The purpose of this study was to assess whether CBT-based group counselling combined with HBCSS or HBCSS alone helps to maintain improved lifestyle changes needed for weight loss compared to self-help guidance or usual care.

METHODS

A randomized lifestyle intervention for overweight or obese persons (BMI 27-35 kg m^-2 and age 20-60 years), recruited from the population registry in the city of Oulu, Finland, was conducted. This study comprised six randomly assigned study arms: CBT-based group counselling (eight sessions led by a nutritionist), self-help guidance-based group counselling (SHG; two sessions led by a nurse) and control, each with or without HCBSS, for 52 weeks. Subjects visited the study centre for anthropometric measurements, blood sample collection and to complete questionnaires at baseline, 12 and 24 months. The main outcome was weight change from baseline to 12 months and from baseline to 24 months.

RESULTS

Of the 1065 volunteers screened for the study, 532 subjects (51% men) met the inclusion criteria and were enrolled. The retention rate was 80% at 12 months and 70% at 24 months. CBT-based counselling with HBCSS produced the largest weight reduction without any significant weight gain during follow-up. The mean weight change in this arm was 4.1% [95% confidence interval (CI), -5.4 to -2.8, P < 0.001) at 12 months and 3.4% (95% CI, -4.8 to -2.0, P < 0.001) at 24 months. HBCSS even without any group counselling reduced the mean weight by 1.6% (95% CI, -2.9 to -0.3, P = 0.015) at 24 months.

CONCLUSION

The combination of CBT-based group counselling and HBCSS-based weight management is feasible for overweight or obese individuals. Moreover, HBCSS alone could be disseminated to the population at large as an effective means of treating obesity.

The Role of Bariatric Surgery in the Obese Total Joint Arthroplasty Patient

Although bariatric surgery is a proven means of weight loss and treatment of obesity-related comorbidities in morbidly obese patients, it is not yet clear how it affects outcomes after total joint arthroplasty in this high-risk patient population. This article explores the effects of obesity and bariatric surgery on osteoarthritis and total joint arthroplasty, and also discusses the financial and ethical implications of use of bariatric surgery for risk reduction before total joint arthroplasty.

A novel multidisciplinary intervention for long-term weight loss and glycaemic control in obese patients with diabetes

INTRODUCTION

Obesity and diabetes are difficult to treat in public clinics. We sought to determine the effectiveness of the Metabolic Rehabilitation Program (MRP) in achieving long-term weight loss and improving glycaemic control versus "best practice" diabetes clinic (DC) in obese patients using a retrospective cohort study.

METHODS

Patients with diabetes and BMI > 30 kg/m(2) who attended the MRP, which consisted of supervised exercise and intense allied health integration, or the DC were selected. Primary outcomes were improvements in weight and glycaemia with secondary outcomes of improvements in blood pressure and lipid profile at 12 and 30 months.

RESULTS

Baseline characteristics of both cohorts (40 MRP and 40 DC patients) were similar at baseline other than age (63 in MRP versus 68 years in DC, P = 0.002). At 12 months, MRP patients lost 7.65 ± 1.74 kg versus 1.76 ± 2.60 kg in the DC group (P < 0.0001) and 9.70 ± 2.13 kg versus 0.98 ± 2.65 kg at 30 months (P < 0.0001). Similarly, MRP patients had significant absolute reductions in %HbA1c at 30 months versus the DC group (-0.86 ± 0.31% versus 0.12% ± 0.33%, P < 0.038), with nonsignificant improvements in lipids and blood pressure in MRP patients.

CONCLUSION

Further research is needed to establish the MRP as an effective strategy for achieving sustained weight loss and improving glycaemic control in obese patients with type 2 diabetes.

Comparative effectiveness of plant-based diets for weight loss: a randomized controlled trial of five different diets

OBJECTIVE

The aim of this study was to determine the effect of plant-based diets on weight loss.

METHODS

Participants were enrolled in a 6-mo, five-arm, randomized controlled trial in 2013 in South Carolina. Participants attended weekly group meetings, with the exception of the omnivorous group, which served as the control and attended monthly meetings augmented with weekly e-mail lessons. All groups attended monthly meetings for the last 4 mo of the study. Diets did not emphasize caloric restriction.

RESULTS

Overweight adults (body mass index 25-49.9 kg/m(2); age 18-65 y, 19% non-white, and 27% men) were randomized to a low-fat, low-glycemic index diet: vegan (n = 12), vegetarian (n = 13), pesco-vegetarian (n = 13), semi-vegetarian (n = 13), or omnivorous (n = 12). Fifty (79%) participants completed the study. In intention-to-treat analysis, the linear trend for weight loss across the five groups was significant at both 2 (P < 0.01) and 6 mo (P < 0.01). At 6 mo, the weight loss in the vegan group (-7.5% ± 4.5%) was significantly different from the omnivorous (-3.1% ± 3.6%; P = 0.03), semi-vegetarian (-3.2% ± 3.8%; P = 0.03), and pesco-vegetarian (-3.2% ± 3.4%; P = 0.03) groups. Vegan participants decreased their fat and saturated fat more than the pesco-vegetarian, semi-vegetarian, and omnivorous groups at both 2 and 6 mo (P < 0.05).

CONCLUSIONS

Vegan diets may result in greater weight loss than more modest recommendations.

Long-term weight loss maintenance and management following a VLCD: a 3-year outcome

BACKGROUND

Effective weight loss treatment is important as obesity has severe health and socioeconomic repercussions. Emerging evidence suggests that rapid initial weight loss results in better long-term weight loss maintenance. This remains controversial and contradicts current recommendations for slower weight loss.

AIM

To determine the effect of a very low calorie diet (VLCD) with group-based behaviour therapy on weight loss and long-term weight management by means of a retrospective database analysis.

METHODS

Data for this retrospective analysis included participants who embarked on the LighterLife Total VLCD programme between 2007 and 2010, and whose weights at baseline and at least 12 months were available (n = 5965).

RESULTS

Data were available for 5965 individuals at 1 year, 2044 at 2 years and 580 at 3 years. At baseline, the majority of individuals were Caucasian (n = 5155), female (n = 5419), ≥ 40 years old (n = 4272), 49% were within the body mass index (BMI) range of 30-35 kg/m(2) while 51% had a BMI > 35 kg/m(2) . The average initial weight of the whole cohort was 99.1 kg (SD 16.6). Initial weight and BMI at entry onto programme, as well as numbers of weeks of weight loss were all significantly associated with weight loss achieved on the first weight loss attempt. Weight lost during the initial weight loss phase was the only factor, which was significantly associated with percentage weight loss maintenance for years 1, 2, and 3.

CONCLUSION

The findings of this retrospective analysis suggest that provided a longer term weight loss management programme is adhered to, large amounts of initial weight loss can result in important longer term weight loss maintenance in motivated individuals.

Obesity and symptomatic osteoarthritis of the knee

Given the growing prevalence of obesity around the world and its association with osteoarthritis of the knee, orthopaedic surgeons need to be familiar with the management of the obese patient with degenerative knee pain. The precise mechanism by which obesity leads to osteoarthritis remains unknown, but is likely to be due to a combination of mechanical, humoral and genetic factors. Weight loss has clear medical benefits for the obese patient and seems to be a logical way of relieving joint pain associated with degenerative arthritis. There are a variety of ways in which this may be done including diet and exercise, and treatment with drugs and bariatric surgery. Whether substantial weight loss can delay or even reverse the symptoms associated with osteoarthritis remains to be seen. Surgery for osteoarthritis in the obese patient can be technically more challenging and carries a risk of additional complications. Substantial weight loss before undertaking total knee replacement is advisable. More prospective studies that evaluate the effect of significant weight loss on the evolution of symptomatic osteoarthritis of the knee are needed so that orthopaedic surgeons can treat this patient group appropriately.

Evaluating Parents and Adult Caregivers as “Agents of Change” for Treating Obese Children: Evidence for Parent Behavior Change Strategies and Research Gaps

This scientific statement addresses parents and adult caregivers (PACs) as “agents of change” for obese children, evaluating the strength of evidence that particular parenting strategies can leverage behavior change and reduce positive energy balance in obese youth. The statement has 3 specific aims. The first is to review core behavior change strategies for PACs as used in family-based treatment programs and to provide a resource list. The second is to evaluate the strength of evidence that greater parental “involvement” in treatment is associated with better reductions in child overweight. The third is to identify research gaps and new opportunities for the field. This review yielded limited and inconsistent evidence from randomized controlled clinical trials that greater PAC involvement necessarily is associated with better child outcomes. For example, only 17% of the intervention studies reported differential improvements in child overweight as a function of parental involvement in treatment. On the other hand, greater parental adherence with core behavior change strategies predicted better child weight outcomes after 2 and 5 years in some studies. Thus, the literature lacks conclusive evidence that one particular parenting strategy or approach causally is superior to others in which children have a greater focus in treatment. A number of research gaps were identified, including the assessment of refined parenting phenotypes, cultural tailoring of interventions, examination of family relationships, and incorporation of new technologies. A conceptual model is proposed to stimulate research identifying the determinants of PAC feeding and physical activity parenting practices, the results of which may inform new treatments. The statement addresses the need for innovative research to advance the scope and potency of PAC treatments for childhood obesity.

Postoperative complication rates in the "super-obese" hip and knee arthroplasty population

The effect of obesity on the outcomes of total joint arthroplasties is an ongoing concern. As obesity becomes more endemic, new categories emerge, such as the "super-obese." We conducted a retrospective study to determine the difference in outcomes among the super-obese. When categorized according to body mass index (BMI), the overall rate of complications was higher for patients with BMI of 45 or higher. Super-obese patients had an odds ratio (OR) of 8.44 for developing inhospital complications. Most importantly, each incremental 5-U increase in BMI above 45 was associated with an increased risk of inhospital (OR, 1.69) and outpatient complications (OR, 2.71), and readmission (OR, 2.0), compared with patients with BMI of 45 to 50. Length of stay was increased by 13.8% for each 5-U increase in BMI above 45. There is a significant increased risk for complications in the super-obese population, and this continues to increase with BMI increases above 45. These data are important when counseling super-obese patients and should be accounted for in reporting quality outcome measures in this population.

The impact of pre-operative obesity on weight change and outcome in total knee replacement

We carried out a prospective, continuous study on 529 patients who underwent primary total knee replacement between January 2006 and December 2007 at a major teaching hospital. The aim was to investigate weight change and the functional and clinical outcome in non-obese and obese groups at 12 months post-operatively. The patients were grouped according to their pre-operative body mass index (BMI) as follows: non-obese (BMI < 30 kg/m2), obese (BMI 3 30 to 39 kg/m2) and morbidly obese (BMI > 40 kg/m2). The clinical outcome data were available for all patients and functional outcome data for 521 (98.5%). Overall, 318 (60.1%) of the patients were obese or morbidly obese.

At 12 months, a clinically significant weight loss of ≥ 5% had occurred in 40 (12.6%) of the obese patients, but 107 (21%) gained weight. The change in the International Knee Society score was less in obese and morbidly obese compared with non-obese patients (p = 0.016). Adverse events occurred in 30 (14.2%) of the non-obese, 59 (22.6%) of the obese and 20 (35.1%) of the morbidly obese patients (p = 0.001).

Weight-loss maintenance 1, 2 and 5 years after successful completion of a weight-loss programme

The objective was to assess weight-loss maintenance in individuals who successfully completed a commercial weight-loss programme at multiple sites in the United States. A total of 699 lifetime members of Weight Watchers represented the national sample and 217 additional lifetime members served as an oversample. Lifetime members were asked to self-report their current weight 1, 2, and 5 years after they had successfully completed the programme. Additional lifetime members served as an oversample whose weights were measured. The discrepancy between reported and measured weight in the oversample was used to adjust the self-reported weights of the national sample. Seventy-one percent of participants were middle-aged or older and 95.3 % were female; their mean starting BMI was 27.6 (sd 3.6) kg/m2. The percentage of Weight Watchers lifetime members who maintained at least 5 % of their weight loss 1, 2 and 5 years after successful completion of the programme was 79.8, 71.0, and 50.0, respectively. The percentage of participants who remained below their goal weight 1, 2 and 5 years after completion of the programme was 26.5, 20.5, and 16.2, respectively. Results obtained with this group of successful Weight Watchers members are not directly comparable to those obtained with clinical samples of obese dieters because the current sample comprises only the most successful Weight Watchers participants. However, these results provide further evidence that maintenance of weight loss in those who successfully lose weight in one commercial weight-loss programme is more feasible than data from clinical populations have suggested.

Tratamiento psicológico de la obesidad

Obesity is a chronic disease. Current management is based in the modification of the lifestyle, mainly regarding to eating habits and physical activity. Eating habits are acquired during the childhood and kept through the entire life. Modification of any habit requires the use of specific psychological methods such as cognitive-behavioural therapy, which is based on first notions of learning theories. Very often, obese patients and therapist think that the obesity is a problem not related to other aspects of their lives. Thus the objective of the treatment is only weight loss, instead of looking for a modification of patient's behaviour. In the present review we try to update the treatment of obesity in adult patients mainly regarding to the psychological approach.

GRB14, GPD1, and GDF8 as potential network collaborators in weight loss-induced improvements in insulin action in human skeletal muscle

Obesity is associated with insulin resistance in skeletal muscle; accordingly, weight loss dramatically improves insulin action. We sought to identify molecular remodeling of muscle commensurate with weight loss that could explain improvements in insulin action. Muscle from morbidly obese women was studied before and after gastric bypass surgery. Gastric bypass surgery significantly reduced body mass by approximately 45% and improved insulin action. We then assessed mRNA profiles using a stringent statistical analysis (statistical concordance with three probe set algorithms), with validation in a cross-sectional study of lean (n = 8) vs. morbidly obese (n = 8) muscle. Growth factor receptor-bound protein 14 (GRB14), glycerol-3-phosphate dehydrogenase 1 (GPD1), and growth differentiation factor 8 (GDF8; myostatin) significantly decreased approximately 2.4-, 2.2-, and 2.4-fold, respectively, after weight loss (gastric bypass). Increased expression of these transcripts was associated with increased obesity in the cross-sectional group (lean vs. morbidly obese muscle). Each transcript was validated by real-time quantitative RT-PCR assays in both study groups. Using Ingenuity Pathway Analysis, we show that all three transcripts are involved in the same regulatory network including AKT1, IGF1, TNF, PPARG, and INS. These results suggest that GRB14, GPD1, and GDF8 are weight loss-responsive genes in skeletal muscle and that the observed transcriptional modulation of these would be expected to improve insulin signaling, decrease triglyceride synthesis, and increase muscle mass, respectively, with weight loss. Thus our data provide a possible regulatory pathway involved in the development of insulin resistance in the morbidly obese state, and improvement of insulin resistance with weight loss.

Conservative treatment of obesity in an academic obesity unit. Long-term outcome and drop-out

OBJECTIVE

The aim of this study was to explore the outcome and the problems of drop-out in the treatment of obese outpatients at an academic obesity unit.

DESIGN

A two-year clinical treatment evaluation.

SUBJECTS

A total of 117 obese subjects, 83 women and 34 men, mean aged 50 (23-70) years, with an average body mass index (BMI) of 39.0 kg/m2 (28.8- 64.7).

INTERVENTION

All treatment was based on group therapy and included behaviour modification and nutrition counselling. A team of nurses, dieticians, a physiotherapist, a psychotherapist and a physician supervised the treatment. Two programmes were used. Group 1 initially received a low-calorie diet (LCD) for seven weeks combined with the behaviour treatment programme. Group 2 was treated with the behaviour treatment programme only. All subjects were offered complementary treatment according to their medical needs.

RESULTS

There was a continuous drop-out of subjects during the two-year treatment period with an overall drop-out rate of 53%. Anthropometric characteristics, medical history or reasons for drop-out had no impact on the drop-out rate. In completers the weight reduction after two years was 9.2 [+/-10.8 standard deviation (S.D.) kg. In non-completers the weight reduction of the last observed weight measurement was 4.7 (+/-7.9 S.D.) kg. After year two, the weight reduction in Group 1 was 8.8 (+/-12.2 S.D.) kg, and in Group 2 was 9.7 (+/-8.0 S.D.) kg.

CONCLUSION

This study has showed the difficulties of long-term clinical treatment of obese outpatients, even in a specialised obesity clinic. The findings demonstrate that educated and experienced staff together with an extended package of treatment options is not enough to keep patients in treatment for two years. However though the drop-out rate was high, two thirds of the included subjects reduced their weight, which is a satisfactory result in a clinical setting. The drop-out rate and the reasons for dropping out could give a clue in which direction the diagnostics and analysis of the subject's individual needs in health care should be directed.

Clinical Implications of Obesity With Specific Focus on Cardiovascular Disease

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

Practical Office Strategies for Weight Management of the Obese Diabetic Individual

SUMMARY

Obesity is a key component of the insulin-resistance syndrome of type 2 diabetes, and intensifies comorbidities underlying the increased cardiovascular risk of individuals with type 2 diabetes. Weight loss leads to dramatic beneficial effects, with reductions in blood glucose levels and improvements in lipid profiles and blood pressure that often necessitate reductions in medications. Successful long-term weight loss is difficult to achieve in patients with diabetes, as standard dietary approaches often have minimal long-term impact, and intensive management strategies designed to improve glycemic control often contribute to further weight gain in these patients. This article offers a review of newer strategies for enhancing lifestyle change and weight loss in the obese diabetic individual. Use of meal replacements provides structure with portion control, and increased intake of fruits and vegetables promotes a healthier eating style for these patients. Encouraging physical activity such as walking, stair climbing, and gardening can significantly improve cardiorespiratory fitness and glycemic control, and helps patients maintain weight loss. Self-monitoring through lifestyle diaries can reinforce the healthy behaviors necessary for long-term management of obesity. Adjunctive antiobesity medication, medically-supervised intensive weight loss programs, and minimally invasive gastric bypass procedures are important options for patients unable to make significant progress with behavioral changes.

Structured weight-loss programs: meta-analysis of weight loss at 24 weeks and assessment of effects of intervention intensity

Obesity is increasing in epidemic proportions globally while current therapies continue to be suboptimal. In this investigation, weight loss in obese individuals after 24 weeks with different nutrition interventions was compared. The impact of intervention intensity was assessed. Inclusion criteria were established and a comprehensive literature review was performed. These nutrition interventions were identified and analyzable: meal replacements (MRs); energy-restricted (>1500 kcal/d) diets (ERDs); low-energy (800-1500 kcal/d) diets (LEDs); soy very low energy (<800 kcal/d) diets (VLEDs) referred to as SOYs; and VLEDs. Intensity was assessed using the following parameters: physician visits, clinic visits, and hours of class over 24 weeks; an intensity score represents an adjusted sum of the values. Weight losses at 24 weeks as percentage of baseline weights (95%, confidence intervals) were as follows: MRs, 9.1% (5.7-12.5); ERDs, 8.5% (4.9-12.1); LEDs, 11.4% (8.9-13.1); SOYs, 16.5% (13.9-19.1); and VLEDs, 21.3% (20.1-22.5). Weight loss with SOYs was significantly greater than with MRs and ERDs; weight loss with VLEDs was significantly greater than with any other diet. Energy intake was the most significant (P<.0001) regression variable related to weight loss; however, the intensity of intervention (P=.0003) was significantly stronger than initial body weight or duration of treatment. Medically supervised VLEDs are the most effective intervention for facilitating substantial weight loss over 24 weeks. SOY may promote more rapid weight loss over the first 8 weeks than other interventions. MRs appear to be equally effective with ERDs and LEDs with lower levels of intervention intensity.

Interest of pronostic score for optimal clinical management of obese patients

OBJECTIVE

The aim of this retrospective study was to identify key factors favoring weight regain.

METHODS

Therefore, prognostic factors for weight loss and regain have been retrieved and identified among 186 obese patients (40 +/- 2 y and 34 +/- 0.3 kg/m(2)) through the use of a simple questionnaire which considered psychological issues such as depression, anxiety and the patient's individual capacity to follow a diet. All patients have been prescribed a low-calorie diet (1200 kcal/day) being either balanced, food-combining or low-CHO. Follow-up averaged 6.4 +/- 0.3 months of which weight loss accounted for 4.4 +/- 0.1 months.

RESULTS

Weight loss was similar in all 3 groups and averaged 6.0 +/- 0.2 kg. The final weight loss and weight regain results have been identical for the 3 groups. A high/bad prognostic score rating is associated with weight regain (P<0.02). Weight regain is significantly influenced by the initial weight loss speed (P<0.0001).

CONCLUSIONS

The proposed prognostic score is likely to be helpful for clinicians better to profile the therapeutic approach to individualized obesity management and follow-up. Diet composition does not influence either weight loss or weight regain.

Medical management of obesity

Obesity has become a major health problem in many countries because of its high prevalence and causal relationship with serious medical complications. Many of the medical complications associated with obesity improve with intentional weight in a dose-dependent fashion, and even a modest weight loss of 50% of initial weight has beneficial effects. This article reviews the nonsurgical approaches for achieving weight loss in obese persons.

Human genomics and obesity: finding appropriate drug targets

The increasing prevalence of obesity worldwide has prompted the World Health Organization (WHO) to classify it as a global epidemic. Around the globe, more than a half billion people are overweight, and the chronic disease of obesity represents a major threat to health care systems in developed and developing countries. The major health hazards associated with obesity are the risks of developing diabetes, cardiovascular disease, stroke, osteoarthritis and some forms of cancer. In this paper, we review the prevalence of obesity and its cost to health care systems and present the relative contribution of environmental conditions and genetic makeup to the development of obesity in people. We also discuss the concept of "essential" obesity in an "obesigenic" environment. Though weight gain results from a sustained imbalance between energy intake and energy expenditure, it is only recently that studies have identified important new mechanisms involved in the regulation of body weight. The etiology of the disease is presented as a feedback model in which afferent signals inform the central controllers in the brain as to the state of the external and internal environment and elicit responses related to the regulation of food intake and energy metabolism. Pharmaceutical agents may intervene at different levels of this feedback model, i.e., reinforce the afferent signals from the periphery, target the central pathways involved in the regulation of food intake and energy expenditure, and increase peripheral energy expenditure and fat oxidation directly. Since obesity results from genetic predisposition, combined with the proactive environmental situation, we discuss new potential targets for generation of drugs that may assist people in gaining control over appetite as well as increasing total energy expenditure and fat oxidation.

Effects of sibutramine plus orlistat in obese women following 1 year of treatment by sibutramine alone: a placebo-controlled trial

OBJECTIVE

This study assessed whether adding orlistat to sibutramine would induce further weight loss in patients who previously had lost weight while taking sibutramine alone.

RESEARCH METHODS AND PROCEDURES

Patients were 34 women with a mean age of 44.1 +/- 10.4 years, weight of 89.4 +/- 13.8 kg, and body mass index (BMI) of 33.9 +/- 4.9 kg/m2 who had lost an average of 11.6 +/- 9.2% of initial weight during the prior 1 year of treatment by sibutramine combined with lifestyle modification. Patients were randomly assigned, in double-blind fashion, to sibutramine plus orlistat or sibutramine plus placebo. In addition to medication, participants were provided five brief lifestyle modification visits during the 16-week continuation trial.

RESULTS

Mean body weight did not change significantly in either treatment condition during the 16 weeks. The addition of orlistat to sibutramine did not induce further weight loss as compared with treatment by sibutramine alone (mean changes = +0.1 +/- 4.1 kg vs. +0.5 +/- 2.1 kg, respectively).

DISCUSSION

These results must be interpreted with caution because of the study's small sample size. The findings, however, suggest that the combination of sibutramine and orlistat is unlikely to have additive effects that will yield mean losses > or =15% of initial weight, as desired by many obese individuals.