Three-month tolerability of orlistat in adolescents with obesity-related comorbid conditions

A meta-analysis of obesity interventions among U.S. minority children

PURPOSE

To quantitatively evaluate the efficacy of interventions designed to prevent or treat obesity among U.S. minority children using meta-analytic techniques.

METHODS

A total of 40 intervention trials involving 10,725 children aged 6-19 years were examined.

RESULTS

Interventions with more components showed a higher mean effect size than those with fewer components: among 32 controlled trials, d = .07 for one-component (n = 6); d = .08 for two-component (n = 15); d = .33 for three-component (n = 10); and d = .71 for four-component (n = 1) interventions. Interventions with parental involvement (n = 22, d = .21) and lifestyle interventions (n = 14, d = .34) showed a greater mean effect size than those without parental involvement (n = 10, d = .05) or lifestyle interventions (n = 18, d = .04), despite the fact that their 90% confidence intervals overlapped. Among uncontrolled trials (n = 8), two-component interventions (n = 5) yielded d = .86 and three-component interventions (n = 3) yielded d = .96.

CONCLUSIONS

Evidence indicates that, among U.S. minority children, obesity interventions with three or more components might be more efficacious than those using fewer components. Parental involvement, lifestyle change, culturally-based adaptation, and interactive computer programs seem to show promise in the reduction of obese minority children.

Energy intake and energy expenditure among children with polymorphisms of the melanocortin-3 receptor

BACKGROUND

Homozygosity for 2 protein-altering polymorphisms in the melanocortin-3 receptor gene (MC3R) coding sequence, C17A and G241A, has been reported to be associated with an obesity phenotype in children, yet how these polymorphisms affect energy homeostasis is unknown. Association between adult body weight and +2138InsCAGACC, another variant in the 3' untranslated region of MC3R, has also been described.

OBJECTIVE

The objective of this study was to examine associations of C17A + G241A and +2138InsCAGACC MC3R variants with children's energy balance.

DESIGN

Children aged 6-19 y were genotyped for MC3R C17A, G241A, and +2138InsCAGACC. Subjects underwent studies of energy intake from a 9835-kcal food array (n = 185), resting energy expenditure (REE) by using indirect calorimetry (n = 302), or total daily energy expenditure (TEE) by using doubly labeled water (n = 120). Linear regression was used to examine the associations between MC3R polymorphisms and the measures of energy balance.

RESULTS

Body mass index and fat mass were greater in those with double homozygosity for C17A + G241A (P = 0.001). After accounting for covariates (including body composition), the number of minor C17A + G241A alleles was associated with significantly greater energy intake (beta = +0.15, P = 0.02) but not altered REE or TEE. No significant associations were observed between +2138InsCAGACC and measures of either fat mass or energy balance.

CONCLUSIONS

C17A + G241A polymorphisms may be associated with pediatric obesity because of greater energy intake rather than because of diminished energy expenditure. +2138InsCAGACC does not appear to be associated with obesity or measures of energy balance in children.

Pharmacotherapy in pediatric obesity: current agents and future directions

Childhood obesity is emerging as a major public health threat, with adverse implications on the health of individuals and long-term costs to society. Family-based lifestyle interventions with behavioral modification, diet and exercise form the mainstay of treatment. Pharmacologic treatment may be considered in selected subjects, especially in the presence of significant and severe comorbidities, when lifestyle intervention has failed to achieve weight reduction. Orlistat and sibutramine are FDA-approved for treatment of pediatric obesity; metformin may be considered in the presence of clinically significant insulin resistance. Evidence is lacking on the appropriate duration of medical therapy and optimal combination with lifestyle intervention. Lack of coverage of medications by insurance and high out-of-pocket costs may be limiting factors to some families. Adverse effects necessitate careful monitoring and may lead to discontinuation of medication. Pharmacologic agents with novel mechanisms of action offer hope of improved efficacy, tolerability and safety.

Disordered-eating attitudes in relation to bone mineral density and markers of bone turnover in overweight adolescents

PURPOSE

To examine the relationships between cognitive eating restraint and both bone mineral density (BMD) and markers of bone turnover in overweight adolescents.

METHODS

One hundred thirty-seven overweight (BMI 39.1 +/- 6.8 kg/m(2)) African American and Caucasian adolescent (age = 14.4 +/- 1.4 years) girls (66.4%) and boys were administered the Eating Disorder Examination (EDE) interview and Eating Inventory (EI) questionnaire and underwent dual energy X-ray absorptiometry (DXA) to measure total lumbar spine BMD. Markers of bone formation (serum bone specific alkaline phosphatase and osteocalcin), bone resorption (24-hour urine N-telopeptides), and stress (urine free cortisol) were measured.

RESULTS

After accounting for the contribution of demographics, height, weight, serum 25-hydroxyvitamin D, and depressive symptoms, adolescents' weight concern, as assessed by interview, was a significant contributor to the model of urine free cortisol (beta = .30, p < .05). Shape concern, as also assessed by interview, was significantly associated with lumbar spine bone mineral density (beta = -.15, p < .05). Dietary restraint was not a significant predictor in any of these models.

CONCLUSIONS

These findings suggest that among severely overweight adolescents, dissatisfaction with shape and weight may be salient stressors. Future research is required to illuminate the relationship between bone health and disordered-eating attitudes in overweight adolescents.

Metabolic syndrome in the pediatric population: a short overview

The metabolic syndrome (MS) in adults is defined as a concurrence of obesity, disturbed glucose and insulin metabolism, hypertension and dyslipidemia, and is associated with increased morbidity and mortality from cardiovascular diseases and type 2 diabetes. Studies now indicate that many of its components are also present in children and adolescents. Moreover, the clustering of these risk factors has been documented in some children, who are at increased cardiovascular risk in adulthood. The MS is highly prevalent among overweight children and adolescents. Identifying these children is important for early prevention and treatment of different components of the syndrome. The first-line treatment comprises lifestyle modification consisting of diet and exercise. The most effective tool for prevention of the MS is to stop the development of childhood obesity. The first attempt at consensus-based pediatric diagnostic criteria was published in 2007 by the International Diabetes Federation. Nevertheless, national prevalence data, based on uniform pediatric definition, protocols for prevention, early recognition and effective treatment of pediatric MS are still needed.The aim of this article is to provide a short overview of the diagnosis and treatment options of childhood MS, as well as to present the relationships between MS and its individual components.

The first decade of sibutramine and orlistat: a reappraisal of their expanding roles in the treatment of obesity and associated conditions

Ancillary therapies for weight management, consisting mainly of diet and exercise programs that incorporate variable levels of lifestyle modification techniques, are frequently ineffective to achieve clinically meaningful weight loss and maintenance. Although pharmacological treatment of obesity is widely used in most countries, the number of available drugs is still very limited. The most widely used anti-obesity agents are sibutramine and orlistat, both available in clinical practice for about a decade. A large number of clinical trials have demonstrated that both agents are safe and well tolerated, with a level of efficacy in the moderate weight loss recommended by the most relevant clinical guidelines. Several studies have assessed the efficacy and safety of sibutramine and orlistat in adolescents and also for the treatment of some associated conditions in adults, including type 2 diabetes, polycystic ovary syndrome and binge eating disorder. The positive results of these studies suggest an expanding role for both agents, not only for the treatment of obesity, but also for associated conditions. After the efficacy of orlistat for the prevention of type 2 diabetes demonstrated in the XENDOS study, the results of SCOUT study are awaited for a better evaluation of sibutramine impact on cardiovascular outcomes.

A review of adolescent obesity: prevalence, etiology, and treatment

Much of adult obesity has its roots in childhood. One of the tragedies of the current obesity epidemic is the significant and increasing prevalence of obesity in the young. One principal predictor of adult obesity is childhood obesity. We describe here the classification, epidemiology, causality, comorbidities, and treatment of adolescent obesity, both pharmacologic and surgical.

An update in prevention and treatment of pediatric obesity

BACKGROUND

Obesity prevalence is growing as well as its severity with increasing morbidity and mortality. This "globesity" also affects developing countries where under nutrition and stunting frequently coexist with overweight and obesity. One third of obese adults began to be so in the pediatric ages. There are two main types of prevention: general one representing greater actions from health authorities and the individual one carried out by the pediatrician and the patient at risk. Once the state of obesity is reached (relative body mass index, rBMI >121%) the longer lasting care becomes more complex and frequently unsuccessful. The treatment of obesity is aimed to care for the present and silent disorders and for preventing its further tracking to adulthood.

DATA SOURCES

Identification of pediatric population at risk which is the one with an rBMI of 111%-120% plus other risk factors. Specific individual actions include reduction of food intake, increase of energy expenditure, involvement of parents, and the child-adolescent himself in the prevention. Therapy is based on some principles plus the important medical and emotional approach.

RESULTS

A Cochrane study based on only 10 appropriate studies showed a predominant poor efficacy of the undergone preventive action. Treatment guides are presented after our own experience with a group of 400 kids with an average follow-up of 7 years and other individual prevention studies.

CONCLUSIONS

Involving motivated pediatricians with a minimum of time for visits and better follow-up in the frame of a general national preventive programme could be a rational outcome. Treatment of obesity should never be postponed whatever the clinical care is.

An overview of obesity in children with psychiatric disorders taking atypical antipsychotics

BACKGROUND

Children with psychiatric illness are at greater risk for obesity than those in the general population. In part, this greater risk is due to the escalating use of psychotropic medications. Second-generation antipsychotics effectively treat mental illness but are associated with weight gain. Data for management of obesity in this population is lacking.

METHODS

Articles on obesity, mental illness, and obesity management were reviewed. Keywords included children, adolescents, obesity, weight gain, psychiatric illness, therapy, treatment, and antipsychotic.

RESULTS

For pediatric obesity, educational, nutritional, behavioral, and family-based interventions were identified as nonpharmacological interventions. All nonpharmacological modalities indicate modest to moderate success in weight control or loss. Pharmacological agents, alone or with diet and exercise, appear promising in obesity management.

CONCLUSION

Since there are limited intervention studies available for obese children with psychiatric illness, general childhood obesity studies may be referenced for trials in this population. Long-term efficacy and safety of these interventions are not yet available. Methodological constraints of prior studies include small sample sizes and the absence of randomized, placebo-controlled, and longitudinal trials - highlighting the need for further trials addressing these issues. Clinical monitoring and management of medication-induced obesity remains an important public health concern.

Structure analysis of the Children's Eating Attitudes Test in overweight and at-risk for overweight children and adolescents

BACKGROUND

In school-based samples of children, the Children's Eating Attitudes Test (ChEAT) has a four-factor structure; however, previous studies have not examined its factor structure in samples restricted to overweight youth.

METHODS

The ChEAT was administered to 220 overweight (BMI>or=95th percentile) and 45 at-risk for overweight (BMI 85th-<95th percentile) children and adolescents. Factors were identified by a principal component analysis with varimax rotation. ChEAT factor scores of children with BMI>or=85th percentile were contrasted with those of 152 non-overweight (BMI 5th to <85th percentile) children and adolescents.

RESULTS

Factor analysis generated four subscales described as 'body/weight concern,' 'food preoccupation,' 'dieting,' and 'eating concern.' ChEAT total score, body/weight concern, and dieting subscale scores were positively related to BMI-Z and body fat mass (p's<.05). Compared to non-overweight children, overweight and at-risk for overweight children had higher ChEAT total (9.9+/-7.4 vs. 6.6+/-7.8, p<.001), body/weight concern (3.2+/-3.1 vs. 1.3+/-3.0, p<.001), and dieting (1.8+/-2.2 vs. .8+/-2.3, p<.001) subscale scores.

CONCLUSIONS

The previously elucidated factor structure of the ChEAT was primarily supported in a sample of overweight children. The emergence of separate body/weight concern and dieting subscales may relate to these children's experiences with attempted weight reduction.

Obesity and carpal tunnel syndrome: is there a causal relationship?

OBJECTIVES

Obesity is defined as a risk factor for carpal tunnel syndrome (CTS). In this study, the presence or absence of recovery in median nerve conduction velocities after weight loss in obese patients was assessed in order to determine whether excess weight or other factors influence the higher prevalence of CTS in obese patients.

METHODS

Patients with body mass indexes (BMIs) >or=30 were included in the study. CTS symptoms, age, gender, height, body weight, and concomitant diseases were evaluated. Nerve conduction studies (NCS) were obtained on one upper extremity. All patients were included in dietetic programs. Three months later, NCS were repeated and compared with the first NCS.

RESULTS

BMIs were statistically significantly lower on the second visits 3 months later (p = 0.0001). No statistically significant difference was observed in the second NCS of electromyographically diagnosed cases with CTS (p > 0.05).

CONCLUSION

We expected a recovery in median nerve conduction velocities in patients with CTS after weight loss. In the literature, even in untreated cases with CTS, spontaneous improvements in second NCS have been reported. This finding suggests that factors other than excess body weight may be influential in the higher prevalence of CTS in obese patients. A more detailed, genetic-factor-targeted investigation may prove more beneficial to clarify this issue.

A multisite investigation of binge eating behaviors in children and adolescents

The phenomenology of childhood and adolescent loss of control (LOC) eating is unknown. The authors interviewed 445 youths to assess aspects of aberrant eating. LOC was associated with eating forbidden food before the episode; eating when not hungry; eating alone; and experiencing secrecy, negative emotions, and a sense of "numbing" while eating (ps<.01). Hierarchical cluster analysis revealed a subgroup, most of whom reported LOC eating. Cluster members reported having a trigger initiate episodes, eating while watching television, and having decreased awareness regarding the amount consumed. The authors conclude that aspects of LOC eating during youth are similar to aspects of adult episodes, but a youth-specific presentation may exist. Findings may provide an intervening point to prevent excessive weight gain and eating disorders.

Treatment of childhood obesity

PURPOSE OF REVIEW

To provide an overview of treatments for childhood obesity, highlighting recent advances and recommendations.

RECENT FINDINGS

The three main treatment modalities are lifestyle interventions, medications, and bariatric surgery. Recent data support the short-term effectiveness of lifestyle interventions, and show that continued behavioral intervention increases the likelihood of a sustained effect for up to 2 years. New studies and regulatory decisions on medications for obesity (including orlistat, sibutramine, and metformin) are discussed. Emerging data suggest substantial weight loss after bariatric surgery in morbidly obese adolescents but also indicate adverse effects. An expert panel recently provided guidelines that alter definitions of obesity and offer a framework for obesity management. These guidelines are compared with others, and integrated recommendations presented.

SUMMARY

While primary prevention of childhood obesity is important, broadly effective methods to do so are not yet available. Given the large population of obese children and the risks they face, an emphasis on treatment is also critical. We suggest a staged approach, emphasizing early intervention and lifestyle changes. We also suggest limiting bariatric surgery to selected adolescents in Institutional Review Board-approved research studies. Health-policy interventions can facilitate both prevention and treatment of childhood obesity.

Recommendations for treatment of child and adolescent overweight and obesity

In this article, we review evidence about the treatment of obesity that may have applications in primary care, community, and tertiary care settings. We examine current information about eating behaviors, physical activity behaviors, and sedentary behaviors that may affect weight in children and adolescents. We also review studies of multidisciplinary behavior-based obesity treatment programs and information about more aggressive forms of treatment. The writing group has drawn from the available evidence to propose a comprehensive 4-step or staged-care approach for weight management that includes the following stages: (1) Prevention Plus; (2) structured weight management; (3) comprehensive multidisciplinary intervention; and (4) tertiary care intervention. We suggest that providers encourage healthy behaviors while using techniques to motivate patients and families, and interventions should be tailored to the individual child and family. Although more intense treatment stages will generally occur outside the typical office setting, offices can implement less intense intervention strategies. We not ony address specific patient behavior goals but also encourage practices to modify office systems to streamline office-based care and to prepare to coordinate with professionals and programs outside the office for more intensive interventions.

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

Background

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

Methods

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

Discussion

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

Conclusion

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

Oxygen-uptake efficiency slope as a determinant of fitness in overweight adolescents

PURPOSE

Peak oxygen uptake (VO2peak) is frequently difficult to assess in overweight individuals; therefore, submaximal measures that predict VO2peak are proposed as substitutes. Oxygen uptake efficiency slope (OUES) has been suggested as a submaximal measurement of cardiorespiratory fitness that is independent of exercise intensity. There are few data examining its value as a predictor of V O2peak in severely overweight adolescents.

METHODS

One hundred seven severely overweight (BMI Z 2.50 +/- 0.34) and 43 nonoverweight (BMI Z 0.13 +/- 0.84) adolescents, performed a maximal cycle ergometer test with respiratory gas-exchange measurements. OUES was calculated through three exercise intensities: lactate inflection point (OUES LI), 150% of lactate inflection point (OUES 150), and VO2peak (OUES PEAK).

RESULTS

When adjusted for lean body mass, VO2peak and OUES at all exercise intensities were lower in overweight subjects (VO2peak: 35.3 +/- 6.4 vs 46.8 +/- 7.9 mL.kg(-1) LBM.min(-1), P < 0.001; OUES LI: 37.9 +/- 10.0 vs 43.7 +/- 9.2 mL.kg(-1) LBM.min(-1).logL(-1) P < 0.001; OUES 150: 41.6 +/- 9.0 vs 49.8 +/- 11.1 mL.kg(-1) LBM.min(-1).logL(-1) P < 0.001; and OUES PEAK: 45.1 +/- 8.7 vs 52.8 +/- 9.6 mL.kg(-1) LBM.min(-1).logL(-1) P < 0.001). There was a significant increase in OUES with increasing exercise intensity in both groups (P < 0.001). OUES at all exercise intensities was a significant predictor of VO2peak for both groups (r2 = 0.35-0.83, P < 0.0001). However, limits of agreement for predicted VO2peak relative to actual VO2peak were wide (+/- 478 to +/- 670 mL.min(-1)).

CONCLUSIONS

OUES differs significantly in overweight and nonoverweight adolescents. The wide interindividual variation and the exercise intensity dependence of OUES preclude its use in clinical practice as a predictor of VO2peak.

Effects of lifestyle intervention and metformin on weight management and markers of metabolic syndrome in obese adolescents

PURPOSE

The purposes of this study are threefold: to determine what components of the metabolic syndrome are present in obese adolescents, to determine what differences exist in the effects of lifestyle intervention versus lifestyle intervention plus metformin on weight management and select markers of metabolic syndrome in obese adolescents, and to determine which factors predict weight loss in obese adolescents treated with lifestyle changes and metformin.

DATA SOURCES

The study was a secondary data analysis utilizing a retrospective chart review of 63 obese adolescents aged 11 through 18 who were treated for obesity at the LeBonheur Youth Lifestyle Clinic from January 1, 2000, through June 30, 2005. Lifestyle interventions included diet, exercise, and counseling. The medication utilized was metformin. Outcomes evaluated included body mass index, relative body mass index (RBMI), weight, waist and hip circumference, blood pressure, serum lipid levels, fasting plasma glucose, 2-h oral glucose tolerance tests, and insulin levels. Changes in mean values between groups were evaluated using the General Linear Models procedure. Logistic regression was utilized to determine which factors might predict weight loss.

CONCLUSIONS

The metformin group (N= 37) tended to be heavier, older, and had more components of the metabolic syndrome than the nonmetformin group (N= 26). All components of the metabolic syndrome were present in both groups (overall prevalence 55%). Both groups had a downward trend in RBMI, a surrogate marker for weight loss, but only the metformin group had a significant loss in RBMI points from baseline to end. There was a trend toward better diastolic blood pressure at 6 months in the metformin group (p= 0.06), which was not seen in the nonmetformin group. The only predictors of weight loss were higher RBMI (those who were heavier lost more) and the absence of type 2 diabetes mellitus (type 2 DM) (those with type 2 DM were less likely to lose 10 or more points in RBMI).

IMPLICATIONS FOR PRACTICE

All components of the metabolic syndrome are present in obese adolescents. The use of lifestyle changes and lifestyle changes plus metformin both produce some degree of weight loss, but subjects on metformin in this study lost significantly more RBMI points than those on lifestyle changes alone. Subjects with type 2 DM are less likely to lose weight than those without type 2 DM. Larger studies and studies with subjects more representative of the general population need to be carried out to assist in the development of evidence-based practice guidelines.

State of the Art Review: Long-term Pharmacotherapy for Overweight and Obesity: A Review of Sibutramine, Orlistat, and Rimonabant

The objective of this review is to evaluate the safety and efficacy of pharmacotherapy for long-term maintenance of weight loss in overweight and obese patients. Literature was obtained through a MEDLINE (1966 to July 2006) search and a bibliographic review of published articles. Key terms used included overweight, obesity, sibutramine, orlistat, and rimonabant. The search was further limited to clinical trials in humans and in the English language. Obesity is a chronic condition requiring long-term therapy. Two agents, sibutramine and orlistat, are currently approved by the Food and Drug Administration for the long-term treatment of obesity. Rimonabant, marketed in Europe as Accomplia, has demonstrated efficacy for long term weight loss, however an Food and Drug Administration advisory panel voted against its approval in June 2007 due to safety concerns (psychiatric effects). For clinically meaningful results, these agents must be used in conjunction with lifestyle therapy, including a hypocaloric diet, increased physical activity, and behavioral modification. This article reviews clinical trials evaluating the safety and efficacy of sibutramine, orlistat, and rimonabant in reducing weight and examines other health benefits and risks associated with these agents.

Pharmacotherapeutic options for overweight adolescents

OBJECTIVE

To evaluate the safety and efficacy of current pharmacotherapeutic options for weight loss in overweight adolescents.

DATA SOURCES

Literature was obtained through MEDLINE Ovid (1996-April 2007) and EMBASE Drugs and Pharmacology (1991-2nd quarter 2007) searches and a bibliographic review of published articles. Key words included adolescents, overweight, obesity, anti-obesity agents, drug therapy, orlistat, sibutramine, and metformin.

STUDY SELECTION AND DATA EXTRACTION

All studies published in the English language that evaluated the use of pharmacotherapy for the treatment of overweight adolescents were critically analyzed; pertinent articles were selected for this review.

DATA SYNTHESIS

Orlistat has been approved for use in adolescents between the ages of 12 and 16 years. The most frequently reported adverse effects of orlistat were gastrointestinal; reduced concentrations of fat-soluble vitamins were also observed. Of the 6 clinical trials published, 5 have shown statistically significant reductions in body mass index (BMI) from baseline, ranging from 0.55 to 4.09 kg/m2; one small trial failed to demonstrate significant weight reduction compared with placebo. Sibutramine has also been evaluated for use in overweight adolescents in 6 trials. Trials demonstrated a statistically significant reduction in BMI up to 5.6 kg/m2 (from baseline). Of concern is evidence indicating that sibutramine therapy may be associated with elevated blood pressure, increased pulse rate, depression, and suicidal ideations. Lastly, metformin has recently been evaluated for weight loss in overweight adolescents; small, short-term trials demonstrate modest reductions in weight and BMI.

CONCLUSIONS

Orlistat has been proven both safe and effective for weight reduction in overweight adolescents. Sibutramine has also been proven effective in reducing weight in this population; however, the potential for severe adverse effects requires further investigation. Metformin has demonstrated promising results in small trials; its role in the treatment of overweight adolescents will remain investigational until further research is conducted.

Screening and treatment for lipid disorders in children and adolescents: systematic evidence review for the US Preventive Services Task Force

OBJECTIVE

This was a systematic evidence review for the US Preventive Services Task Force, intended to synthesize the published evidence regarding the effectiveness of selecting, testing, and managing children and adolescents with dyslipidemia in the course of routine primary care.

METHODS

Literature searches were performed to identify published articles that addressed 10 key questions. The review focused on screening relevant to primary care of children without previously identified dyslipidemias, but included treatment trials of children with dyslipidemia because some drugs have only been tested in that population.

RESULTS

Normal values for lipids for children and adolescents are defined according to population levels (percentiles). Age, gender, and racial differences and temporal trends may alter these statistical cut points. Approximately 40% to 55% of children with elevated total cholesterol and low-density lipoprotein levels will continue to have elevated lipid levels on follow-up. Current screening recommendations based on family history will fail to detect substantial numbers (30%-60%) of children with elevated lipid levels. Drug treatment for dyslipidemia in children has been studied and shown to be effective only for suspected or proven familial monogenic dyslipidemias. Intensive dietary counseling and follow-up can result in improvements in lipid levels, but these results have not been sustained after the cessation of the intervention. The few trials of exercise are of fair-to-poor quality and show little or no improvements in lipid levels for children without monogenic dyslipidemias. Although reported adverse effects were not serious, studies were generally small and not of sufficient duration to determine long-term effects of either short or extended use.

CONCLUSIONS

Several key issues about screening and treatment of dyslipidemia in children and adolescents could not be addressed because of lack of studies, including effectiveness of screening on adult coronary heart disease or lipid outcomes, optimal ages and intervals for screening children, or effects of treatment of childhood lipid levels on adult coronary heart disease outcomes.

Children's descriptions of the foods consumed during loss of control eating episodes

Binge and loss of control (LOC) eating appear to be common among youth; however, little is known about the foods consumed during such eating episodes. Two-hundred forty-nine children, age 6-18 years, were interviewed to determine if they engaged in eating episodes with LOC over the past month. In the absence of reported LOC eating, overeating episodes or normal meals without LOC were recorded. Participants were asked to describe the type and quantity of foods eaten during an episode. Eighty-one children reported LOC eating episodes and 168 reported no such episodes (No LOC). Although total energy intake did not differ between LOC and No LOC episodes, LOC episodes consisted of a lower percentage of calories from protein (14.2+/-0.7 v. 18.0+/-0.7%, p<.001) and a higher percentage from carbohydrates (49.8+/-1.6 v. 45.2+/-1.1%, p<.05). Specifically, LOC episodes consisted of a higher percentage of calories from snacks (13.2+/-2.7 v. 7.4+/-1.2%, p<.05) and desserts (18.1+/-3.1 v. 12.8+/-1.5%, p<.05). The quality of LOC episodes may help explain why LOC eating promotes excessive weight gain among children who report such episodes.

Practitioner review: bridging the gap between research and clinical practice in pediatric obesity

BACKGROUND

Pediatric obesity is a significant public health concern, with rising prevalence rates in both developed and developing countries. This is of particular significance given that overweight children and adolescents are at increased risk for multiple medical comorbidities, as well as psychosocial and behavioral difficulties. The current review highlights findings from the empirical pediatric obesity treatment literature, with particular attention to diet, physical activity, and behavior interventions. Evaluation and treatment considerations relevant to working with overweight children and adolescents with psychiatric comorbidities are reviewed.

METHODS

Review of the relevant treatment literature, with a focus on randomized clinical trials, was conducted. Recommendations regarding treatment of children and adolescents with psychiatric comorbidities are based on relevant prospective studies of the relationship between weight status and psychological variables and studies with adult populations.

RESULTS

Well-established pediatric weight control interventions have been conducted in research settings. These studies provide a starting point, but are limited by homogeneous samples that may exclude participants with psychiatric comorbidities. Practitioners treating obese children and adolescents with psychiatric disorders are encouraged to assess individual, familial, and contextual variables specific to weight (e.g., motivation and existing support to change current eating and physical activity patterns, extent of weight-related conflict within family, impact of weight on current functioning) in order to prioritize treatment objectives.

CONCLUSIONS

The review concludes with a discussion of current empirical and practical challenges, including explicitly targeting obese children and adolescents with psychiatric concerns and determining appropriateness of pursuing weight control interventions in this population.

Systematic review of interventions in the management of overweight and obese children which include a dietary component

BACKGROUND

The prevalence of overweight and obesity in children and adolescents is increasing at an alarming rate around the world and prevention has become a key public health objective. Treatment and management of those already overweight and obese must be aligned with the best available evidence on effectiveness, if the risk of obesity-related morbidity and mortality is yet be reduced. Diet plays a pivotal role in successful treatment of obesity but to date, there is limited evidence on which to base practice.

OBJECTIVES

To identify and present the best available evidence on the optimal dietetic treatment and management of children and adolescent who are overweight or obese.

SEARCH STRATEGY

Published English language literature was searched using the electronic databases CINAHL, MEDLINE, PRE-MEDLINE, DARE, COCHRANE, EMBASE, AUSTROM, Current Concepts and Dissertation Abstracts. The databases were limited to English Language from 1975 until 2003. Government reports from the UK, USA and Australian were also searched and a hand search performed for the Journal of the Dietitians Association of Australia, International Journal of Obesity and the Journal of Human Nutrition and Dietetics and the bibliographies of retrieved articles.

SELECTION CRITERIA

(i) Interventions that evaluated the effectiveness of nutrition or dietary interventions to treat or manage overweight and obesity; (ii) Children aged less than 18 years; and (iii) Participants were defined as overweight or obese by relative weight or a measure of body weight status, studies that reported body weight per se were excluded.

DATA COLLECTION AND ANALYSIS

An experienced professional librarian searched the databases, and two trained research assistants independently identified studies for retrieval and assessed each article for inclusion. The included studies were critically appraised for methodological quality by two people independently. Data were extracted from the appropriate articles and when a discrepancy arose, a third party would arbitrate.

MAIN RESULTS

There were 116 articles that met the inclusion criteria. While 49 articles described randomised controlled trials, they arose from 37 separate studies. There were 67 non-randomised trials. Meta-analyses were performed on eight studies that included both a dietary intervention component and an adequate control group and on four studies that had follow-up data. There was a high degree of heterogeneity between studies and this made comparisons between studies problematic. Interventions that include diet therapy generally result in significant weight loss, at least in the short term. Many studies were poorly designed and had no or only minimal follow up. The details of the dietary intervention were often inadequately described and dietary outcomes rarely reported, making repetition of the studies difficult.

REVIEWERS' CONCLUSIONS

There is an urgent need for high quality studies investigating the optimal dietary approach to management of paediatric overweight and obesity. These studies require adequate follow up to ascertain if weight loss can be sustained in the long term. Details of the dietary prescription, adherence to the dietary intervention and diet-specific outcomes need to be reported in order to inform best practice.

Safety of drug therapies used for weight loss and treatment of obesity

Some of the medications used for weight loss in the management of obesity have been associated with unacceptable morbidity and mortality. Safety concerns have led to the withdrawal of aminorex, followed by the fenfluramines in 1997, and phenylpropanolamine (norephedrine) in 2000. Aminorex was associated with an increased prevalence of primary pulmonary hypertension (PPH), fenfluramines with an increased prevalence of PPH and valvulopathy, and phenylpropanolamine with an increased risk of haemorrhagic stroke. Several studies have investigated the safety of the fenfluramines, yet the benefit-risk profile has not been conclusively quantified. This is due to several deficiencies in the published studies, including a lack of data on the baseline prevalences of comorbid conditions in obese subjects, and potential confounders and biases in the study designs. Although several studies and systematic reviews support an increased risk of PPH and valvulopathy in patients who have taken fenfluramines, without knowledge of the background prevalence it is not possible to determine if the exposure preceded the outcome. The population at higher risk of these adverse effects includes those taking higher doses or with a longer duration of exposure to fenfluramines and those with pre-existing cardiac disease or a genetic predisposition. Patients exposed to fenfluramines continue to be monitored, with some follow-up studies indicating no overall worsening in valvulopathy over time. There are limited efficacy and safety data for amfepramone (diethylpropion) and phentermine and their approval for the management of obesity is limited to short-term use. Orlistat and sibutramine are the only currently approved medications for long-term management of obesity. Although the benefit-risk profiles of sibutramine and orlistat appear positive, sibutramine continues to be monitored because of long-term safety concerns. The safety and efficacy of currently approved drug therapies have not been evaluated in children and elderly patient populations and there is limited information in adolescents, whilst the long-term safety of current and potential new drug therapies in adults will require several years of postmarketing surveillance to fully elucidate their adverse effect profiles.

Pediatric Obesity: Impact and Surgical Management

The incidence of children in the United States who are overweight or obese is increasing at an alarming rate, and many obesity-related complications are now being described in children. There appears to be no current pharmacologic treatment or surgical procedure that is both safe and effective for millions of obese children. Bariatric surgery may be useful, however, in carefully selected obese children with associated serious comorbidities unresponsive to medical or dietary interventions. The complications of pediatric obesity are discussed, as well as current medical and surgical management of this disorder.

New drug policy in childhood obesity

OBJECTIVE

To update physicians, especially paediatricians, in the rapidly developing field of pharmacotherapy of childhood and adolescent obesity.

METHODS

The paper reviews current and investigational antiobesity drugs.

RESULTS

At present, there are only few drugs approved by the Food and Drug Administration (FDA) for the treatment of adult obesity. The most important ones are sibutramine and orlistat. The FDA in the USA approved the latter drug in 2003, and it has recently been approved by the European Union for the treatment of adolescents. There are several investigational antiobesity agents but only few new and promising substances like Rimonabant (a cannabinoid receptor antagonist) and axokine (ciliary neutrotrophic factor) are already at an advanced stage of development.

CONCLUSION

In adults, it seems to be justified using drugs for long-term treatment of 'medically important' obesity. Strict guidelines concerning the treatment of obese adolescents with orlistat are needed. It is only hoped that double-blind placebo-controlled studies investigating the new and promising drugs will also include adolescents and provide sufficient scientific data to get them licensed for the treatment of obese adolescents.

Pharmacotherapy for obesity

Pharmacotherapy for the management of obesity is primarily aimed at weight loss, weight loss maintenance and risk reduction, and has included thyroid hormone, amphetamines, phentermine, amfepramone (diethylpropion), phenylpropanolamine, mazindol, fenfluramines and, more recently, sibutramine and orlistat. These agents decrease appetite, reduce absorption of fat or increase energy expenditure. Primary endpoints used to evaluate anti-obesity drugs most frequently include mean weight loss, percentage weight loss and proportion of patients losing >or=5% and >or=10% of initial bodyweight. Secondary endpoints may include reduction in body fat, risk factors for cardiovascular disease and the incidences of diseases such as diabetes mellitus. Most pharmacotherapies have demonstrated significantly greater weight loss in patients on active treatment than those receiving placebo in short-term (<or=1 year) randomised controlled trials of pharmacological treatment in conjunction with a calorie-controlled diet or lifestyle intervention. The evidence of long-term efficacy is limited to sibutramine (2 years) and orlistat (4 years). These are the only drugs currently approved for the long-term management of obesity in adults. Sibutramine recipients randomised following 6 months' treatment to either sibutramine or placebo demonstrated significantly better weight maintenance at 2 years than those taking placebo (p<0.001), with >or=10% loss of initial bodyweight in 46% of patients. For patients taking orlistat, weight loss was 2.2 kg greater than those on placebo at 4 years (p<0.001), with significantly more patients achieving >or=10% loss of initial bodyweight (26.2% and 15.6%, respectively; p<0.001). Other drugs that have been evaluated for weight loss include ephedrine, the antidepressants fluoxetine and bupropion, and the antiepileptics topiramate and zonisamide. Two clinical trials with fluoxetine both reported no significant difference in weight loss compared with placebo at 52 weeks. Clinical trials evaluating ephedrine, bupropion, topiramate and zonisamide have demonstrated significantly greater weight loss than placebo but have been limited to 16-26 weeks' treatment. A major obstacle to the evaluation of the clinical trials is the potential bias resulting from low study completion rates. Completion rates varied from 52.8% of phentermine recipients in a 9-month study, to 40% of fenfluramine recipients in a 24-week comparative study with phentermine and 18% of amfepramone recipients in a 24-week study. One-year completion rates range from 51% to 73% for sibutramine and from 66% to 85% for orlistat. Other potential sources of bias include run-in periods and subsequent patient selection based on compliance or initial weight loss. Several potential new therapies targeting weight loss and obesity through the CNS pathways or peripheral adiposity signals are in early phase clinical trials. Over the next decade the drug treatment of obesity is likely to change significantly because of the availability of new pharmacotherapies to regulate eating behaviours, nutrient partitioning and/or energy expenditure.

Binge eating in overweight treatment-seeking adolescents

OBJECTIVE

To examine the frequency and recency of binge eating in relation to psychopathology in overweight, treatment-seeking adolescents.

METHODS

We investigated psychological correlates of the frequency and recency of reported loss of control (LOC) eating episodes in 160 overweight (body mass index [BMI]: 40.7 +/- 8.8 kg/m(2)) adolescents. On the basis of the responses to the eating disorder examination (EDE), participants were categorized into one of four groups: full-syndrome binge eating disorder (BED); recent but infrequent binge eating (episodes within the 3 months before interview; RECENT-BINGE); remote and infrequent LOC eating (episodes occurring >3 months before assessment; PAST-LOC), or no history of LOC episodes (NE).

RESULTS

The BED group reported higher EDE scores (global, p < .01), and more negative mood and anxiety than all other groups (p's < .01). Compared with NE, RECENT-BINGE also reported more anxiety and higher EDE scores (p's < .01).

CONCLUSIONS

Overweight, treatment-seeking adolescents with BED are clearly distinguishable from teens without the disorder on measures of eating-related psychopathology, mood, and anxiety. RECENT-BINGE, but not PAST-LOC, is also associated with significantly greater eating-related and general psychopathology.

Randomized, double-blind, placebo-controlled trial of orlistat for weight loss in adolescents

OBJECTIVE

To evaluate the efficacy of orlistat to enhance weight loss in obese adolescents.

METHODS

The study was a 6-month randomized, double-blind, placebo-controlled trial to compare the effects of orlistat (120 mg orally 3 times a day) and placebo on reduction of body mass index (BMI). Forty adolescents between 14 and 18 years of age with a mean BMI of 40 kg/m2 entered the protocol between December 2002 and February 2003. Study subjects stayed overnight in the General Clinical Research Center, during which dietary records were reviewed and lifestyle recommendations were given. The study participants received either orlistat (120 mg orally 3 times a day) or placebo and were assessed monthly for 6 months. At 0, 3, and 6 months, fasting laboratory tests were performed. The primary end point was the change in BMI from baseline to 6 months. Secondary outcomes included changes in weight, lean body mass, and results of blood chemistry studies.

RESULTS

No statistically significant difference was noted between the 2 study groups for decrease in BMI from baseline to 6 months (P = 0.39). The decrease in BMI within the orlistat group (-1.3 +/- 1.6 kg/m2; P = 0.04) and within the placebo group (-0.8 +/- 3.0 kg/m2; P = 0.02), however, was statistically significant. Laboratory measurements did not differ between the 2 groups. In comparison with the placebo group, the orlistat group had increased adverse events, primarily gastrointestinal symptoms and findings.

CONCLUSION

In this study of obese adolescents, orlistat did not significantly reduce BMI in comparison with placebo at 6 months.

Orlistat

Orlistat (Xenical) is a reversible inhibitor of gastric and pancreatic lipases. In conjunction with a hypocaloric diet and moderate exercise, orlistat is an effective drug for use in the management of obesity in adults with or without comorbidities. Recent data have shown that orlistat is also effective as a component of weight management strategies in obese adolescents. In addition to its well established efficacy in achieving modest weight loss, orlistat has been shown to improve glycaemic parameters in obese adults with type 2 diabetes mellitus as well as some features of the metabolic syndrome. Orlistat is generally well tolerated. Thus, orlistat is an option for the treatment of obese patients with or without type 2 diabetes and also has a role in the management of obese patients with the metabolic syndrome, associated comorbidities or concomitant disorders.

Vascular risks and management of obesity in children and adolescents

Childhood obesity has reached epidemic proportions in many countries. Pediatric obesity is associated with the development of cardiovascular (CV) risk factors including type 2 diabetes, hypertension, dyslipidemia, and the metabolic syndrome. It is also associated with an increased risk of CV disease (CVD) in adulthood. Moreover, obesity and CVD risk factors in obese youth tend to track into adulthood, further increasing the risk of adult CVD. Consequently, the treatment and prevention of childhood overweight and obesity has become a public health priority. Proper nutrition and increased physical activity are the main focus of these efforts; however, few studies have shown positive results. Treatment options for obesity in youth also include pharmacotherapy and surgery. While pharmacotherapy appears promising, additional evidence is needed, especially with respect to the long-term impact, before it becomes a widespread treatment option in the pediatric population.

Effect of orlistat, micronised fenofibrate and their combination on metabolic parameters in overweight and obese patients with the metabolic syndrome: the FenOrli study

BACKGROUND

Obesity is becoming increasingly common worldwide and is strongly associated with the metabolic syndrome (MetS). MetS is considered to be a cluster of risk factors that increase the risk of vascular events.

OBJECTIVE

In an open-label randomised study (the FenOrli study) we assessed the effect of orlistat and fenofibrate treatment, alone or in combination on reversing the diagnosis of the MetS (primary end-point) as well as on anthropometric and metabolic parameters (secondary end-points) in overweight and obese patients with MetS but no diabetes.

METHODS

Overweight and obese patients (N = 89, body mass index (BMI) > 28 kg/m2) with MetS [as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP) III criteria] participated in the study. Patients were prescribed a low-calorie low-fat diet and were randomly allocated to receive orlistat 120 mg three times a day (tid) (O group), micronised fenofibrate 200 mg/day (F group), or orlistat 120 mg tid plus micronised fenofibrate 200 mg/day (OF group). Body weight, BMI, waist circumference, blood pressure, serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C, triglyceride, creatinine (SCr) and uric acid (SUA) levels, as well as homeostasis model assessment (HOMA) index and liver enzyme activities were measured at baseline and after 3 months of treatment.

RESULTS

Of the 89 patients enrolled, three (one in each group) dropped out during the study due to side effects. After the 3-month treatment period, 43.5% of patients in the O group, 47.6% in the F group and 50% in the OF group no longer met the MetS diagnostic criteria (primary end-point, p < 0.0001 vs. baseline in all treatment groups). No significant difference in the primary end-point was observed between the three treatment groups. Significant reductions in body weight, BMI, waist circumference, blood pressure, TC, LDL-C, non-HDL-C, triglyceride and SUA levels, as well as gamma-glutamyl transpeptidase activity and HOMA index were observed in all treatment groups. In the OF group a greater decrease in TC (-26%) and LDL-C (-30%) was observed compared with that in the O and F groups (p < 0.01) and a more pronounced reduction of triglycerides (-37%) compared with that in the O group (p < 0.05). SUA levels and alkaline phosphatase activity decreased more in the F and OF groups compared with the O group (p < 0.05). Moreover, SCr significantly increased and estimated creatinine clearance decreased in the F and OF groups but they were not significantly altered in the O group (p < 0.01 for the comparison between O and either F or OF groups). Glucose (in groups O and OF), as well as insulin levels and HOMA index (in all groups), were significantly reduced after treatment (p < 0.05 vs. baseline).

CONCLUSION

The combination of orlistat and micronised fenofibrate appears to be safe and may further improve metabolic parameters in overweight and obese patients with MetS compared with each monotherapy.

Overweight in children and adolescents: pathophysiology, consequences, prevention, and treatment

The prevalence of overweight among children and adolescents has dramatically increased. There may be vulnerable periods for weight gain during childhood and adolescence that also offer opportunities for prevention of overweight. Overweight in children and adolescents can result in a variety of adverse health outcomes, including type 2 diabetes, obstructive sleep apnea, hypertension, dyslipidemia, and the metabolic syndrome. The best approach to this problem is prevention of abnormal weight gain. Several strategies for prevention are presented. In addition, treatment approaches are presented, including behavioral, pharmacological, and surgical treatment. Childhood and adolescent overweight is one of the most important current public health concerns.

Health-related quality of life in overweight and nonoverweight black and white adolescents

OBJECTIVES

To assess the impact of obesity on quality of life (QOL) in black and white adolescents.

STUDY DESIGN

One hundred ten overweight (body mass index [BMI], 41.7 +/- 8.9 kg/m2) and 34 nonoverweight adolescents (BMI, 20.6 +/- 2.9 kg/m2) and their parents completed measures of QOL.

RESULTS

Overweight was associated with poorer adolescent-reported QOL and parent reports of their children's QOL. Examining groups by weight status and race, overweight whites reported the greatest impairment on Social/Interpersonal, Self-Esteem, and Physical Appearance QOL (all P < .01), whereas parents of overweight blacks reported the poorest General Health Perceptions scores regarding their children. Interactions between BMI z-score and race were detected for Social/Interpersonal, Self-esteem, Daily Living, Self-Efficacy, Self-regard, and Physical Appearance QOL (all P < .05): Higher BMI in whites was associated with greater impairments in QOL than in blacks. Parents reported similar relations for their children.

CONCLUSIONS

According to adolescent and parent reports, overweight is associated with poorer QOL in adolescence, regardless of race; however, compared with overweight white adolescents, blacks report less impairment in QOL. Future research is required to determine whether differences in QOL are predictive of treatment success.

Pediatric obesity and insulin resistance: chronic disease risk and implications for treatment and prevention beyond body weight modification

The study of childhood obesity has continued to grow exponentially in the past decade. This has been driven in part by the increasing prevalence of this problem and the widespread potential effects of increased obesity in childhood on lifelong chronic disease risk. The focus of this review is on recent findings regarding the link between obesity and disease risk during childhood and adolescence. We describe recent reports relating to type 2 diabetes in youth (2), prediabetes (69, 166), metabolic syndrome (33, 35), polycystic ovarian syndrome (77), and nonalcoholic fatty liver disease (58, 146), and the mediating role of insulin resistance in these conditions. In addition, we review the implications of this research for the design of more effective treatment and prevention strategies that focus more on the improvement of obesity-related metabolic abnormalities and chronic disease risk reduction than on the conventional energy balance approach that focuses on weight management.

Effects of eight weeks of exercise training and orlistat therapy on body composition and maximal exercise capacity in obese females

A comparative assessment was made of the short-term effects of orlistat therapy and exercise training on body composition and aerobic fitness in obese females. A total of 24 obese patients were enrolled in to the study; 12 received orlistat therapy (DO) and 12 participated in a regular aerobic exercise-training programme (DE). All patients were on hypocaloric diets. Each patient performed three incremental ramp exercise tests (one at Week 0, one at the end of Week 4 and one at the end of Week 8) to exhaustion using an electromagnetically braked cycle ergometer to determine their anaerobic threshold and maximal exercise (Wmax) capacity. Patients in the DE group performed continuous exercise at a work rate that corresponded to the anaerobic threshold. Weight loss and loss of fat mass after 8 weeks were -6.4% (P=0.002) and -13.4% (DE) vs -5.8% (P=0.002) and -6.4% (P=0.008) (DO), respectively. Wmax capacity was 90.8+/-5 W (basal) vs 92.9+/-5 W (Week 4, P=0.1) and 100.4+/-6 W (Week 8, 10.5%, P=0.04) in the DO group, and 96.2+/-6 W (basal) vs 129.1+/-4 W (Week 4, 34.1%, P=0.002) and 137.5+/-5 W(Week 8, 42.9%, P=0.002) in the DE group. Despite similar decreases in body weight in both groups, patients in the DE group achieved a markedly higher level of Wmax, reflecting a better improvement in cardiopulmonary fitness, compared with patients in the DO group. Considering the improvement of aerobic fitness in the short term, an aerobic exercise-training programme should be considered for sedentary obese patients to improve their aerobic fitness and thereby reduce the negative outcomes of obesity.

Childhood obesity. Treatment options

The prevalence of child and adolescent overweight and obesity is rapidly increasing and is associated with morbidity, both medical and psychosocial. Obesity is unlikely to resolve spontaneously. It is important that health professionals can assess obesity and initiate an action plan. The evidence base for what works best in the management of child and adolescent overweight and obesity is limited. It is uncertain whether protocols from clinical research trials can be translated into primary care. Dietary change, with an emphasis on lower fat intake and smaller portion size, should be commenced. There should be an increase in physical activity and a decrease in sedentary behaviours, combined with behavioural change and parental involvement. These are the elements of a lifestyle intervention. In the severely obese adolescent with obesity-related co-morbidity, the use of very low-energy diets and anti-obesity agents could be considered. Bariatric surgery may be indicated in carefully selected, older, severely obese adolescents.

Co-occurrence of two partially inactivating polymorphisms of MC3R is associated with pediatric-onset obesity

Both human linkage studies and MC3R knockout mouse models suggest that the MC3R may play an important role in energy homeostasis. Here we show that among 355 overweight and nonoverweight children, 8.2% were double homozygous for a pair of missense MC3R sequence variants (Thr6Lys and Val81Ile). Such children were significantly heavier (BMI and BMI SD score: P < 0.0001), had more body fat (body fat mass and percentage fat mass: P < 0.001), and had greater plasma leptin (P < 0.0001) and insulin concentrations (P < 0.001) and greater insulin resistance (P < 0.008) than wild-type or heterozygous children. Both sequence variants were more common in African-American than Caucasian children. In vitro expression studies found the double mutant MC3R was partially inactive, with significantly fewer receptor binding sites, decreased signal transduction, and less protein expression. We conclude that diminished MC3R expression in this double MC3R variant may be a predisposing factor for excessive body weight gain in children.

Body mass index extremes in a British adolescent gynecology clinic

STUDY OBJECTIVE

To identify the prevalence of patients with BMI extremes (BMI>88% or < 2%) in our Adolescent Gynecology clinic and audit their weight management.

DESIGN

Retrospective case series.

SETTING

The Adolescent Gynecology Clinic of a British District General Hospital

PARTICIPANTS

All patients aged 12-17 years when first seen in the Adolescent Gynecology clinic from 1997 to 2003.

INTERVENTIONS

Retrospective data collection on biometry and weight management interventions.

MAIN OUTCOME MEASURES

The percentage of obese (BMI>98(th) percentile for age), overweight (BMI 88(th)-98(th) percentile) and underweight (BMI < 2(nd) percentile) based on published percentile BMI curves for the UK adolescent population, the proportion of patients with extreme BMI that were offered intervention, the types of intervention offered, the proportion of patients whose BMI improved after the intervention, and the number of patients with BMI>88% among smokers were compared to non-smokers.

RESULTS

Of the 125 patients 24% were obese, an additional 17% overweight and 1% underweight. The expected figures in the general population are 2%, 10% and 2% respectively (P < 0.001; test of a single proportion). Weight management intervention was offered to 47% of patients with extreme BMI. The BMI improved in 36% of the patients who were offered and 14% of patients who were not offered intervention (P=0.066; chi(2)). There was no statistically significant difference between smokers and non-smokers in the proportion of patients with BMI>88% (P=0.93; chi(2)).

CONCLUSION

There is significantly increased prevalence of obese and overweight women among adolescent gynecological patients. The need for management of the BMI of these patients has not been always been recognized and treatment is not particularly effective. The results indicate a need for defined strategies and additional resources for obesity management.

Influence of excess adiposity on exercise fitness and performance in overweight children and adolescents

OBJECTIVE

Relatively little is known about how excess body mass affects adolescents' capacity to perform sustained exercise. We hypothesized that most of the difficulty that severely overweight adolescents have with sustained exercise occurs because the metabolic costs of moving excess mass result in use of a high proportion of their total oxygen reserve.

METHODS

We compared results from a maximal cycle ergometry fitness test in 129 severely overweight adolescents who had BMIs of 41.5 +/- 9.7 kg/m2 and ages of 14.5 +/- 1.8 years (range: 12.1-17.8 years) and 34 nonoverweight adolescents who had BMIs of 20.1 +/- 2.9 kg/m2 and ages of 14.5 +/- 1.5 years (range: 12.0-18.1 years). Oxygen uptake (Vo2) was compared at 3 times: during a 4-minute period of unloaded cycling (ULVo2), at the lactate threshold estimated by gas exchange (LTVo2), and at maximal exertion (Vo2 max). Heart rate was obtained at rest and at Vo2 max. Participants also completed a 12-minute walk/run performance test to obtain distance traveled (D12) and heart rate.

RESULTS

Absolute LTVo2 and Vo2 max and LTVo2 as a percentage of Vo2 max were not different in overweight and nonoverweight adolescents during the cycle test. However, absolute ULVo2 was significantly greater in overweight adolescents: ULVo2 accounted for 35 +/- 8% of Vo2 max (and 63 +/- 15% of LTVo2) in overweight adolescents but only 20 +/- 5% of Vo2 max (and 39 +/- 12% of LTVo2) in nonoverweight adolescents. Resting heart rate before initiating the cycle test was significantly greater in overweight than nonoverweight adolescents (94 +/- 14 vs 82 +/- 15 beats per minute). However, maximal heart rate during the cycle test was significantly lower in overweight adolescents (186 +/- 13 vs 196 +/- 11 beats per minute). During the walk/run test, mean D12 was significantly shorter for overweight than for nonoverweight adolescents (1983 +/- 323 vs 1159 +/- 194 m). D12 was negatively related to BMI SDS (r = -0.81) and to ULVo2 (r = -0.98).

DISCUSSION

Overweight and nonoverweight adolescents had similar absolute Vo2 at the lactate threshold and at maximal exertion, suggesting that overweight adolescents are more limited by the increased cardiorespiratory effort required to move their larger body mass through space than by cardiorespiratory deconditioning. The higher percentage of oxygen consumed during submaximal exercise indicates that overweight adolescents are burdened by the metabolic cost of their excess mass. Their greater oxygen demand during an unloaded task predicted poorer performance during sustained exercise. Exercise prescriptions for overweight adolescents should account for the limited exercise tolerance imposed by excess body mass, focusing on activities that keep demands below lactate threshold so that exercise can be sustained.