Pounds of prevention: obesity therapy

Two Family Interventions to Reduce BMI in Low-Income Urban Youth: A Randomized Trial

BACKGROUND

Our primary aim was to evaluate the effects of 2 family-based obesity management interventions compared with a control group on BMI in low-income adolescents with overweight or obesity.

METHODS

In this randomized clinical trial, 360 urban-residing youth and a parent were randomly assigned to 1 of 2 behaviorally distinct family interventions or an education-only control group. Eligible children were entering the sixth grade with a BMI ≥85th percentile. Interventions were 3 years in length; data were collected annually for 3 years. Effects of the interventions on BMI slope (primary outcome) over 3 years and a set of secondary outcomes were assessed.

RESULTS

Participants were primarily African American (77%), had a family income of <25 000 per year, and obese at enrollment (68%). BMI increased over time in all study groups, with group increases ranging from 0.95 to 1.08. In an intent-to-treat analysis, no significant differences were found in adjusted BMI slopes between either of the family-based interventions and the control group (P = .35). No differences were found between the experimental and control groups on secondary outcomes of diet, physical activity, sleep, perceived stress, or cardiometabolic factors. No evidence of effect modification of the study arms by sex, race and/or ethnicity, household income, baseline levels of child and parent obesity, or exposure to a school fitness program were found.

CONCLUSIONS

In this low-income, adolescent population, neither of the family-based interventions improved BMI or health-related secondary outcomes. Future interventions should more fully address poverty and other social issues contributing to childhood obesity.

Clinical trial issues in weight-loss therapy

BACKGROUND

Overweight and obesity rates continue to increase nationally, generating significant interest in weight-loss therapies to address both the burden of obesity-associated chronic disease and individual concerns about appearance. Effective obesity therapies also have the potential for off-label use and unintended consequences.

METHODS

The behavioral, pharmacologic, and surgical therapies for obesity are reviewed. Clinical trial issues common to chronic disease states and issues specific to obesity trials are examined. Finally, study designs for obesity therapy, including populations, control arms, sample size, and duration of therapy, are discussed.

Anti-obesity drug development

Obesity accelerates morbidity and mortality and has been described by the World Health Organization (WHO) as an epidemic in many industrialised nations [101,102]. Diet, exercise and lifestyle recommendations have proven to be mostly ineffective in adequately preventing or treating the progression of this public health disease. Existing drug treatment is limited by the scarce number of safe and well-tolerated drugs with proven long-term efficacy in maintaining weight loss. Numerous anti-obesity drugs in development have promise. Yet, despite that obesity is the single most common nutritional problem in many developed nations and despite the devastating health consequences of this unchecked epidemic, investigational anti-obesity drugs face unique and significant challenges due to past and current experiences with anti-obesity drugs. It is anticipated that new anti-obesity drugs for this serious, multifaceted metabolic disease will become as safe and effective and as medically accepted as the treatment of other metabolic disorders such as hypertension, dyslipidaemia or Type 2 diabetes mellitus. This may be particularly important, given that these metabolic disorders may be largely due to or exacerbated by obesity itself.

Pharmacotherapy of obesity: currently marketed and upcoming agents

In many industrialized nations, obesity is now considered an epidemic, resulting in accelerated morbidity and mortality. Obesity is associated with an increased risk of coronary artery disease as well as the metabolic syndrome comprising abdominal obesity, increased fasting blood glucose levels, dyslipidemia and hypertension, which are all recognized cardiovascular risk factors. Diet, exercise, and lifestyle changes constitute important recommendations for treatment. Unfortunately, although effective in some individuals, these recommendations have proven to be ineffective in adequately addressing the broad, enlarging scope of this public health problem. Drug treatment is often indicated but is somewhat limited by the minimal number of well tolerated drugs that have proven to have long-term efficacy in maintaining bodyweight loss. For example, phentermine may result in modest bodyweight loss through suppression of appetite, but potential cardiovascular adverse effects exist and the efficacy is mainly short-term. Sibutramine, an inhibitor of serotonin and norepinephrine (noradrenaline) reuptake, may increase satiety and result in modest bodyweight loss. However, cardiovascular adverse effects may occur in susceptible patients. Nonetheless, sibutramine is one of the few drugs that has been approved by the US Food and Drug Administration (FDA) for bodyweight loss. Orlistat, a lipase inhibitor, is also approved by the FDA for bodyweight loss but may have bothersome gastrointestinal adverse effects, especially among patients who do not adhere to the recommended low-fat diet. Ongoing studies continue to evaluate other drug treatments that may result in bodyweight reduction through a number of different mechanisms. It is anticipated that the development of effective and well tolerated antiobesity drugs will elevate the pharmacologic treatment of obesity to the status of other cardiovascular risk factors and metabolic disorders. This may be especially important given that dyslipidemia, hypertension and type 2 diabetes mellitus are often secondary to, or exacerbated by, obesity.