Newsletters - February 2010
Comprehensive Obesity Management: the Multidisciplinary Approach
by Bradley R. Javorsky, MD, Assistant Professor of Medicine
“To promise not to do a thing is the surest way in the world to make a body want to go and do that very thing.” MARK TWAIN
Over the last several decades, the understanding of appetite regulation and obesity management has increased enormously. The impetus for this research has grown from the alarming increase in the prevalence of obesity and its medical, social and economic consequences. Few conditions frustrate physician and patient alike as does treatment of excess weight. No doubt, this is related to the paucity of treatment options available and the difficulty in trying to change genetically and environmentally entrenched behaviors. For many patients, long-term success with diet alone is disappointing, on the order of 5 percent weight loss at one year follow up. Similar results are observed with exercise, behavioral interventions, or pharmacotherapy alone. Combined, however, these strategies can result in weight loss of 10 percent to 15 percent.
Bariatric surgery remains the most effective means of achieving weight loss. Maximum weight loss is observed around one year, resulting in a 38 percent decrease for gastric bypass and a 21 percent decrease for gastric banding. At 10 years of follow up, weight loss remains decreased by 25 percent for gastric bypass and 13 percent for gastric banding. Bariatric surgery, however, is not a feasible option for many patients. For some, the stigma or complications of surgery are deemed unacceptable. For others, health insurance coverage is unavailable or eligibility criteria cannot be fulfilled.
The most effective strategies employ a multidisciplinary team working in concert to achieve individualized weight loss goals. This includes the endocrinologist, dietitian, exercise physiologist, behavioral therapist and bariatric surgeon. To this end, a centralized, comprehensive obesity management approach is available at Froedtert & The Medical College of Wisconsin. The goal of this union is to facilitate patient referrals to
the appropriate specialist and maintain continuity of care.
The role of the endocrinologist (or equivalent medical provider) is to assess risk based on the type and severity of obesity, evaluate for secondary causes of obesity, evaluate and treat complications of obesity such as diabetes and dyslipidemia, coordinate care among other team members, prescribe pharmacotherapy, and prepare the patient for bariatric surgery when appropriate.
The etiology of obesity in most patients is a combination of genetic predisposition and lifestyle factors. However, some treatable medical conditions present as obesity and should be promptly identified. These include thyroid disorders, medication side effects (e.g., from glucocorticoids, anti-psychotics/anti-depressants, antiretroviral therapy and insulin), Cushing’s syndrome, hypothalamic tumors, depression, insulinoma, and genetic conditions such as Prader-Willi syndrome.
Diet and exercise remain the cornerstone of obesity therapy with or without pharmacotherapy and bariatric surgery. There are numerous popular weight loss diets with varying macronutrient compositions. Many large, controlled clinical studies have concluded that all perform comparably; only adherence and calorie content appear to be important for weight loss. An experienced dietitian will help patients find a diet that is appropriate for medical needs, fits with lifestyle, and that has a calorie deficit. Similarly, an exercise physiologist assesses a patient’s capacity for exercise and prescribes a regimen that can be done at home, at a local gym or in one-on-one sessions.
Many patients have difficulty making healthy choices because of psychological stress, depression, anxiety and learned behaviors. Behavioral therapists work with patients on stress management, goal setting, problem solving, stimulus control, self-monitoring and reinforcement. Behavioral therapy has been shown to have significant effects on weight loss, especially when added to diet and exercise. A Cochrane review found that patients treated with psychological interventions, plus diet and exercise lost an additional 4.7 kg compared with diet and exercise alone.
Pharmacotherapy for obesity is still in its infancy. Currently, there are only two FDA-approved medications for long-term use in obesity management — sibutramine (Meridia®) and orlistat (Xenical®). Orlistat is also now available over the counter as Alli®. These medications are only recommended for patients with an initial BMI ≥ 30 kg/m2, or BMI ≥ 27 kg/m2 with other risk factors (e.g., diabetes, high cholesterol, controlled high blood pressure). Combined with lifestyle and behavioral changes, these medications can achieve a weight loss of 10 percent to 12 percent.
There are many medications now in phase I, II and III clinical trials. Although none have yet matched the weight loss achieved with bariatric surgery, several have fulfilled efficacy and safety criteria and are in the process of seeking FDA approval.
Lorcaserin is the first agent in a new class of selective serotonin 2C receptor agonists. This receptor is expressed in the hypothalamus, an area involved in the control of appetite and metabolism. Two combination drugs, phentermine/topiramate and naltrexone/bupropion, boast greater weight loss and tolerability than the individual compounds they are made from. Finally, pramlintide, a functional analog of the naturally occurring pancreatic hormone amylin (which is currently FDA-approved for the treatment of type 1 and type 2 diabetes mellitus), has shown promise in trials of obese patients without diabetes mellitus, especially when added to recombinant methyl-human leptin.
Endocannabinoid receptor antagonists such as rimonabant initially demonstrated great promise, but were denied approval by the FDA because of adverse psychological effects, including suicidality. Second generation agents with peripheral activity may prove effective with fewer central complications.
For many patients, sufficient or sustained weight loss cannot be achieved despite great efforts from the patient and healthcare team. It is an important job of the treating physician to recognize these patients and determine the appropriateness of referral to an experienced bariatric surgeon. Current guidelines reserve surgery for patients with BMI ≥ 40 kg/m2, or BMI ≥ 35 kg/m2 with obesity-related co-morbidities. Many insurance companies require three to six months of physician supervised weight loss therapy prior to making patients eligible for bariatric surgery. Physicians must, therefore, be forward-thinking to ensure criteria are met to prevent unnecessary delays in patients receiving appropriate care.
A careful transition to bariatric surgery is important since dietary requirements after surgery are often different than standard weight loss diets. Adherence to specific recommendations for meal size, frequency and macronutrient composition is essential for maximal weight loss, sustained weight loss and prevention of surgical complications.
Finally, close collaboration between surgeon and endocrinologist facilitates monitoring of metabolic complications of obesity, as well as issues that may arise postoperatively, including bone loss and micronutrient deficiencies.
Dr. Javorsky can be reached at 262-253-7155 or firstname.lastname@example.org.
- Sacks FM, Gray GA, Carey VJ et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. New England Journal of Medicine 2009;360(9):859-73.
- Shaw KA, O’Rourke P, Del Mar C, Kenardy J. Psychological interventions for overweight or obesity. Cochrane Database of Systematic Reviews 2005, Issue 2.
- Sjostrom L, Narbro K, Sjostrom CD et al. Effects of bariatric surgery on mortality in Swedish obese subjects. New England Journal of Medicine 2007;357(8):741-52.
- Sjostrom L, Rissanen A, Andersen T et al. Randomized placebo-controlled trial of orlistat for weight loss and prevention of weight regain in obese patients. Lancet 1998; 352:167–73.
- Smith SR, Aronne LJ, Burns CM et al. Sustained weight loss following 12-month pramlintide treatment as an adjunct to lifestyle intervention in obesity. Diabetes Care 2008;31(9):1816–1823.
- Wadden TA, Berkowitz RI,Womble LG et al. Randomized trial of lifestyle modification and pharmacotherapy for obesity. New England Journal of Medicine 2005;353(20):2111-20.