MKSAP quiz: Treatment plan for obesity and diabetes

This month's quiz asks readers to evaluate a 42-year-old-man with type 2 diabetes, hypertension, and hyperlipidemia for obesity treatment.

A 42-year-old-man is evaluated for obesity. His weight has gradually increased over the past two decades and is currently 168.2 kg (370 lb). Five years ago, he was diagnosed with type 2 diabetes mellitus, hypertension, and hyperlipidemia. Over the past 6 months, he has unsuccessfully tried diet and exercise therapy for his obesity. He tried over-the-counter orlistat but could not tolerate the gastrointestinal side effects. Medications are metformin, lisinopril, and simvastatin. His total weight loss goal is 45.4 kg (100 lb).

On physical examination, temperature is normal, blood pressure is 130/80 mm Hg, pulse rate is 80/min, and respiration rate is 14/min. BMI is 48. Waist circumference is 121.9 cm (48 in). There is no thyromegaly. Heart sounds are normal with no murmur. There is no lower extremity edema.

Results of complete blood count, thyroid studies, and urinalysis are unremarkable.

Which of the following is the most appropriate management of this patient?

A. Bariatric surgery evaluation
B. Prescribe phentermine
C. Reduce caloric intake to below 800 kcal/d
D. Refer to an exercise program

MKSAP Answer and Critique

The correct answer is A. Bariatric surgery evaluation. This item is available to MKSAP 16 subscribers as item 150 in the General Internal Medicine section. Information about MKSAP 16 is available online.

This patient should be referred for bariatric surgery. For patients with class III obesity (BMI ≥40) or class II obesity (BMI 35.0-39.9) with obesity-related complications, the National Institutes of Health Consensus Development Conference recommends consideration of bariatric surgery if diet, exercise, and/or medication are ineffective. Patients should be motivated and well informed about this option and undergo multidisciplinary evaluation by a medical, surgical, psychiatric, and nutritionist team. The most common procedure is gastric bypass surgery, but laparoscopic banding is becoming common, as well. Bariatric surgery results in more dramatic and sustained weight loss than nonsurgical interventions and leads to improvement in obesity-related complications (diabetes mellitus, obstructive sleep apnea, hypertension, and hyperlipidemia). This patient has not attained his goal weight loss after a 6-month trial of diet and medication and has obesity-related complications that likely will improve with weight loss.

Phentermine is a sympathomimetic drug that is FDA-approved for short-term use (up to 12 weeks) as an adjunctive treatment of obesity. This patient's weight loss goal is 45.4 kg (100 lb), which will take much longer than 12 weeks. In addition, most persons regain any weight that is lost with this medication upon its discontinuation.

Restricting caloric intake to below 800 kcal/d (a very-low-calorie diet) is no more effective for long-term weight loss than a moderate strategy of restricting intake to 500-1000 kcal/d below what is estimated to maintain current body weight. In addition, long-term compliance with a very-low-calorie diet is nearly impossible.

Exercise is an important part of a comprehensive weight loss program that focuses on lifestyle modification. However, the patient has already not benefited from an exercise program. It is unlikely that exercise alone will meet his weight loss goals.

Key Point

  • Bariatric surgery should be considered for patients with BMI of 40 or greater or BMI of 35.0 to 39.9 with obesity-related complications in whom diet, exercise, and/or medication are ineffective.