Severe obesity is associated with multiple comorbidities (such as hypertension and diabetes) that can decrease life expectancy. Gastric bypass (GBP) surgery for severe obesity can positively affect hypertension and diabetes. Sugerman and associates performed a retrospective review of patients who had diabetes or hypertension and underwent GBP.

Of the 1,025 patients who had GBP, 15 percent had diabetes, and 51 percent had hypertension. One to 2 years postoperatively, patients reported an average significant weight loss of 50 kg (110 lb). Hypertension and diabetes resolved in 69 percent and 83 percent, respectively. There was significant improvement in many other obesity comorbidities, including sleep apnea, gastroesophageal reflux symptoms, and venous stasis disease.

One half of patients were followed five to seven years postoperatively. Average weight loss was higher at five to seven years than at one to two years. Resolution rates for hypertension and diabetes were similar. Thirty-seven percent of patients were followed for 10 to 12 years postoperatively. Of the 37 percent, all patients maintained their weight loss.

The authors conclude that there is a significant improvement in diabetes, hypertension, and other obesity comorbidities in severely obese patients after GBP. Current pharmacologic therapy for obesity is associated with a 10 percent weight loss that is probably inadequate to control diabetes and hypertension in many of these severely obese patients. The observation that many severely obese patients had either hypertension or diabetes alone hints that insulin resistance and hypertension can simply coexist in severely obese patients without a specific, unifying causal relationship.

editor's note: Obesity is an independent risk factor for myocardial infarction, hypertension, hypercholesterolemia, and impaired glucose tolerance. Surgery for morbid obesity is usually the last-resort intervention in patients who have tried all other weight-reduction treatments. Persons with morbid obesity, defined as a body mass index (BMI) of 40 or more, and those with less severe obesity (BMI of 35 to 39) but serious comorbidities such as arthritis, diabetes, back or disc disease, hypertension, hiatal hernia, fatigue, or elevated serum cholesterol levels, are appropriate candidates.

Characteristics of patients who will do well with surgery include no preoperative risk factors, a stable personality, no eating disorders, and the ability to comply with a diet demonstrated by a preoperative weight reduction to a BMI of 35 or less with medical treatment.GBP is a major operation that is difficult to reverse. Complications are rare but can include staple failure, leaks at newly created junctions, and spontaneous blockage at the anastomosis site. Vomiting, wound hernia, obstruction, anemia, and dumping syndrome can occur. However, surgery can result in a greater weight loss than medical management (23 to 28 kg [50 to 61 lb] more weight loss in two years), with improved quality of life and comorbidities (see Colquitt J, et al. Surgery for morbid obesity. Cochrane Database Syst Rev 2003: CD003641).—R.S.