Until recently, bariatric surgery was considered a cosmetic operation with little physiologic importance. A series of preliminary randomized clinical trials, however, have suggested that bariatric surgery may have importance in mitigating the adverse pathophysiology associated with obesity, including type 2 diabetes and some cardiovascular risk factors.
The finding of a surgical method of modifying this disease, which has occupied research for the last century, is somewhat unexpected after the many false starts associated with medical interventions. The two most popular surgical procedures, the gastric bypass and the sleeve gastrectomy performed using laparoscopic techniques, are currently being performed in obese patients with BMIs of greater than 35 with very low morbidly and rare mortality events. Several nonrandomized and prospective trials have examined the effect of bariatric surgery and reported beneficial effects on diabetes regression and significant reduction in major cardiovascular disease ( JAMA 2012;307:56-65).
The recent report of the 3-year follow-up of the STAMPEDE (Surgical Therapy And Medications Potentially Eradicate Diabetes Efficiently) trial ( N. Engl. J. Med. 2014;370:2002-13) provides additional physiologic information on the benefits of bariatric surgery in 150 obese diabetic patients aged 20-60 years with BMIs of 27-43, compared with intensive medical therapy. Patients were randomized to three arms: intensive medical therapy, gastric bypass, or sleeve gastrectomy. Most of the patients were white women with a history of diabetes for 8.3 years; the mean hemoglobin A1c was 9.3%. At baseline, 43% of the patients required insulin therapy. The primary endpoint was the achievement of HbA1c of 6% or less, which was achieved in 5% of the medically treated patients, compared with 38% in the gastric bypass group and 24% in the sleeve gastrectomy group. Decrease in BMI was the only measure that predicted the achievement of the HbA1c endpoint. Body weight decreased by 4.5% in the intensive medical group, 24.5% in the gastric bypass group, and 21.1% in the sleeve gastrectomy group. Significant decreases in low-density lipoprotein cholesterol and increases in high-density lipoprotein cholesterol were achieved in both surgical intervention groups, compared with the intensive medical care group. In addition, medical control of diabetes was improved and 69% and 43% of the gastrectomy and sleeve bypass group, respectively, were no longer requiring insulin therapy. There was, however, no significant difference in the change in blood pressure in the three groups. There were no life-threatening complications or deaths in the groups, but there were a number of complications associated with the procedure.