[Bariatric surgery: 10-year results of the Swedish Obese Subjects Study]

Abstract

The 10-year results of the prospective, controlled Swedish Obese Subjects Study were recently reported in the New England Journal of Medicine by L. Sjöström and colleagues. This trial compared obese subjects who underwent gastric surgery and contemporaneously matched, conventionally treated obese control subjects. The follow-up rate for laboratory examinations was 74.5 percent at 10 years. At that time, data of 627 patients of the control group (mean age of 48 years, body mass index of 41 kg/m2) were compared to those of 641 patients who were submitted to surgery (banding n = 156, vertical banded gastroplasty n = 451 and gastric bypass n =34). At 10 years, the body weight had increased by 1.6 percent in the control group and decreased by 16.1 percent in the surgery group (p < 0.001), and similar changes were observed for waist circumference (+2.8 percent versus -10.1 percent, respectively, p < 0.001). Energy intake was lower and the proportion of physically active subjects higher in the surgery group than in the control group throughout the observation period. Ten-year rates of recovery from diabetes, hypertriglyceridaemia, low levels of high-density lipoprotein cholesterol, hypertension, and hyperuricaemia were more favourable in the surgery than in the control group. The surgery group had lower 10-year incidence rates of diabetes, hypertriglyceridaemia, and hyperuricaemia (but not of hypertension) than the control group. In conclusion, as compared with conventional therapy, bariatric surgery appears to be a valuable option for the treatment of severe obesity, resulting in long-term weight loss, improved lifestyle, and, except for hypercholesterolaemia that was not significantly affected, amelioration in cardiovascular risk factors that were elevated at baseline. Obtaining long-term data concerning the effect of weight loss on overall mortality and on the incidence rates of myocardial infarction, stroke, and cancer remains a key-objective of this landmark study.