Reimagining Obesity in 2018: A JAMA Theme Issue on Obesity.

TLDR: Outcomes for gastric sleeve resection are nearly as good as they are for Roux-en-Y gastric bypass, and that these outcomes are durable, suggesting that the major health effects from bariatric surgery are related to inducing weight loss and controlling diabetes.

Abstract: Six years ago, when JAMA last published a theme issue on obesity, there was optimism that progress was being made in preventing and treating obesity.1 As time has passed, so too has the optimism, as reports continued to show that the prevalence of obesity was increasing2 and, most important, rapidly increasing in children.3 A year and a half ago, there was a call to reconsider obesity and view it in new ways with the hope of better managing this very consequential clinical problem.4 In response, JAMA has revisited obesity in the form of a theme issue. This issue of JAMA includes 5 Original Investigations about bariatric surgery. Despite many bariatric surgery publications, most studies are not definitive due to lack of complete or long-term follow-up.5 Relatively few randomized trials have been conducted and, of those, not many involve multiple surgeons or institutions. The 5 studies published in this week’s JAMA overcome some of these limitations.6-10 Three randomized clinical trials were performed in multiple centers, with surgery performed by several different physicians. Each trial presents 5-year outcome data with very little loss to follow-up. Two observational studies compared bariatric surgery outcomes with either specialized obesity management or usual care and also have 4to 5-year outcomes, with nearly complete follow-up. Three of the Original Investigations in this issue of JAMA provide important information about the laparoscopic gastric sleeve operation.6-8 This procedure is relatively easy to perform and has rapidly become one of the most commonly performed bariatric procedures, despite the lack of high-quality evidence to support its use. The articles in this issue demonstrate that outcomes for gastric sleeve resection (including survival, excess BMI or weight loss, and improvement of comorbidities) are nearly as good as they are for Roux-en-Y gastric bypass, and that these outcomes are durable. Despite Roux-en-Y gastric bypass being a more complicated and technically difficult operation to perform, long-term complication rates are about the same for the 2 procedures. Although laparoscopic sleeve resection has good outcomes, a substantial number of patients develop gastroesophageal reflux disease after the procedure.6,7 Considering all the evidence, it is clear that laparoscopic gastric sleeve resection is a reasonable approach for treating significant obesity. However, as discussed in an accompanying Editorial by Arterburn and Gupta,11 there is no clear way to decide whether to perform gastric sleeve resection or Roux-en-Y gastric bypass. Bariatric surgery results in substantial and sustained weight loss, and it is associated with other important health outcomes. Although bariatric surgery may improve mortality, the effect is small,8 whereas the effect on remission of type 2 diabetes is substantial. The benefits of weight loss surgery on other obesity-related comorbidities are less clear. In one of the observational studies in this issue of JAMA, patients who had undergone bariatric surgery, compared with patients in the control group who had been enrolled in a specialized medical treatment program, had reduced use of medications for hypertension and hyperlipidemia.10 In another observational study in this issue, patients who had undergone bariatric surgery did not have a reduction in medication used for hypertension and dyslipidemia.8 Intuitively, this difference in results makes sense because hypertension is common in nonobese patients, and statins have other benefits in addition to treating dyslipidemia. It is unlikely that patients who have lost weight following bariatric surgery would be able to discontinue these medications. This finding suggests that the major health effects from bariatric surgery are related to inducing weight loss and controlling diabetes. The benefit of surgically induced weight loss on other outcomes, such as sleep apnea and osteoarthritis, were not addressed in these studies and more information is needed about how these complications of obesity might respond to bariatric surgery. In an effort to reverse the inexorable rise in the rates of obesity, some communities have imposed a tax on sugar sweetened beverages (SSBs) in an effort to reduce consumption of these products. Taxes are imposed on the distributors of SSBs, although it is not known if the distributors would absorb the cost or pass it on to consumers. As described by Cawley et al in a Research Letter in this issue of JAMA,12 SSB taxes imposed in Philadelphia, Pennsylvania, provided a unique opportunity to test this hypothesis. The Philadelphia airport is so large, it straddles 2 cities: 21 stores in the airport are in the city of Philadelphia and 10 stores are in the city of Tinicum. Only stores on the Philadelphia side were subject to the SSB tax. After the tax was imposed, SSB prices increased in all the stores but the increase was significantly higher in the stores subjected to the SSB tax, suggesting that taxes were being passed on to the consumer and that competitors not subject to the tax also, to a lesser degree, increased prices.12 These results are discouraging. In a related Viewpoint, Powell and Maciejewski13 discuss the economic implications of SSB taxes and how these taxes Viewpoints pages 221, 223, 225, 227, 229, and 231