Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Metabolic Outcomes After Gastric Bypass Surgery

N Engl J Med; 2017 Sep 21; Adams, et al

Roux-en-Y gastric bypass had long-term durability of weight loss and remission and prevention of type 2 diabetes (T2D), hypertension, and dyslipidemia for 12 years after surgery. This according to follow-up of results of an observational, prospective study of Roux-en-Y gastric bypass conducted in the US. 1,156 patients with severe obesity comprised 3 groups: 418 patients who sought and underwent Roux-en-Y gastric bypass (surgery group), 417 patients who sought but did not undergo surgery (nonsurgery group 1), and 321 patients who did not seek surgery (nonsurgery group 2). Clinical examinations were performed at baseline and at 2, 6, and 12 years. Researchers found:

  • Adjusted mean change from baseline in body weight in the surgery group was –45.0 kg at 2 years, –36.3 kg at 6 years, and –35.0 kg at 12 years.
  • The mean change at 12 years in nonsurgery group 1 was –2.9 kg and the mean change at 12 years in nonsurgery group 2 was 0 kg.
  • Among patients in the surgery group who had T2D at baseline, T2D remitted in 66 of 88 patients (75%) at 2 years, in 54 of 87 patients (62%) at 6 years, and in 43 of 84 patients (51%) at 12 years.
  • The surgery group had higher remission rates and lower incidence rates of hypertension and dyslipidemia than nonsurgery group 1.

Citation:

Adams TD, Davidson LE, Litwin SE, et al. Weight and metabolic outcomes 12 years after gastric bypass. N Engl J Med. 2017;377:1143-1155. doi:10.1056/NEJMoa1700459.

Commentary:

The results of bariatric surgery to reverse and prevent the adverse metabolic consequences of obesity have been nothing less then astonishing. Another recent study showed that bariatric surgery plus intensive medical therapy was far more effective than intensive medical therapy alone in achieving remission of diabetes (an A1c of <6% without medications). In that study, the initial mean A1c was 9.2%, and the mean BMI was 37. At 5 years, A1c less than 6% without medications was met by 5% of patients who received medical therapy alone, as compared with 29% who underwent gastric bypass.1 It is important to recognize that bariatric surgery is not a “set it and forget it” intervention. Post-surgery patients need close follow-up, both for vitamin deficiencies and ongoing behavioral support for maintenance of weight loss and for depression. A review of 28 studies of bariatric surgery showed that suicides and self-harm emergencies occurred more commonly among patients who had undergone bariatric surgery than among persons in the general population or in the control groups of the studies.2 In addition, one of the most intriguing things about the current paper is that not only was a graph showing mean weight loss included, but the graph also included a scatter diagram of the weight loss of each individual in the study. At 12 years, while the mean percent change in weight was approximately 30% in the bariatric surgery group, the range included a few people who gained weight, many with weight loss of 5-15%, and some with 50-60% weight loss. This suggests that some combination of individual variability along with sustained behavioral effort is important post-surgically, just as it is without surgery. —Neil Skolnik, MD

  1. Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery versus intensive medical therapy for diabetes—5-year outcomes. N Engl J Med. 2017;376:641-651. doi:10.1056/NEJMoa1600869.
  2. Peterhänsel C, Petroff D, Klinitzke G, Kersting A, Wagner B. Risk of completed suicide after bariatric surgery: a systematic review. Obes Rev. 2013;14:369-82. doi:10.1111/obr.12014.