Patients with type 2 diabetes who underwent Roux-en-Y gastric bypass (RYGB) surgery experienced higher rates of diabetes remission, improved glycemic control, greater weight loss, and fewer diabetes relapse events, compared with those who had sleeve gastrectomy, according to findings from nearly 10,000 patients.
“Remission of type 2 diabetes is common after bariatric surgery and may reduce risk for subsequent microvascular and macrovascular disease,” but it is not clear which of the two most common procedures, RYGB or sleeve gastrectomy, has better long-term diabetes and weight outcomes, wrote Kathleen M. McTigue, MD, of the University of Pittsburgh, and colleagues in JAMA Surgery.
To examine the effectiveness of the two procedures, the researchers identified 9,710 adults with type 2 diabetes who were part of the National Patient-Centered Clinical Research Network Bariatric Study. They compared diabetes outcomes for up to 5 years after surgery for 6,233 patients who underwent RYGB and 3,477 who underwent sleeve gastrectomy. The average age of the patients was 50 years, and 73% were women. The average preoperative body mass index was 49 kg/m2.
Overall, 6,141 patients experienced diabetes remission. The estimated adjusted cumulative remission rates for the RYGB and sleeve gastrectomy groups after 1 year were 59% and 56%, respectively, and after 5 years were 86% and 84%.
Weight loss was significantly greater in RYGB patients, compared with those who had the sleeve gastrectomy, with average differences in percentage points of 6.3 at 1 year and 8.1 at year 5. RYGB patients also showed significantly better long-term glycemic control, compared with sleeve gastrectomy patients. At 5 years, hemoglobin A1c levels were 0.80 percentage points below baseline in the RYGB group, and 0.35 percentage points below baseline in the sleeve gastrectomy group.
In addition, after 1 year, diabetes relapse rates in the RYGB and sleeve gastrectomy groups were 8% and 11%, respectively, and 33% and 42% after 5 years.
The findings were limited by several factors, including the observational design of the study and the potential for confounding and coding inaccuracies, the researchers noted, adding that future studies should address the impact of weight loss on diabetes remission and relapse in bariatric surgery patients.
They also noted that their results were in contrast to findings in previous studies that established no significant differences in outcomes between the procedures, but emphasized that most previous studies were smaller and controlled and that outcome differences may be greater in clinical practice.
“For patients, clinicians, and policy makers to make informed decisions about which procedure is best suited to patients’ personal situations, additional data are needed to understand the adverse event profile of the procedures, as well as patient values regarding procedure choice and the role of surgery relative to other aspects of lifelong weight management,” they concluded.
In an accompanying commentary, Natalie Liu, MD, and Luke M. Funk, MD, of the department of surgery, University of Wisconsin–Madison, said the analysis made an important contribution to the existing literature, despite its limitations.
“It included long-term electronic health record data from a large cohort of U.S. patients who had bariatric surgery in a real-world setting,” they wrote, adding that, although the remission rates were high, the relapse rate in both treatment groups deserved further study.
Dr. Liu and Dr. Funk emphasized that the overall high remission rates for either surgery, compared with lifestyle interventions, suggest the need for continued advocacy for better insurance coverage of, and access to, bariatric surgery procedures for patients with type 2 diabetes, notably those with class 1 obesity.
The study was conducted using the National Patient-Centered Clinical Research Network, which was funded by the Patient-Centered Outcomes Research Institute. Dr. McTigue and Dr. Liu had reported no conflicts of interest. Dr. Funk disclosed a Veterans Affairs Health Services Research & Development Career Development Award, and grants from the VA, National Institutes of Health, and American College of Surgeons.
SOURCES: McTigue KM et al. JAMA Surg. 2020 Mar 4. doi: 10.1001/jamasurg.2020.0087; Lui N, Funk LM. JAMA Surg. 2020 Mar 4. doi: 10.1001/jamasurg.2020.0088.