Bariatric surgery appears most effective in treating type 2 diabetes
Roux-en-Y gastric bypass results in greater weight loss and glycemic control, as well as improved cardiometabolic health and quality of life, in patients with obesity and type 2 diabetes vs. gastric banding or lifestyle interventions, according to two studies published in JAMA Surgery.
Although certain challenges exist to completing large randomized clinical trials for treatment of type 2 diabetes and obesity, including recruiting and assigning patients to surgical vs. non-surgical interventions, current findings offer a foundation to best help patients at this time, according to researchers.
Allison B. Goldfine
“Greater magnitude metabolic improvements following Roux-en-Y gastric bypass (RYGB) have the potential to reduce cardiovascular morbidity and mortality as seen in nonrandomized studies, which may help inform therapeutic decisions for diabetes and weight-loss strategies in obese patients with type 2 diabetes until larger randomized trials are performed,” study researcher Allison B. Goldfine, MD, of the research division at Joslin Diabetes Center, Harvard Medical School, told Endocrine Today.
Results seen with RYGB
In the 1-year pragmatic randomized Surgery or Lifestyle With Intensive Medical Management in the Treatment of Type 2 Diabetes (SLIMM-T2D) trial, Florencia Halperin, MD, of the division of endocrinology, diabetes and hypertension, Brigham and Women’s Hospital, Harvard Medical School, and a team of researchers, including Goldfine, looked at 38 patients (aged 21-65 years, BMI 30-42, HbA1c ≥6.5%). Participants all had a type 2 diabetes diagnoses for at least 1 year and were assigned antihyperglycemic medications.
Patients were evenly assigned to RYGB surgery or the intensive diabetes medical and weight management program Weight Achievement and Intensive Treatment (Why WAIT), which included 12 weekly group sessions (lifestyle, medical and educational) with monthly follow-up.
The researchers found that more patients achieved the goal improvements of HbA1c ≤6.5% and fasting glucose <126 mg/dL with RYGB compared with Why WAIT (58% vs. 16%; P=.03) at 1 year. Greater improvements were also observed in waist circumference, fat mass, lean mass, blood pressure, triglyceride levels, HDL cholesterol and CV risk scores with RYGB vs. Why WAIT when the study concluded.
Progress from baseline in the moderately low self-reported quality-of-life scores (reflected by Short Form-36 total, physical and mental health) and high health status scores for Problem Areas in Diabetes did not differ significantly between groups. However, patient scores for Impact of Weight on Quality of Life–Lite improved more with RYGB and were associated with greater weight loss.
“Our findings, taken in context of additional recent randomized studies that are relatively small in number of participants and short in duration of follow-up, which also show greater magnitude of metabolic improvement with gastric bypass, together with the longer duration observational studies, suggest surgery may be an appropriate option for diabetes and weight management in patients in whom surgical risk is appropriately low,” Goldfine said.
Trials feasible, looking forward
Similar findings came from a randomized year-long trial by Anita P. Courcoulas, MD, MPH, of the department of surgery, University of Pittsburgh Medical Center, and colleagues, which followed 61 patients (aged 25-55 years, BMI 30-40, HbA1c=7.9%) with type 2 diabetes assigned to bariatric surgery or a weight-loss program.
Anita P. Courcoulas
The researchers evaluated participants in three cohorts — RGYB (n=20), laparoscopic adjustable gastric banding (LAGB; n=21) and intensive lifestyle weight-loss intervention (LWLI; n=20) — to determine weight loss and improvements in glycemic control and gauge study feasibility. The retention rates were 90% for RGYB, 86% for LAGB and 70% for LWLI.
“Randomized trials to compare surgical and nonsurgical treatments for type 2 diabetes in the setting of obesity are very difficult to conduct, and the results of several small studies such as this one may need to be combined to answer important questions about comparative effectiveness,” Courcoulas told Endocrine Today.
From baseline, patients who underwent RYGB achieved the greatest average weight loss (27%; 95% CI, 30.8-23.3) compared with LAGB (17.3%; 95% CI, 21.1-13.5) and LWLI (10.2%; 95% CI, 14.8-5.61). There were, however, multiple imputations for missing data among the intention-to-treat groups.
In the RYGB group, 50% of patients had partial remission of type 2 diabetes and 17% had complete remission, whereas in the LAGB group, 27% had partial remission and 23% had complete remission (P<.001 and P=.047 between groups for partial and complete remission). The LWLI group experienced no remission. Patients in both surgical groups also significantly reduced their use of antidiabetic medication.
“Surgical treatments are safe and effective in the short term to treat type 2 diabetes and should be considered for those with disease that is difficult to treat or who have failed medical treatment,” Courcoulas said. “Longer-term results from this and other randomized trials are coming in the next 1 to 2 years that will address the longer-term safety and durability of these surgical and lifestyle and medical treatments.” — by Allegra Tiver
Disclosure: Please see the studies for a full list of researchers’ financial disclosures and study funding.