Among adults with obesity and type 2 diabetes undergoing Roux-en-Y gastric bypass, 74% experienced diabetes remission after 1 year, whereas 27% had relapsed by 5 years, suggesting more careful follow-up is needed, according to findings published in Diabetologia.
In an analysis of more than 1,100 adults treated at hospitals in northern Denmark between 2006 and 2015, researchers also observed that diabetes remission at 1 year was associated with a 57% reduced risk for microvascular complications and a 24% reduced risk for macrovascular complications during follow-up.
Lene Ring Madsen
“Our results add to the evidence that patients with obesity and type 2 diabetes should be offered bariatric surgery early on in the course of their disease while there is still a great chance of diabetes remission,” Lene Ring Madsen, MD, PhD, of the department of endocrinology and internal medicine at Aarhus University Hospital, Denmark, told Endocrine Today. “Furthermore, bariatric surgery lowers the risk of microvascular complications. Overall, the surgery is safe. Therefore, we as doctors should bear this kind of treatment for patients with obesity and type 2 diabetes in mind as a part of our toolbox in treatment of type 2 diabetes. Furthermore, our study shows that type 2 diabetes following Roux-en-Y gastric bypass is dynamic; therefore, patients treated by surgery should comply to regular checkups.”
In a population-based observational study, Madsen and colleagues analyzed data from 1,111 adults with a BMI of at least 35 kg/m² and type 2 diabetes who underwent Roux-en-Y gastric bypass (median age, 47 years; 63.5% women; median diabetes duration, 3.6 years; median follow-up, 5.3 years) and 1,074 matched controls with type 2 diabetes who did not undergo bariatric surgery (median follow-up, 5.2 years). Researchers defined diabetes remission as an HbA1c of less than 6.5% and the use of no glucose-lowering drugs at each 6-month follow-up, or metformin monotherapy with an HbA1c of less than 6%. Diabetes relapse was defined as occurrence of an HbA1c of at least 6.5% or a new prescription for a glucose-lowering drug after initial discontinuation. Study outcomes included microvascular and macrovascular complications. Researchers used Poisson regression analysis to assess predictors for not achieving diabetes remission in the Roux-en-Y cohort, as well as the annual prevalence of diabetes relapse after 1 year among those who achieved diabetes remission after surgery. Cox proportional hazard regression was used to estimate the risk for microvascular and macrovascular complications after index date for those who underwent surgery vs. controls.
Predictors of remission
Six months after surgery, 65% of adults who underwent Roux-en-Y gastric bypass fulfilled criteria for diabetes remission, with 74% of the gastric bypass group fulfilling criteria at 12 months and 70% of patients fulfilling diabetes remission criteria for every 6-month follow-up visit in the first 5 years. At 5 years, 27% of those who achieved diabetes remission had relapsed, according to researchers. Predictors of not achieving remission included adults aged 50 to 60 years (RR = 0.88; 95% CI, 0.81-0.96) or at least 60 years (RR = 0.83; 95% CI, 0.72-0.97) vs. those younger than 40 years, as well as a diabetes duration of 5 to 8 years (RR = 0.87; 95% CI, 0.79-0.97) or a diabetes duration of at least 8 years (RR = 0.73; 95% CI, 0.62-0.86) vs. a diabetes duration of less than 2 years. Additionally, an HbA1c of at least 7% (RR = 0.81; 95% CI, 0.75-0.88) and the use of glucose-lowering drugs other than metformin (RR = 0.9; 95% CI, 0.81-1) were also associated with not achieving diabetes remission, with insulin use in particular being the strongest predictor (RR = 0.57; 95% CI, 0.48-0.68), according to researchers.
Microvascular, macrovascular complications
During follow-up, incidence rates for any microvascular event were 21.5 per 1,000 person-years in the Roux-en-Y group and 38.7 per 1,000 person-years in the control group, for an incidence rate ratio of 0.56 (95% CI, 0.44-0.7). After adjustment for confounders, researchers found that the Roux-en-Y group had a 47% lower risk for incident microvascular disease vs. controls (HR = 0.53; 95% CI, 0.38-0.73) during follow-up.
Incidence rates for macrovascular complications were 11.7 per 1,000 person-years for the Roux-en-Y group and 15 per 1,000 person-years for the control group, for an incidence rate ratio of 0.78 (95% CI, 0.56-1.09). The HR for macrovascular events for the gastric bypass group was 0.76 compared with controls (95% CI, 0.49-1.18), with results persisting after adjustment for confounders.
When researchers compared patients who underwent surgery who did and did not fulfill diabetes remission criteria at 1 year, microvascular events were 57% lower among those who achieved diabetes remission (HR = 0.43; 95% CI, 0.25-0.72) and macrovascular events were 24% lower (HR = 0.76; 95% CI, 0.4-1.45).
The researchers noted that there is still a “substantial risk” for relapse into type 2 diabetes, which should be accounted for when advising patients and planning postsurgical care.
“Studies with even longer follow-up on diabetes remission and diabetic complications and studies evaluating the long-term chance of diabetes remission following the newer form of bariatric surgery — gastric sleeve — are needed,” Madsen said. – by Regina Schaffer
For more information:
Lene R. Madsen, MD, PhD , can be reached at Aarhus University Hospital, Department of Endocrinology and Internal Medicine, Palle Juul-Jensens Blvd. 99, 8200 Aarhus N, Denmark; email: firstname.lastname@example.org.
Disclosures: Madson reports she is affiliated with the Danish Diabetes Academy, which is funded by the Novo Nordisk Foundation. The A.P. Møller Foundation, the Health Research Fund of Central Denmark and the Novo Nordisk Foundation funded this study.