Metabolic bariatric surgery provided superior improvements in glycemic control and weight loss compared with medical and lifestyle therapy in patients with type 2 diabetes, with consistent benefits across levels of social deprivation, according to an analysis of the Alliance of Randomized Trials of Medicine vs Metabolic Surgery in Type 2 Diabetes Consortium of randomized trials.
"Social determinants of health can affect metabolic health," the researchers remarked. However, they noted, "This study did not detect statistically significant differences in the comparative advantage of surgery over medical therapy by [Area Deprivation Index]."
These findings—which may have implications for referral decisions, health equity, and diabetes management strategies—were published in the Annals of Internal Medicine by lead study author Mary Elizabeth Patti, MD, of Joslin Diabetes Center and Harvard Medical School, Boston, and colleagues.
Study Details
The study analyzed the effect modification of baseline Area Deprivation Index (ADI)—a metric of social vulnerability—on longitudinal outcomes between randomized treatment groups using linear mixed-effects models. It was conducted at four US academic centers and included 258 patients with type 2 diabetes who were enrolled in four randomized controlled trials of surgical vs medical management, along with a longitudinal observational follow-up study.
At randomization, ADI was linked to ZIP code data. Weight loss and hemoglobin A1c (HbA1c) levels were assessed at the end of the active intervention period (7 to 12 years).
Following adjustment for study site and stratification by high vs low ADI, baseline characteristics were reported to be well balanced between the surgical and medical therapy groups.
Key Findings
Surgery was more effective than medical therapy in lowering HbA1c levels among patients with both high ADI (net difference: −1%) and low ADI (net difference: −1%). It also led to greater weight loss across ADI levels, with respective net differences of −11% and −13%. The interaction between ADI and intervention group was not statistically significant for either HbA1c or weight loss, according to the researchers.
Study limitations included a small sample size and that the parent trials were not designed to address effect modification by ADI.
Disclosure: For full disclosures of the study authors, visit acpjournals.org.
Source: Annals of Internal Medicine
