Factors affecting relapse of type 2 diabetes after bariatric surgery in Sweden 2007-2015: a registry-based cohort study

Abstract

Background: Although a large proportion of patients with type 2 diabetes (T2DM) who have undergone metabolic surgery experience initial remission some patients later suffer from relapse. While several factors associated with T2D remission are known, less is known about factors that may influence relapse.

Objectives: To identify possible risk factors for T2D relapse in patients who initially experienced remission.

Setting: Nationwide, registry-based study.

Methods: We conducted a nationwide registry-based retrospective cohort study including all adult patients with T2D and body mass index ≥35 kg/m² who received primary metabolic surgery with Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) in Sweden between 2007 and 2015. Patients who achieved complete diabetes remission 2 years after surgery was identified and analyzed. Main outcome measure was postoperative relapse of T2D, defined as reintroduction of diabetes medication.

Results: In total, 2090 patients in complete remission at 2 years after surgery were followed for a median of 5.9 years (interquartile range [IQR] 4.3-7.2 years) after surgery. The cumulative T2D relapse rate was 20.1%. Duration of diabetes (hazard ratio [HR], 1.09; 95% confidence interval [CI], 1.05-1.14; P < .001), preoperative glycosylated hemoglobin A1C (HbA1C) level (HR, 1.01; 95% CI, 1.00-1.02; P = .013), and preoperative insulin treatment (HR, 2.67; 95% CI, 1.84-3.90; P < .001) were associated with higher rates for relapse, while postoperative weight loss (HR, .93; 95% CI, .91-.96; P < .001), and male sex (HR, .65; 95% CI, .46-.91; P = .012) were associated with lower rates.

Conclusion: Longer duration of T2D, higher preoperative HbA1C level, less postoperative weight loss, female sex, and insulin treatment prior to surgery are risk factors for T2D relapse after initial remission.

Keywords: Bariatric surgery; Diabetes; Gastric bypass; Metabolic surgery; Obesity; Relapse; Sleeve gastrectomy; Type 2 diabetes.