Diagnosis of diabetes remission after bariatic surgery may be jeopardized by remission criteria and previous hypoglycemic treatment.

BACKGROUND: Controversy exists regarding type 2 diabetes (T2D) remission rates after bariatric surgery (BS) due to heterogeneity in its definition and patients' baseline features. We evaluate T2D remission using recent criteria, according to preoperative characteristics and insulin therapy (IT).

METHODS: We performed a retrospective study from a cohort of 657 BS from a single center (2006-2011), of which 141 (57.4 % women) had T2D. We evaluated anthropometric and glucose metabolism parameters before surgery and at 1-year follow-up. T2D remission was defined according to 2009 consensus criteria: HbA1c <6%, fasting glucose (FG) <100 mg/dL, and absence of pharmacologic treatment. We analyzed diabetes remission according to previous treatment.

RESULTS: Preoperative characteristic were (mean ± SD): age 53.9 ± 9.8 years, BMI 43.7 ± 5.6 kg/m2, T2D duration 7.4 ± 7.6 years, FG 160.0 ± 54.6 mg/dL, HbA1c 7.6 ± 1.6%. Fifty-six (39.7%) individuals had IT. At 1-year follow-up, 74 patients (52.5%) had diabetes remission. Percentage weight loss (%WL) and percentage excess weight loss (%EWL) were associated to remission (35.5 ± 8.1 vs. 30.2 ± 9.5 %, p = 0.001; 73.6 ± 18.4 vs. 66.3 ± 22.8%, p = 0.037, respectively). Duration of diabetes, age, and female sex were associated to nonremission: 10.3 ± 9.4 vs. 4.7 ± 3.8 years, p < 0.001; 55.1 ± 9.3 vs. 51.2 ± 9.9 years, p = 0.017; 58.9 vs. 33.3%, p = 0.004, respectively. Prior treatment revealed differences in remission rates: 67.1 % in case of oral therapy (OT) vs. 30.4% in IT, p < 0.001. OR for T2D remission in patients with previous IT, compared to those with only OT, were 0.157-0.327 (p < 0.05), adjusting by different models.

CONCLUSIONS: Consensus criteria reveal lower T2D remission rates after BS than previously reported. Prior insulin use is a main setback for remission.