Type 2 Diabetes Remission and Control in Overweight and in Mildly Obese Diabetic Patients at Long-Term Follow-Up After Biliopancreatic Diversion

BACKGROUND: In severely obese patients with type 2 diabetes (T2DM), the metabolic benefits after biliopancreatic diversion (BPD) are due to mechanisms independent of weight loss. Therefore, the anti-diabetic effect of BPD in overweight or mildly obese T2DM patients was investigated. METHODS: Ninety T2DM patients with BMI 25-35 underwent BPD and were evaluated 1 and 5 years after the operation (follow-up rate 100 and 83%, respectively). RESULTS: T2DM control (Hb1Ac < 7%) and remission (Hb1Ac < 6 without antidiabetics) was observed in 86.6 and 65% of cases at 1 year and 64.0% and 26.5% at 5 years, respectively. The long-term T2DM remission was predicted by baseline BMI value. Both before BPD and throughout the follow-up period, HOMA values were similar in the metabolically successful and unsuccessful subjects, while C-peptide normalized for FBG value as a marker of beta cell mass and insulin secretion increased progressively only in the former from 1.06 ± 0.64 to 1.44 ± 1.08 mcg/l ml/dl-1 * 100 (p < 0.002). CONCLUSIONS: In T2DM patients with BMI of 25-35, a positive metabolic outcome is less frequent than in their counterparts with morbid obesity. In T2DM overweight patients, in spite of a short-term normalization of FBG and HbA1c levels and a well-sustained increase of insulin sensitivity, a long-term T2DM relapse occurs in the majority of the cases. While the surgically obtained decrease in insulin resistance leads to T2DM control in half of the patients, the increase in insulin secretion is mandatory for T2DM stable remission.