Background: Twenty-six percent of patients with extreme obesity have Type 2 Diabetes Mellitus (T2DM) constituting one of the major indications for weight loss. Remission of T2DM occurs with some frequency following Bariatric surgery.Guidelines in defining T2DM using fasting blood glucose(FBG) have implications for how we define remission post operatively. Preoperative status regarding use of insulin may predict who will go into remission postoperatively.
Methods: A retrospective review of consecutive Bariatric patients at least one year post surgery (n=1370)was performed. Preoperative classification of the 1370 patients showed FBG levels ≤100, not diabetic (50.9%), 101-125, pre-diabetic (22.3%), ≥ 126, diabetic (26.7%).Patients had the following procedures: Gastric Bypass(95%)and Adjustable Gastric Band(4.6%). Mean age of diabetics vs. non-diabetics, was (48.6(9.2 SD) vs. 42.9(10.5 SD); p<0.00), weight(310.4(64.6 SD) vs. 291.2(56.9 SD); NS), BMI (50.5(8.7 SD) vs. 48.5(8.3 SD); p<0.02), FBG(146.6 (57.5 SD)vs.89.1(8.4 SD); p<0.00),HbA1c (7.4(1.6 SD)vs.5.4(0.4 SD);p<0.00), percent female (73.5%, 85.6%; p<0.00), respectively.
Results: Patients tested at regular intervals from 1 - 36 months after surgery are in remission when FBG was ≤ 100mg/dl. Patients with FBG of 101 - 125mg/dl are considered to have remitted to pre-diabetes and patient's ≥ 126mg/dl are considered still diabetic. Of the patients not on insulin preoperatively (n=291), 61.9% (n=180) are in remission, 14.1% (n=41) are pre-diabetic and 22.0% (n=64) remain diabetic. Of patients on insulin preoperatively (n=75), 28.0% (n=21) are in remission, 22.7% (n=17) are pre-diabetic and 48.0% (n=36) remain diabetic (p<0.01). Patients who were readmitted for internal hernia, appendectomy or acute cholecystitis, after demonstrating remission of T2DM tended to display marked hyperglycemia which required perioperative treatment. There was no significant difference among safety outcomes for patients on insulin vs. no insulin.
Conclusion: Outcomes from studies reporting a “cure” of T2DM have been met with skepticism. There are no specific biological markers to measure resolution and cautious definition of remission in those patients who achieve normoglycemia is required. Based on these data,we can expect patients who have not progressed to treatment with insulin to achieve a higher rate of remission and those that are prediabetic to achieve complete remission. Implications for operating on these patients before they convert to insulin dependence are significant.