Perioperative management of diabetes in patients undergoing bariatric and metabolic surgery: a narrative review and the Cleveland Clinic practical recommendations.

Bariatric and metabolic surgery is an effective treatment for patients with severe obesity and obesity-related diseases. In patients with type 2 diabetes, it provides marked improvement in glycemic control and even remission of diabetes. In patients with type 1 diabetes, bariatric surgery may offer improvement in insulin sensitivity and other cardiometabolic risk factors, as well as amelioration of the mechanical complications of obesity. Because of these positive outcomes, there are increasing numbers of patients with diabetes who undergo bariatric surgical procedures each year. Prior to surgery, efforts should be made to optimize glycemic control. However, there is no need to delay or withhold bariatric surgery until a specific glycosylated hemoglobin target is reached. Instead, treatment should focus on avoidance of early postoperative hyperglycemia. In general, oral glucose-lowering medications and noninsulin injectables are not favored to control hyperglycemia in the inpatient setting. Hyperglycemia in the hospital is managed with insulin, aiming for perioperative blood glucose concentrations between 80 and 180 mg/dL. Following surgery, substantial changes of the antidiabetic medication regimens are common. Patients should have a clear understanding of the modifications made to their treatment and should be followed closely thereafter. In this review article, we describe practical recommendations for the perioperative management of diabetes in patients with type 2 or type 1 diabetes undergoing bariatric surgery. Specific recommendations are delineated based on the different treatments that are currently available for glycemic control, including oral glucose-lowering medications, noninsulin injectables, and a variety of insulin regimens.

POSTOPERATIVE INSULIN REQUIREMENTS IN BARIATRIC SURGERY.

OBJECTIVE: Though insulin dose reduction months after surgery is a well-studied outcome, there are limited data on immediate postoperative changes. The goals of the present study were to ( 1) To determine peri-operative glycemic control in patients with type 2 diabetes mellitus (DM) on insulin who have undergone Roux-en-Y gastric bypass (RYGB) and ( 2) to compare pre- and postoperative insulin regimens and dosages in these patients. METHODS: A retrospective chart review was conducted on patients with type 2 DM on insulin who underwent RYGB surgery. Blood glucose (BG) levels and insulin doses were compared prior to surgery, on the day of surgery (DOS), and postoperative days (POD) 1 and 2. Subgroup analysis was performed to see if insulin dose was related to glucose control. RESULTS: There were 114 subjects with a mean (SD) age of 52.8 ± 9.8 years, body mass index (BMI) 46.2 ± 8.0 kg/m2, glycated hemoglobin A1c (HbA1c) 8.3% (67 mmol/mol) ± 1.7%, and 66% on insulin plus noninsulin medications and 34% on insulin only. Mean blood glucose (BG) significantly decreased from the DOS (185 ± 43 mg/dL) through POD2 (160 ± 36, P<.0001). The median daily insulin dose significantly decreased from before surgery on usual diet (75 units [36, 116 interquartile range (IQR)]) through POD2 (6 [2, 15 IQR]), P<.0001). The median insulin dose per body weight decreased significantly from before surgery on usual diet (0.58 units/kg [0.35, 0.84 IQR]) through POD2 (0.04 [0.02, 0.11 IQR]), P<.0001). The subgroup with relatively good control experienced a larger percentage reduction in insulin requirements versus subjects with poor control. CONCLUSION: An 87.5% reduction in total daily insulin dose was seen by POD2. This will assist in developing algorithms for insulin titration postbariatric surgery. ABBREVIATIONS: BG = blood glucose DM = diabetes mellitus DOS = day of surgery HbA1c = glycated hemoglobin IQR = interquartile range IV = intravenous NPH = neutral protamine Hagedorn POD = postoperative day RYGB = Roux-en-Y gastric bypass SSRI = sliding scale regular insulin.