Clinical Management of Type 2 Diabetes Mellitus after Bariatric Surgery

The Role of Laboratory Testing in Differentiating Type 1 Diabetes from Type 2 Diabetes in Patients Undergoing Bariatric Surgery

BACKGROUND

It may be difficult to distinguish between adults with type 1 diabetes and type 2 diabetes by clinical assessment. In patients undergoing bariatric surgery, it is critical to correctly classify diabetes subtype to prevent adverse perioperative outcomes including diabetic ketoacidosis. This study aimed to determine whether testing for C-peptide and islet cell antibodies during preoperative evaluation for bariatric surgery could improve the classification of type 1 versus type 2 diabetes compared to clinical assessment alone.

METHODS

This is a retrospective analysis of the Improving Diabetes through Lifestyle and Surgery trial, which randomized patients with clinically diagnosed type 2 diabetes and BMI 30-40 kg/m² to medical weight loss or bariatric surgery; one participant was discovered to have type 1 diabetes after experiencing postoperative diabetic ketoacidosis. Using blood samples collected prior to study interventions, we measured islet cell antibodies and fasting/meal-stimulated C-peptide in all participants.

RESULTS

The participant with type 1 diabetes was similar to the 11 participants with type 2 diabetes in age at diagnosis, adiposity, and glycemic control but had the lowest C-peptide levels. Among insulin-treated participants, fasting and stimulated C-peptide correlated strongly with the C-peptide area-under-the-curve on mixed meal tolerance testing (R = 0.86 and 0.88, respectively). Three participants, including the one with type 1 diabetes, were islet cell antibody positive.

CONCLUSIONS

Clinical characteristics did not correctly identify type 1 diabetes in this study. Preoperative C-peptide testing may improve diabetes classification in patients undergoing bariatric surgery; further research is needed to define the optimal C-peptide thresholds.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations

BACKGROUND

During the last two decades, an increasing number of bariatric surgical procedures have been performed worldwide. There is no consensus regarding optimal perioperative care in bariatric surgery. This review aims to present such a consensus and to provide graded recommendations for elements in an evidence-based "enhanced" perioperative protocol.

METHODS

The English-language literature between January 1966 and January 2015 was searched, with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded. After critical appraisal of these studies, the group of authors reached a consensus recommendation.

RESULTS

Although for some elements, recommendations are extrapolated from non-bariatric settings (mainly colorectal), most recommendations are based on good-quality trials or meta-analyses of good-quality trials.

CONCLUSIONS

A comprehensive evidence-based consensus was reached and is presented in this review by the enhanced recovery after surgery (ERAS) Society. The guidelines were endorsed by the International Association for Surgical Metabolism and Nutrition (IASMEN) and based on the evidence available in the literature for each of the elements of the multimodal perioperative care pathway for patients undergoing bariatric surgery.

Integrating medical and surgical therapies to optimize the outcomes of type 2 diabetes

Modern treatment of type 2 diabetes must rely on therapy individualization. Morbid obesity confers an independent excess of risk to diabetes. In these individuals metabolic surgery is an opportunity the physician should consider, especially at the time of the diabetes diagnosis, because of its efficacy and long-term effects. In addition to the possible remission of diabetes, bariatric surgery is also associated with reduced risk of micro- and macrovascular complications. A multidisciplinary team approach is necessary to maximize the beneficial effects and minimize the adverse events of metabolic surgery and to ensure proper follow-up based on the residual possibility of developing complications. In this regard, a consensus on definition of remission must be reached to define the residual risk after antidiabetic drug withdrawal. Finally, randomized clinical trials are deemed necessary to establish the risk-to-benefit profile of glucose-lowering agents for those patients who have remained diabetic or experience a disease relapse.