A new case study cautioned against promoting gastric bypass surgery as a “cure” for diabetes at the AACE 19th Annual Meeting & Clinical Congress in Boston. The study cited that normal hemoglobin A1C (HbA1C) and fasting blood glucose (FBG) were insufficient criteria for such a determination.
Gastric bypass surgery is increasingly receiving attention as a potential “cure” for type 2 diabetes mellitus. Mechanisms of action are not completely understood, but include improvement in insulin resistance and insulin secretion, likely mediated by the action of incretins and other hormonal factors. Surgical outcome reports rely on FBG and HbA1C as criteria for “cure.”
“We present a case where these criteria were present, but did not support remission of diabetes on further evaluation,” Anna L. Marina, MD, a primary author of the case study said. “While results of the procedure certainly improved diabetes outcomes, we don’t feel that it can yet be called a cure.”
In the study, a 55-year-old male with BMI of 45.2 kg/m2 and 7-year history of type 2 diabetes underwent Roux-en-Y gastric bypass (RYGB). Immediately after surgery, insulin requirement decreased from 100 to 30 units daily. Four months after surgery, with weight loss of over 100 pounds, insulin was discontinued. Based on published surgical criteria, the patient’s FBG and HbA1C were indicative of complete remission of type 2 diabetes.
However, diabetes could not be considered cured. Continuous glucose monitoring clearly documented spikes in blood glucose above 200 mg/dl after meals. Therapy was required to reduce postprandial hyperglycemia.
This observation is consistent with very recently presented data by Roslin et al1, who performed a glucose tolerance test in 38 subjects more than 6 months after RYGB. Six patients had diagnosed diabetes before surgery but were not on any prescribed glycemic modifying medications post-op. Five out of the six had normal fasting glucoses and required a glucose tolerance test to show that diabetes was not “cured.”
“HbA1C and fasting blood glucose are not sufficient criteria to establish a type 2 diabetes “cure” after gastric bypass surgery,” Dr. Marina said. “Measurement of postprandial blood glucoses or even continuous glucose monitoring should be considered postoperatively to provide a clear assessment of glycemic status specific to gastric bypass surgery effects in those with established type 2 diabetes.”
1 Roslin M, et al “Abnormal glucose tolerance testing following gastric bypass” Surg Obesity Related Dis 2009; 5(3 Suppl): Abstract PL-205.
American Association of Clinical Endocrinologists (AACE)