Undiagnosed Hyperglycemia Is a Potential Long-term Risk in Metabolic Surgery Patients: 7 Years Follow-up Study

Diabetes is considered to be a surgically correctable illness. As glycemic control begins soon after surgery, the cessation of anti-diabetic medications is early. Patients believe that their diabetes has been "cured" and the need for blood sugar monitoring is forgotten, leading to undiagnosed hyperglycemia and risk of diabetes-related complications.

To study the effect of bariatric surgery on long-term glycemic control and identify the patients with undiagnosed hyperglycemia.

All patients with type 2 diabetes who underwent bariatric surgery at our center from January 2012 to December 2013 were included in the study. For each patient, demographic, preoperative, and postoperative data were retrospectively reviewed.

Out of the total 119 patients with diabetes, 91 patients underwent sleeve gastrectomy and 28 underwent Roux-en-Y gastric bypass. Diabetes status at 7 years of follow-up was possible in 53 (44.5%) patients: 44 (48.4%) in SG and 9 (32.2%) in RYGB groups. Overall, complete remission at 7 years was seen in 17 (32.1%) patients and partial remission in 12 (22.6%) patients. Amongst non-remitters (n = 24, 45.3%), 7 (13.2%) patients were on medications with good glycemic control (A1C < 6.5) while 8 (15.1%) patients had poor control (A1C > 6.5) despite ongoing medications. Additionally, 9 (17%) patients had poor glycemic control (A1C > 6.5) and were not receiving any anti-diabetic medications. Patients in whom follow-up A1C was unavailable and their diabetes status remain unknown were 66 (55.5%) at 7 years.

Our study clearly demonstrates high risk of undiagnosed hyperglycemia. Regular long-term follow-up in diabetic patients is even more desirable than amongst patients undergoing bariatric surgery for weight loss alone. Graphical abstract.