Type 2 diabetes, cured by weight loss surgery, returns in one-fifth of patients

"The recurrence rate was mainly influenced by a longstanding history of Type 2 diabetes before the surgery," said the study's lead author, Yessica Ramos, MD, an internal medicine resident at Mayo Clinic Arizona in Scottsdale. "This suggests that early surgical intervention in the obese, diabetic population will improve the durability of remission of Type 2 diabetes."

Ramos and her co-investigators studied the medical records of 72 obese patients with Type 2 diabetes who underwent a Roux-en-Y gastric bypass operation between 2000 and 2007 and had at least three years of follow-up visits. Of these, 66 patients (92 percent) had a reversal of their diabetes at some point, the authors reported.

Within three to five years after surgery, however, 14 (21 percent) of the 66 patients experienced a recurrence of their Type 2 diabetes, as documented by bloodwork or restarting use of diabetes medications. The patients who did not have recurrence of diabetes lost more weight initially and maintained a lower mean weight throughout the five years of follow-up, although both groups regained similar amounts of weight. There was no significant association between higher recurrence rate and body mass index before surgery, the authors found.

They did find that the longer the duration of Type 2 diabetes before surgery, the higher the probability of diabetes recurrence. Study patients with more than a five-year duration of Type 2 diabetes before they had bariatric surgery were 3.8 times more likely to have recurrence of type 2 diabetes compared to patients with less than a 5 year history of diabetes.

"Providers and patients need to be aware of this information, to have a better idea of the expected outcome and be able to make an informed decision about pursuing gastric bypass surgery," Ramos said.