NATIONAL HARBOR, MD. — Patients with type 2 diabetes who have undergone laparoscopic Roux-en-Y gastric bypass surgery might experience a significant drop in hemoglobin A1c levels to below the cutoff value recommended in guidelines, according to a retrospective study.
The procedure maintained its effect through 3 years of follow-up, during which the patients significantly lowered their use of oral hypoglycemic agents and insulin. More than half (53%) of the gastric bypass patients available for follow-up after 3 years experienced remission of their diabetes.
In comparison, an age- and gender-matched cohort of medically managed patients with type 2 diabetes who did not have surgery developed worsening hemoglobin A1c (HbA1c) levels and significantly increased use of oral hypoglycemic agents and insulin during a similar time frame.
“We feel that bariatric surgery should be considered a first-line treatment option for obese patients with type 2 diabetes,” Dr. Daniel E. Mumme said at the annual meeting of the American Society for Metabolic and Bariatric Surgery.
The study that Dr. Mumme, a surgery resident, presented for his colleagues at Gundersen Lutheran Medical Center, La Crosse, Wis., compared the outcomes of 51 patients with type 2 diabetes who underwent laparoscopic Roux-en-Y gastric bypass at the center during 2001-2005 and 51 medically managed patients with type 2 diabetes identified within a family practice database. Patients in both groups had a mean age of 48 years and 78% were female.
In 48 surgical patients with HbA1c values recorded after 1 year of follow-up, mean HbA1c levels significantly dropped from 7.5% before surgery to 5.8%. The 29 patients who had 3-year follow-up data experienced a significant drop in mean HbA1c levels from 7.8% before surgery to 6.1%. HbA1c levels increased from 7% to 7.8% over a 3-year period in 39 patients of the medically managed comparison cohort. Current treatment guidelines of the American Diabetes Association recommend HbA1c levels below 7%.
Data from a study investigating the association of HbA1c with cardiovascular disease and mortality in adults showed that a percentage point increase in HbA1c was associated with a 20%-30% increase in cardiovascular events or total mortality (Ann. Intern. Med. 2004;141:413-20). In another study, each percentage point drop in HbA1c was associated with a 37% decline in the risk of microvascular complications (BMJ 2000;321:405-12).
In the current study, the surgical patients lost a mean of 103 pounds, or 68% of their excess weight, at 1 year. The body mass index (BMI) of surgical patients dropped from a mean of 48 kg/m
In surgical patients, the use of oral hypoglycemic agents significantly declined from 77% at baseline to 18% at 1 year and 22% at 3 years. In comparison, oral hypoglycemic use in conventionally treated patients rose from 67% at baseline to 82% at 1 year, remaining stable to 3 years. In both groups, insulin use followed the same trends as oral hypoglycemic agents.
At 3 years, 26% of gastric bypass patients used oral hypoglycemic agents and/or insulin, compared with 82% of conventionally treated patients. Remission of diabetes (defined as an HbA1c less than 6% and off diabetic medications) occurred at 1 year in 59% of surgical patients and in 35% of conventionally treated patients.
Of the 51 surgical cohort patients, the 31 who had gone into remission during the 3 years of follow-up had had diabetes for a mean of 4.1 years. That was significantly shorter than the mean duration of disease for the 20 patients who never remitted (7.9 years). Overall, surgical patients had a slightly longer mean duration of diabetes than did nonsurgical patients, said Dr. Mumme, who had no disclosures to make for himself or his coinvestigators.