Gastric bypass reduces [HbA.sub.1c] levels in diabetes.

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 [A.sub.1c] 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 undergo surgery developed worsening hemoglobin [A.sub.1c]([HbA.sub.1c]) levels and significantly increased use of oral hypoglycemic agents and insulin during a similar time frame.

"Based on our findings, 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 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 Rouxen-Y gastric bypass at the center during 2001-2005 and 51 medically managed patients with type 2 diabetes who were identified within a family practice database. Patients in both groups had a mean age of 48 years, and 78% were female.

Among 48 surgical patients with [HbA.sub.1c] values recorded after 1 year of follow-up, mean [HbA.sub.1c] levels significantly dropped from 7.5% before surgery to 5.8%. The 29 patients who had 3-year follow-up data had a significant drop in mean [HbA.sub.1c] levels from 7.8% before surgery to 6.1%. [HbA.sub.1c] levels increased from 7% to 7.8% over a 3-year period in 39 patients of the medically managed comparison cohort. The current treatment guidelines of the American Diabetes Association recommend lowering [HbA.sub.1c] levels below 7%.

Data from a study of the association of [HbA.sub.1c] with cardiovascular disease and mortality in adults showed that a percentage point increase in [HbA.sub.1c] 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 [HbA.sub.1c] was tied to 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.sup.2] before surgery to a BMI of 31 after 1 year. Nonsurgical patients initially had a mean BMI of 45.

Among 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 [HbA.sub.1c] 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 patients, the 31 who had gone into remission at some point during the 3 years of follow-up had had diabetes for a mean of 4.1 years--shorter than the mean duration for the 20 patients who never remitted (7.9 years). Overall, surgical patients had a slightly longer mean duration of diabetes than did non surgical patients, said Dr. Mumme, who did not have any disclosures to make for himself or his coinvestigators.

BY JEFF EVANS

Senior Writer