News

Gastric bypass helps poorly controlled type 2 diabetes

View on the News

Bariatric surgery for millions?

Proponents of bariatric surgery have proposed extending the treatment to diabetic patients with BMIs as low as 27. Since an estimated 4% of the U.S. population has low-grade obesity and diabetes, any proposal to treat such a large number of patients surgically must be carefully evaluated.

In addition, the long-term goal of such surgery isn’t simply weight loss; it is to reduce the microvascular and macrovascular complications of diabetes. It is not yet known whether the short-term success of bariatric surgery impacts this ultimate goal.

Moreover, as many as 50% of bariatric surgery patients who initially experience remission of diabetes are reported to later develop a recurrence, and the ramifications of such a temporary remission are not yet known, either.

Bruce M. Wolfe, M.D., and Jonathan Q. Purnell, M.D., are at Oregon Health and Science University, Portland. Steven H. Belle, Ph.D., is in the department of epidemiology at the University of Pittsburgh Graduate School of Public Health. They reported no financial conflicts of interest. These remarks were taken from their editorial accompanying the two reports on bariatric surgery (JAMA 2013;309:2274-5).


 

FROM JAMA

In patients with mild to moderate obesity and poorly controlled type 2 diabetes, adding Roux-en-Y gastric bypass surgery to intensive lifestyle and medical management more than doubles the likelihood of achieving weight-loss and metabolic goals within 1 year, according to the results of a randomized trial reported in the June 5 issue of JAMA.

However, this potential benefit must be weighed against what appears to be a moderate risk of serious adverse events, even when the procedure is done by experienced medical teams, said Dr. Sayeed Ikramuddin of the department of surgery, University of Minnesota, Minneapolis, and his associates.

In addition, the permanence of weight loss and metabolic results following the first 1-2 years after the procedure remains uncertain, as do long-term adverse events, because so few studies have adequately followed patients past that point, the investigators wrote.

Dr. Melinda A. Maggard-Gibbons

Dr. Ikramuddin and his colleagues drew these conclusions from their randomized trial of 120 patients with mild to moderate obesity (body mass index, 30.0-39.9 kg/m2) whose type 2 diabetes was poorly controlled on standard medical therapy.

In a separate report in the same issue of JAMA, Dr. Melinda Maggard-Gibbons of the University of California, Los Angeles, and her associates reported their findings from a systematic review of the literature regarding all types of bariatric surgery in similar patients with mild obesity (BMI, 30-35). They found that there still is not sufficient evidence to determine whether bariatric surgery is warranted in this patient population because of the lack of long-term data on safety and efficacy. They identified only four studies with a follow-up of more than 2 years, and those had small sample sizes or poor methodology that "preclude definitive conclusions."

Thus, neither of these investigations can support or refute the suggestion by some proponents that bariatric surgery should be extended to diabetic patients with low-grade obesity to improve their glycemic control.

In their prospective, unblinded clinical trial, Dr. Ikramuddin and his associates offered a free, intensive lifestyle and medical-therapy weight control program to the 120 study subjects at one academic medical center in Minnesota, one in New York, and two in Taiwan over a 3-year period. All patients were between 30 and 67 years of age and had hemoglobin A1c (HbA1c) levels of 8% or higher (mean, 9.6%); the average duration of diabetes was 9 years.

The program included daily weigh-ins and detailed diaries of eating and exercise, with caloric intake goals of 1,200-1,800 kcal/day and moderate physical activity for at least 325 min/week to achieve a weight loss of 1-2 pounds/week. The study subjects met regularly with trained interventionists to discuss weight management and to enhance adherence.

Patients could add orlistat or, until it was withdrawn from the market, sibutramine for weight control. Medications for glycemic control were added as necessary, as were aspirin therapy and medications to control cholesterol levels and blood pressure.

Half of the study subjects were then randomly assigned to undergo laparoscopic Roux-en-Y gastric bypass. This group was given multivitamin and mineral supplements.

The endpoint of the study was a triple outcome endorsed by the American Diabetes Association: an HbA1c level of less than 7%, a low-density lipoprotein (LDL) cholesterol level of less than 100 mg/dL, and a systolic blood pressure of less than 130 mm Hg at 1-year follow-up.

A total of 28 patients (49%) in the gastric bypass group achieved this end point, compared with only 11 (19%) in the lifestyle/medical management group, Dr. Ikramuddin and his colleagues reported (JAMA 2013;309:2240-49).

Of these three components of the combined endpoint, only HbA1c level showed a significant difference between the two study groups: 43 (75%) of the surgery group achieved an HbA1c level under 7%, compared with just 18 (32%) of the lifestyle/medical management group.

The difference in outcomes between the two groups was attributed chiefly to their difference in weight loss. The mean loss at 1 year was 26% of baseline weight after gastric bypass, compared with 8% with the intensive lifestyle/medication program.

Patients in the surgery group continued to lose weight throughout the year of follow-up, while those in the other group tended to lose weight during the first 6 months and plateau after that.

On average, at 1 year the patients in the surgery group required three fewer medications than did those in the other group to manage glycemia, dyslipidemia, and hypertension.

However, patients who underwent gastric bypass had 50% more serious adverse events and 55% more nonserious adverse events than did those who did not. "All surgeons performing gastric bypass in this study were experts; thus the occurrence of serious complications must be factored into the design of larger trials of effectiveness for patients with moderate obesity," Dr. Ikramuddin and his associates said.

Pages

Recommended Reading

CABG Survival Beats PCI in Big U.S. Dataset
MDedge Surgery
Obesity Paradox Also Applies to CABG Patients
MDedge Surgery
U.S. Medicare Leg Amputations Down From 2000 to 2008
MDedge Surgery
Equally Low Thrombosis Seen With Zotarolimus-, Sirolimus-Eluting Stents
MDedge Surgery
FAME 2 Favorable PCI Results Driven by Revascularization
MDedge Surgery
Withholding Warfarin After GI Bleed Raises Risk of Thrombosis, Death
MDedge Surgery
FREEDOM: CABG Shows Excellent Cost Effectiveness
MDedge Surgery
Bariatric surgery cut vascular events in diabetes
MDedge Surgery
Breast cancer: Cardiac risk increases with radiation dose to heart
MDedge Surgery