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Gastric Bypass Benefits Outweigh Risks after Two Years?

May 29, 2015

Deficiencies in iron, calcium and vitamin D were more common in the gastric bypass group….

A new international study found that two years post-surgery, those who had gastric bypass have better diabetes control, but they also had higher risks of infection and fractures.


Researchers recruited 120 obese patients with type 2 diabetes at three teaching hospitals in the U.S. and one in Taiwan between 2008 and 2011. Participants, aged 30 to 67 years, were randomly divided into one of two groups, lifestyle and medical management (“lifestyle group”) or lifestyle and medical management with gastric bypass (“bypass group”).

Both groups were instructed to record their daily intake, increase their exercise goal of 325 minutes/week and weigh themselves while meeting regularly with a nurse or dietitian. They also met with an endocrinologist as needed to assess the need for medication management for glucose control, cholesterol and blood pressure. Weight-loss surgery was only within the bypass group.

Results of the Diabetes Surgery Study, which is still ongoing, found that 24 patients in the bypass group had lower HbA1c levels, lower LDL and lower BP two years post-surgery, compared to eight patients in the lifestyle group. Deficiencies in iron, calcium and vitamin D were more common in the bypass group. When comparing infections and fractures in both groups there were eight infections in the bypass group compared to four in the lifestyle group and five fractures in the bypass group compared to one in the comparison group.

“I assume nutritional deficiencies are likely to be an even greater problem in general practice,” said Markku Peltonen of the National Institute for Health and Welfare in Finland in an accompanying editorial. Carefully taking nutritional supplements and maintaining physical activity reduces the risk of adverse events. “We are still not sure which are the best patients with diabetes to consider for gastric bypass or other bariatric surgery,” he said.

Further research to identify which patients are the best candidates for surgery is necessary to minimize the risks of infection and bone fractures while also improving diabetes control.

Practice Pearls:

  • Infection and bone fractures are risks to consider in diabetic patients seeking gastric bypass for improvement in diabetes control.
  • Two years post-surgery, 24 patients in the bypass group achieved decreased HbA1c levels, LDL and BP compared to 8 in the lifestyle group.
  • Nutritional supplementation is important in the post-surgical monitoring diabetic patients undergoing bypass surgery.

Prof Sayeed Ikramuddin. Roux-en-Y gastric bypass for diabetes (the Diabetes Surgery Study): 2-year outcomes of a 5-year, randomised, controlled trial. The Lancet Diabetes & Endocrinology, pub online May 12, 2015. http://dx.doi.org/10.1016/S2213-8587(15)00089-3