Bariatric Surgery and Prevention of Type 2 Diabetes in Swedish Obese Subjects

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By: Lena M.S. Carlsson, M.D., Ph.D., Markku Peltonen, Ph.D., Sofie Ahlin, M.D., Åsa Anveden, M.D., Claude Bouchard, Ph.D., Björn Carlsson, M.D., Ph.D., Peter Jacobson, M.D., Ph.D., Hans Lönroth, M.D., Ph.D., Cristina Maglio, M.D., Ingmar Näslund, M.D., Ph.D., Carlo Pirazzi, M.D., Stefano Romeo, M.D., Ph.D., Kajsa Sjöholm, Ph.D., Elisabeth Sjöström, M.D, Hans Wedel, Ph.D., Per-Arne Svensson, Ph.D., and Lars Sjöström, M.D., Ph.D.*
Released: Thursday, August 23, 2012

BATON ROUGE, LA - The obesity epidemic is spawning an epidemic of type 2 diabetes, a condition associated with serious medical and economic consequences. New approaches for preventing and managing obesity-related diabetes are urgently needed.

Weight loss protects against type 2 diabetes but is hard to maintain with the traditional behavioral modification approach alone. The study to be reported in the New England Journal of Medicine by Carlsson and colleagues examined the effects of bariatric surgery on the prevention of type 2 diabetes.  

The authors included 1658 patients who underwent bariatric surgery and 1771 obese matched controls. None of the participants had diabetes at baseline. Patients in the bariatric-surgery group underwent three types of bariatric surgery, banding (19%), vertical banded gastroplasty (69%), or gastric bypass (12%). The control patients received usual care. The participants were 37 to 60 years of age, and the body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) was 34 or more in men and 38 or more in women, indicating the presence of moderate to severe obesity. At the time of this analysis (January 1, 2012), participants had been followed for up to 15 years.

During the follow-up period, type 2 diabetes developed in 392 participants in the control group and in 110 in the bariatric-surgery group, corresponding to incidence rates of 28.4 cases per 1000 person-years and 6.8 cases per 1000 person-years, respectively. The reduction in risk of becoming diabetic in the surgical group was only about 20% of the risk observed among the control subjects. The effect of bariatric surgery was influenced by the presence or absence of impaired fasting glucose (P = 0.002 for the interaction) but not by BMI (P = 0.54).  The study showed that the subjects who benefited the most from the surgery-induced weight loss were those who had elevated blood sugar before undergoing surgery.

Bariatric surgery thus appears to be markedly more efficient than usual care in the prevention of type 2 diabetes in moderately to severely obese persons. According to Dr. Claude Bouchard, a co-author of the study at Pennington Biomedical, this milestone research is the first to definitively show that weight loss, accomplished in obese patients with bariatric surgery, can prevent the onset of serious diseases such as type 2 diabetes in most peoplewho have a serious weight problem".  Dr. Lars Sjostrom, the senior author of the Swedish Obese Subjects project has been a visiting scientist at Pennington Biomedical over the last decade.

The Pennington Biomedical Research Center is a research campus of the Louisiana State University System and conducts basic, clinical, and population research focused on the prevention of common chronic diseases. The Center is located on a 234-acre campus in Baton Rouge, Louisiana, where it employs 500 scientists and support staff in state-of-the-art facilities.


*From the Institutes of Medicine (L.M.S.C., M.P., S.A., Å.A., B.C., P.J., C.M., C.P., S.R., K.S., E.S., P.-A.S., L.S.) and Surgery (H.L.), Sahlgrenska Academy at the University of Gothenburg, and the Nordic School of Public Health (H.W.), Gothenburg, and the Department of Surgery, University Hospital, Örebro  (I.N.) - all in Sweden; the Department of Chronic Disease Prevention, National Institute for Health and Welfare, Helsinki (M.P.); and Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge (C.B.).   


The Pennington Biomedical Research Center is at the forefront of medical discovery as it relates to understanding the triggers of obesity, diabetes, cardiovascular disease, cancer and dementia. It is a campus of Louisiana State University and conducts basic, clinical and population research. The research enterprise at Pennington Biomedical includes approximately 80 faculty and more than 25 post-doctoral fellows who comprise a network of 44 laboratories supported by lab technicians, nurses, dietitians, and support personnel, and 13 highly specialized core service facilities. Pennington Biomedical's more than 500 employees perform research activities in state-of-the-art facilities on the 222-acre campus located in Baton Rouge, Louisiana.