Weight loss surgery dramatically delays or prevents the onset of type 2 diabetes in obese people, according to a new study carried out at the University of Gothenburg in Sweden.
Modifying eating habits alone is hard to maintain so the doctors decided to analyse the effects of bariatric surgery on the prevention of diabetes.
In the research, funded by the Swedish Research Council, they looked at 1,658 patients who underwent bariatric surgery and 1,771 obese matched controls. None of the participants had diabetes at baseline.
Some 19% of patients underwent banding, 69% had a vertical banded gastroplasty and 12% had gastric bypass.
Those taking part in the study were aged 37 to 60 and had a body mass index (BMI), a measure of weight versus height, of 34 or more in men and 38 or more in women.
‘This analysis focused on the rate of incident type 2 diabetes, which was a prespecified secondary end point in the main study. At the time of this analysis (January 1, 2012), participants had been followed up for to 15 years,’ the report says.
Despite matching, some baseline characteristics differed significantly between the groups; the baseline body weight was higher and risk factors were more pronounced in the bariatric surgery group than in the control group. At 15 years, 36.2% of the original participants had dropped out of the study, and 30.9% had not yet reached the time for their 15 year follow up examination.
uring 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 1,000 person years and 6.8 cases per 1,000 person years respectively.
‘Bariatric surgery appears to be markedly more efficient than usual care in the prevention of type 2 diabetes in obese persons,’ it concludes.
Co author Dr Lars Sjostrom said that some of the surgical patients will probably develop diabetes later but over a lifetime there will be a large difference.
The study also found that a person’s starting BMI did not predict whether patients would develop type 2 diabetes. Blood sugar levels at the beginning of the study, before surgery, were better indicators.
But the results may help doctors understand why the various types of surgery work and pick out the best candidates for the operation.
Sjostrom said more studies are needed and a cost analysis of the pros and cons of surgery, now underway, could be published in a year or so.
