The Swedish Obese Subjects study carried out at the Sahlgrenska Academy, University of Gothenburg found that, though weight-loss surgery is currently only offered to patients who exceed a certain BMI, surgical intervention would improve the health of many more people.
In order to meet the current selection criteria for weight-loss surgery, Swedish patients must have a body mass index (BMI) above 40 for healthy patients, or above 35 in combination with other risk factors such as type 2 diabetes. They examined the cases of 104 patients who were operated on despite their BMI being "too low" by current standards yet as a result had a 67% reduced chance of developing diabetes.
Those criteria were not created in a scientific manner and need to be improved, the scholars argue; weight-loss surgery offers significant health benefits for patients who do not meet today's criteria.
In their Diabetes Care paper, they monitored 104 patients who had weight-loss surgery before the current criteria were established and who would not have been offered the operation today. They determined that, 15 years after the procedure, these patients had a 67 percent lower risk of developing diabetes compared with a control group who were not operated on.
"The effect was the same as for patients who meet the current criteria," explains researcher Kajsa Sjöholm from the Sahlgrenska Academy, University of Gothenburg. "In other words, there is no proof that weight-loss surgery has a greater preventive effect against diabetes for patients who exceed today's BMI limit than for those who don't."
They also found that weight-loss surgery reduced the risk factors for cardiovascular disease among patients who are not currently eligible for this surgery. With reference to previous results published in the SOS study at the University of Gothenburg, which showed that weight-loss surgery generally results in a long-lasting reduction in weight and reduces the risk of diabetes, heart disease, stroke, cancer and premature death, the researchers believe that today's selection criteria should be re-evaluated.
According to the researchers, strict BMI limits can lead to patients with a high risk of future disease who would benefit from treatment being denied surgery. Previous papers argued that the selection can be improved by analyzing patients' insulin and glucose values.