...our data demonstrates that in terms of diabetes prevention and improvement of cardiovascular risk factors, patients with BMIs lower than the current limit would benefit from surgery.
Professor Lena Carlsson
Health experts from the University of Gothenburg
are calling for a reduction in the body mass index (BMI) that obese patients must exceed in order to qualify for weight-loss – or bariatric – surgery. The researchers contend that earlier surgical interventions could improve the health of many more people, reducing the prevalence of conditions such as Type 2 diabetes
The recommendations have been made by a team at the University’s Sahlgrenska Academy
, and are based on the findings of the Swedish Obese Subjects (SOS) study – an initiative that monitored more than 4,000 obese patients over a 20-year period. During the course of this expansive investigation, half of the participants underwent weight-loss surgery and half were treated by the Swedish primary healthcare service. 104 of the patients who underwent bariatric surgery would not have qualified for the procedure under current rules as their BMI was ‘too low’.
The experts, whose latest results have been published in the journal Diabetes Care
, found that weight-loss surgery significantly lowered the chances of this subsection developing diabetes. In fact, the risk was reduced by 67 per cent. Participating scientist Professor Lena Carlsson from the Academy’s Institute of Medicine
spoke to ScienceOmega.com
about the benefits that would result from a reduction in the BMI limit.
"Our study demonstrates that when patients undergo bariatric surgery, diabetes incidence is reduced both in those who meet the BMI-based criteria and in those who do not," she explained. "Moreover, in our earlier studies of other endpoints such as overall mortality, cancer and cardiovascular events, we observed that the treatment benefit is not related to the degree of obesity as measured by BMI."
In light of these findings, I asked Professor Carlsson about the level to which she would like to see the minimum BMI for bariatric surgery reduced.
"I cannot answer that question because although some of the patients with whom we’ve been working have BMIs that are too low to meet the current criteria, they are all obese," she replied. "Even so, our data demonstrates that in terms of diabetes prevention and improvement of cardiovascular risk factors, patients with BMIs lower than the current limit would benefit from surgery."
At present, Swedish patients – if healthy in other respects – must have a BMI of 40 or above in order to qualify for weight-loss surgery. In instances where there are other risk factors such as the presence of Type 2 diabetes, this benchmark is set at 35. In order to receive bariatric surgery on the United Kingdom’s National Health Service (NHS)
, patients must also have a BMI equal to, or greater than, 40. However, Professor Carlsson and her colleagues argue that such standards have not been devised in a scientific manner.
"These figures are based solely on the opinions of experts," she explained. "No long-term studies have evaluated different cut-offs in terms of their treatment benefits – their capacity to prevent serious obesity-related problems. To supplement BMI, I think that we need to find additional criteria in order to direct resources to those who will benefit most from bariatric surgery."
To conclude our conversation, I asked Professor Carlsson whether this course of action is likely to prove cost effective. Would the long-term benefits brought about by earlier surgical interventions outweigh the initial cost of conducting a greater number of bariatric procedures?
"We are investigating this issue at the moment so I cannot offer a conclusive answer at this point," she conceded. "It is clear that BMI is not a good marker for treatment benefit. We need to find other markers to help to direct surgical intervention to the patients who will benefit the most from treatment. This would also increase the likelihood that the cost of these surgical interventions will be lower than the cost of treating preventable diseases in the long term."