The study, conducted by researchers from the Karolinska Institute in Stockholm, Sweden, found that the savings made on medication and healthcare as a result of weight loss surgery meant that the overall cost of treating diabetes did not increase.
2,010 adults participated in the study, and their data were compared to a control group of 2,037. There was no difference in the overall cost of drugs between the control group and the weight loss surgery group without diabetes. But the overall drug costs of weight loss surgery patients with prediabetes or diabetes were cheaper.
In total, the healthcare costs of weight loss surgery patients were lower in those with diabetes or prediabetes. The researchers suggested that the cheaper costs could be linked to the beneficial effects of weight loss surgery on diabetes management; many type 2 diabetes patients go into remission following surgery. As a result, they require fewer drugs and hospital appointments, and tend to develop fewer complications.
However, the researchers were unable to gather certain data, a limitation acknowledged in the study. It relied on self-reported drug costs, and did not include data relating the cost of nursing home, medical equipment, dietitians or psychologists.
Prioritising type 2 diabetes for weight loss surgeryThe researchers concluded that, owing to the fact that weight loss surgery can make type 2 diabetes management cheaper, people with type 2 diabetes and obesity should be prioritised for weight loss surgery over people with obesity but not type 2 diabetes, once lifestyle changes and drugs have failed to improve blood glucose control.
Currently, the NHS prioritises for weight loss surgery based on BMI: those with the highest BMI will receive weight loss surgery. This study argues that the priority system is flawed.
"Greater weight should be given to preoperative blood sugar status to help identify the patients who have the most benefit from bariatric surgery," co-author Martin Neovius told Reuters by email.
"We have shown previously that this makes sense from a health outcomes perspective, and now we show that it makes sense also from an economic perspective."
The researchers wrote: "to our knowledge, this is the first prospectively controlled study to assess long-term healthcare costs in obesity surgery patients according to their preoperative diabetes status versus matched controls."
"We show that for obese patients with type 2 diabetes, the upfront costs of bariatric surgery seem to be largely offset by prevention of future health-care and drug use. This finding of cost neutrality is seldom noted for health-care interventions, nor is it a requirement of funding in most settings."
The findings were published in The Lancet Diabetes and Endocrinology.