Losing enough weight to reduce one’s BMI by five units can dramatically decrease the risk of diabetes–regardless of initial weight, according to new research from the National Institute for Health and Welfare in Finland and the University of Gothenburg. Weight loss surgery has been shown to be particularly effective in treating diabetes, which prompted the researchers to investigate how weight loss has such a dramatic effect on diabetes. They studied about 2000 patients from the Swedish Obese Subjects (SOS) study who received weight loss surgery and a control group of another 2000 who were receiving non-surgical treatment for obesity. The patients were evaluated for BMI and diabetes at the beginning of the study, as well as 2 years and 10 years later.
The researchers found that among patients with BMI less than 35, between 35 and 40, and between 40 and 45, who did not lose weight after two years, type 2 diabetes incidence rates were 6.5 percent, 7.7 percent and 9.3 percent, respectively. The patients who had an initial BMI of 35-40, 40-45 and ≥45 who lost at least five BMI units after two years had lower rates of diabetes, at 2.4 percent, 2.0 percent and 3.4 percent respectively. Through further analysis, they found that the rate of patients whose diabetes was resolved after losing five BMI units was independent of the starting BMI at all BMI levels that they tested. This trend held at 10 years post-surgery. The findings suggest that dropping five BMI units, which is about the equivalent of dropping 35 pounds for a 5’10” tall man weighing about 280 pounds (BMI 40), can reduce the risk of having diabetes. Further, it held true for all patients; even the severely obese showed dramatic improvements.
Dropping five BMI units, however, is no easy feat. Even with weight loss surgery, it is essential that patients make healthy lifestyle changes. Because weight loss surgery has been shown to be so effective in resolving diabetes, it leads to the question of whether one procedure more effectively treats diabetes. A new study presented at the International Congress of Endocrinology this month found that the tested weight loss surgeries appeared to be equally good at treating diabetes. The findings indicated that diabetes improvement in surgery patients is likely to be due to the amount of weight loss itself, not the type of procedure.
The researchers also used data from the SOS study, and looked at the roughly 2000 weight loss surgery patients by procedure type: 376 gastric band, 265 gastric bypass, and 1369 vertical banded gastroplasty. In looking at the 10 year data, the researchers found that when the extent of the individuals’ weight loss was taken into account, no significant difference in the changes to insulin and glucose levels between the three groups, and three weight loss procedures. Additionally, patients who lost the same amount of weight saw improvements in their blood glucose and insulin levels to a similar extent, regardless of surgery type.
“Bariatric surgery is clearly effective in reducing weight in patients, but the current mystery is why so many patients appear to cure themselves of diabetes shortly after the operation, said Associate Professor Markku Peltonen, Director at the National Institute for Health and Welfare. He concluded that “it would be expected that some methods of bariatric surgery would be more effective at treating diabetes than others due to the different ways they alter the passage of food through our gut. When we factored in the weight lost following surgery we found that no procedure was any better at treating diabetes than another.”
We spoke with Dr. RoseMarie Jones, expert weight loss surgeon in Indiana, about the research. She said, “This is exciting new long-term data from the SOS study. There is now ample evidence that bariatric surgery is the most effective therapy for type 2 diabetes. Reduction in caloric intake and the resulting weight loss are the most likely mechanisms of improvement in diabetes following weight loss surgery, as supported by the SOS data that weight loss correlated with diabetes remission, regardless of the type of surgery, and also regardless of the starting BMI,” Dr. Jones concluded.
Related Reading: Surgery Superior for Obese People with Diabetes
Weight Loss Studies & Clinical