Diabetes risk in relation to weight loss, weight stability and degree of obesity - The Swedish Obese Subjects (SOS) study
M. Peltonen1, L. Sjöström2 & L. Carlsson2
Objective: Among severely obese individuals, surgically induced weight loss reduces the risk for type 2 diabetes. The aim of this study was to analyse the incidence and remission of type 2 diabetes among individuals with different degrees of obesity losing weight, and compare them with obese individuals remaining weight stable during follow-up.
Research design and methods: The ongoing non-randomized prospective controlled Swedish Obese Subjects (SOS) intervention study enrolled 2010 obese persons who received bariatric surgery and 2037 contemporaneously matched obese controls. Health examinations with anthropometric measurements and laboratory analyses were conducted at baseline and at 2- and 10-year follow-up. Diabetes was defined by fasting venous whole blood glucose 6.1 mmol/litre or more, and/or self-reported diabetes medication. Two- and 10-year diabetes risk was assessed by initial BMI and weight changes during follow-up. Incidence and remission rates were calculated for those without and with diabetes at baseline, respectively.
Results: Among weight stable obese individuals with BMI <35, 3540, and 4045 both at baseline and at 2-year follow-up, type 2 diabetes incidence rates were 6.5%, 7.7% and 9.3%, respectively. Among those with initial BMI of 3540, 4045 and ≧ 45 attaining five BMI-unit weight reduction, the corresponding rates were 2.4%, 2.0% and 3.4%, respectively. In patients with diabetes at baseline and who attained a 5 BMI-unit reduction at year 2, remission rates were independent of the initial degree of obesity. Similar results were observed with the 10-year follow-up data.
Conclusions: A BMI reduction of 5 units, independent of the initial degree of obesity, is associated with a reduction of diabetes risk compared with weight stability at any obese BMI-level.
Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.
Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.