Incidence and remission of type 2 diabetes in relation to degree of obesity at baseline and 2 year weight change: the Swedish Obese Subjects (SOS) study

Kajsa Sjöholm, Pia Pajunen, Peter Jacobson, Kristjan Karason, C. David Sjöström, Jarl Torgerson, Lena M. S. Carlsson, Lars Sjöström, Markku Peltonen

The aim of this work was to analyse the rates of incidence and remission of type 2 diabetes in relation to baseline BMI and weight change in the prospective, controlled Swedish Obese Subjects (SOS) study. Three-thousand four-hundred and eighty-five obese individuals receiving bariatric surgery or conventional treatment were grouped into four baseline BMI categories (<35, 35-40, 40-45 or ≥45 kg/m(2)) and five weight-change categories according to their BMI at 2 years (increase [≥1 BMI unit increase], no change [less than 1 BMI unit change], minor reduction [-1 to -9 BMI units], medium reduction [-10 to -14 BMI units] and major reduction [< -15 BMI units]). The incidence and remission of diabetes at 2 years was assessed. Among individuals with no weight change, diabetes incidence rates were 5.5%, 7.4%, 8.3% and 5.2%, in the four baseline BMI categories, respectively. In those with an initial BMI of 35-40, 40-45 and ≥45 kg/m(2) who attained a minor reduction in weight, the corresponding rates were 1.3%, 1.2% and 3.4%, respectively. In both the medium- and major-weight-reduction groups, diabetes incidence was ≤0.5%. Among individuals with diabetes at baseline, the remission rates were 15.3-26.9% in the no-weight-change groups, and 48.1-70% for individuals who attained a minor weight reduction. In the medium- and major-weight-reduction groups, the remission rate was 77-97%. There were no differences in 2 year incidence and remission rates between different baseline BMI groups that achieved the same degree of weight reduction. In obese individuals, the favourable effect of weight reduction on type 2 diabetes incidence and remission is independent of initial BMI. Trial registration ClinicalTrials.gov number NCT01479452.