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

Abstract

Aims/hypothesis 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. Methods 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. Results 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 majorweight-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. Conclusions/interpretation 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

Weight Change–Adjusted Effects of Gastric Bypass Surgery on Glucose Metabolism: 2- and 10-Year Results From the Swedish Obese Subjects (SOS) Study

“…In most studies, results suggest that GBP is more effective for achieving major weight reduction and higher rates of diabetes remission compared with restrictive procedures (5,8,10). However, adjustments for degree of weight loss have seldom been performed in these analyses, and some reports indicate that magnitude of weight loss is the major determinant of whether obese patients with diabetes achieve remission both up to and after 2 years (6,12,(22)(23)(24). Furthermore, several recent studies challenge the importance of the incretin effect, implying that caloric restriction could instead be a main explanatory factor (25-29).…”

Risk of type 2 diabetes in patients with non-alcoholic fatty liver disease: Causal association or epiphenomenon?

“…Many more data are available on diabetes risk in relation to bariatric surgery-induced weight loss. In the Swedish Obese Subjects intervention study, surgery produced a systematic reduction of incident diabetes vs. obese matched controls [67]; the effect was directly associated with the amount of weight loss [68], not with baseline BMI [69]. In the same cohort of morbidly obese subjects undergoing surgery, weight loss was accompanied by a systematic reduction of serum liver enzymes at 2-year and 10-year follow-up, considered surrogate markers of steatosis, also proportional to the degree of weight loss [70].…”

Diabetes remission off medications is not a suitable endpoint for comparing bariatric/metabolic surgery with pharmacotherapy

“…Moreover, in larger studies involving patients with higher baseline BMI, such as the Swedish Obese Subjects (SOS) study, the degree of weight loss was significantly associated with glycaemic improvement; when stratified by weight, there were no differences between restrictive and malabsorptive (i.e. 'metabolic') surgical procedures [5,6]. Insofar as the present study was not powered to evaluate that question, as the authors correctly state, no conclusions different from what we already know from much bigger datasets can be reached.…”

“…However, we should be cautious of extrapolating these findings to less obese patients, as prior studies indicate that the degree of weight loss is predictive of glycaemic improvement [5], of the cardiovascular risk reduction [7], and many other important endpoints including albuminuria reduction, as well as improvement of sleep apnoea and steatohepatitis, for example.…”