Remission rates from T2DM were not statistically different after laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB) among all patients and among patients with mild, moderate and severe diabetes stratified by the Individualized Metabolic Surgery (IMS) score, according to a study of merged data of two randomized clinical trials - SLEEVEPASS and SM-BOSS.
The outcomes featured in the paper, ‘Validation of the Individual Metabolic Surgery Score for Bariatric Procedure Selection in the Merged Data of Two Randomized Clinical Trials (SLEEVEPASS and SM-BOSS)’, published in SOARD, noted that IMS score seemed to be useful in predicting long-term T2D remission after bariatric surgery.
The international team of authors to validate the Individualized Metabolic Surgery (IMS) score in a large prospective cohort assessing the feasibility of the IMS score in both tailoring the metabolic surgery procedure choice for patients with T2D and predicting the sustainability of T2D remission. The authors merged individual patient data from SLEEVEPASS and SM-BOSS comparing LSG and LRYGB with five-year follow-up data.
The study design, rationale, and methods of both RCTs have been previously reported30,31. The study protocols were approved by the local ethics committees of each participating hospital, the trials were conducted in accordance with the principles of the Declaration of Helsinki and registered at the clinical trials registry of the National Institutes of Health (ClinicalTrials.gov NCT00356213, NCT00793143). All patients gave written informed consent.
The IMS score was calculated based on four different independent preoperative variables predicting long-term remission of T2D: duration of T2D in years, the number of diabetes medications, insulin use, and glycaemic control (glycated haemoglobin level, A1c <7%). Based on the calculated scores, patients were categorized into three different groups according to IMS score T2D severity stage: mild (IMS score ≤25), moderate (IMS score >25 to ≤95), and severe (IMS score >95) and the T2D remission rates were assessed according to these groups. Long-term T2D remission was defined according to ADA consensus statement as A1c<6.5%, fasting blood glucose 126 mg/dl, and off T2D medications at five years or more after surgery.
Outcomes
In total, 139 (89.7%) patients had the preoperative data for IMS calculations, and 135 (87.1%) were available for follow-up at five years. The T2D remission rate five years after LSG was 49.3% (n=33/67) and 55.8% (n=38/68) after LRYGB (p=0.418).
Furthermore, 121 patients were available for both IMS score calculation and T2D remission analysis at five years. In total, 52.6% (n=63/121) of these patients had complete remission of T2D at five years. Within the severity stages, the rates in achieving long-term remission at five-year follow-up were 86.5% (n=32/37) in the mild stage, 43.9% (n=29/66) in the moderate stage, and 11.1% (n=2/18) in the severe stage (p<.001). The remission rates after LSG and LRYGB did not differ statistically significantly between the operations in any of the severity stages.
The change in BMI differed significantly (p=0.043) between the severity stages in patients who underwent RYGB with the highest BMI loss associated with T2D mild stage. In patients who underwent LSG, there were no significant differences (p=0.454) in BMI change between the T2D severity stages.
The difference in T2D remission between the IMS score T2D severity stages was statistically significant (p<0.001). The odds for T2D remission were the highest in the mild stage (mild vs. moderate p<0.001; mild vs. severe p<0.001). There was also a statistically significant difference between the moderate and the severe stage in the odds for T2D remission (p=0.020).
The authors stated that the outcomes suggest that IMS score does not facilitate the procedure selection between LSG and LRYGB, but IMS could be used as a general predictive model for T2D remission in patients with severe obesity.
“In our study, remission rates of T2D were not statistically different after LSG and LRYGB among all patients and among patients with mild, moderate and severe diabetes stratified by the IMS score,” the authors concluded. “However, the study may be underpowered to detect differences due to small number of patients in each subgroup.”
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