Background: Metabolic bariatric surgery (MBS) is the most effective treatment of severe obesity, a global epidemic associated with multiple comorbidities. MBS may result in type 2 diabetes (T2D) remission. The Individualized Metabolic Surgery (IMS) score aims to predict the remission and guide procedure selection between the two most common MBS procedures, laparoscopic sleeve gastrectomy (LSG) and Roux-en-Y gastric bypass (LRYGB). The Finnish SLEEVEPASS trial is a randomized multicenter clinical trial with long-term follow-up comparing LSG and LRYG. Severe obesity is associated with low-grade chronic inflammation, which is considered to contribute to the development of comorbidities and increased cancer risk. MBS may cause nutritional deficiencies, and micronutrient supplements are recommended postoperatively.
Aims: The aim of this thesis was to evaluate and compare long-term metabolic and nutritional effects of LSG and LRYGB. Study I aimed to validate the IMS score. Study II assessed the effect of MBS on low-grade chronic inflammation using high-sensitivity C-reactive protein (hs-CRP). Study III evaluated long-term nutritional deficiencies and adherence to micronutrient supplements at 10 years.
Results: IMS score correlated with the probability of T2D remissions, but there was no statistically significant difference between the procedures to guide procedure selection. MBS resulted in long-term decrease in hs-CRP, which correlated with BMI through follow-up. Long-term nutritional deficiencies were rare after MBS. There was a statistically significant difference between LSG and LRYGB in iron deficiency. Adherence to micronutrient supplements was higher in LRYGB group.
Conclusions: IMS score demonstrated strong prediction of T2D remission, but did not facilitate procedure selection. Hs-CRP decreased sustainably after MBS with weight loss as the driving force. Nutritional deficiencies were relatively rare after MBS, except for iron deficiency, which should be monitored, especially after LRYGB and considered in procedure selection.