Long-Term Improvement of Chronic Low-Grade Inflammation After Bariatric Surgery

Bariatric surgery (BS) was shown to improve inflammatory markers in previous short-term follow-up studies. The aim of the present study was to assess the long-term effects of BS on chronic low-grade inflammation markers related to severe obesity. Moreover, the meaning of the type of BS procedure as well as the remission of type 2 diabetes (T2D) for inflammatory status up to 4 years after BS was analyzed.

In a retrospective cohort study including 163 patients at baseline, inflammatory and metabolic parameters were assessed at 4 time points: before surgery (baseline), 6 months after surgery (visit 1), 2 years after surgery (visit 2), and 4 years after surgery (visit 3). Univariate regression analysis was used to identify variables that were thought to determine change in inflammatory parameters.

CRP, hs-CRP, leucocytes, and ferritin significantly declined in the mid- and long-term according to the U-shaped curve of weight loss (p<0.001). Change in body mass index (BMI) at long-time follow-up showed a significant linear effect on change in leucocytes (B=0.082; p<0.001) and change in hs-CRP (B=0.03; p<0.05). There was a strong, positive correlation between T2D and hs-CRP at visit 2 (r_s=0.195; p<0.05) and visit 3 (r_s=0.36; p=0.001). With regard to type of surgery and gender, there were no significant differences in inflammatory parameters.

BS is able to reduce obesity-related chronic low-grade inflammation up to 4 years after surgical intervention. The improvement in metaflammation is related to the change in BMI and remission of T2D in the long-term.