T. Lo1, G. Williams1, K. Heshmati1, A. Tavakkoli1, D. C. Croteau-Chonka1, E. G. Sheu1 1Brigham And Women’s Hospital,Metabolic Surgery,Boston, MA, USA
Introduction:
Laparoscopic sleeve gastrectomy (LSG) has been proved to be an effective weight loss procedure and has a positive impact on obesity-related comorbidities. We hypothesize that the effects of LSG are reflected in the immune-metabolic changes in a longitudinal human cohort study.
Methods:
Prospective data has been collected from enrolled human subjects from a single institution. Parameters of weight, comorbidities, pulmonary function tests, and trends in blood biomarkers (HbA1C, inflammatory and hormonal biomarkers) were observed from pre-operative baseline to 1 year in a 3-monthly interval follow ups. Subcutaneous and omental adipose tissue biopsies were collected perioperatively in addition to leukocytes every 3 months for RNA sequencing. We have included our interim analysis on immune-metabolic and hormonal profiling in this abstract.
Results:
16 subjects were enrolled (M: F, 3:13; mean age, 45 years old; mean body mass index (BMI) 43.18±5.78 Kg/m2). 13 subjects have competed their 3 month follow up visit with 1 subject dropout. There was a significant reduction in mean total body weight loss at 3 months (17.2±1.2%) and at 6 months (24.99±3.70%). Improvements in obesity-related comorbidities have been observed either by disease remission or reduction in medication. 75% of patients with hypertension, 50% with type 2 diabetes, and 50% dyslipidemia ceased their medication requirements by 3 months after LSG. Significant improvements in hormonal biomarkers such as insulin (P<0.001), HbA1C (P<0.05), ghrelin (P<0.001) and leptin (P<0.001) were seen by 3 months after LSG. Surprisingly, reductions in ghrelin levels did not predict weight loss. Immunologic markers such as total white cell counts, neutrophils, and C reactive protein (CRP) were found to have significantly decreased as early as 3 months comparing to baseline. Two patterns of CRP responses were seen: one set of subjects had elevated CRP at baseline that resolved to normal by 3 to 6 months post-op. A second subset had normal CRP levels at baseline that remained stable post-op. Subjects with a baseline, low CRP achieved more weight loss (P<0.001). White cells composition was also altered after LSG, with a significant decrease in neutrophils and increase in lymphocytes. Changes in neutrophil and lymphocyte fraction were reduced in subjects with metabolic diseases (P<0.01), whilst other immunological markers and weight outcomes did not differ between the two groups.
Conclusion:
This interim analysis from our study suggests that LSG induces significant immuno-metabolic changes in obese individuals as early as 3 months post-operatively. The improvement in CRP as well as white cells composition alteration tracks closely with weight loss, suggesting that the immune response plays a role in LSG. Future analyses including a larger sample size and RNA sequencing data will provide additional insights into predicting weight outcomes and metabolic response after LSG.