The Impact of Gastric Leptin and Leptin Receptor Expression on Metabolic Outcomes Post Laparoscopic Sleeve Gastrectomy

Purpose: Obesity is a growing global crisis, with predictions that nearly half of the world's population will be overweight or with severe obesity by 2030. Metabolic bariatric surgery, effective for those unable to lose weight through conventional methods, results in significant weight loss and alleviates associated medical problems. This study investigates changes in gastric leptin (LE) and leptin receptor (LER) expression following laparoscopic sleeve gastrectomy (LSG) and explores their metabolic contributions to surgical outcomes.

Materials and methods: Immunohistochemical staining for LE and LER was performed on gastric tissue biopsies from 54 patients pre- and post-LSG. Expression levels were scored for each epithelium and connective tissue component. Changes in these scores post-LSG were analyzed and correlated with body mass index (BMI), total weight loss (TWL), blood hemoglobin A1c, blood cholesterol, and triglyceride levels. Statistical analysis included paired t-tests, Pearson correlation coefficients, and one-way ANOVA.

Results: Significant decreases in LE and LER receptor expression were observed post-LSG, correlating with reductions in BMI, blood hemoglobin A1c, total cholesterol, and triglyceride levels. The mean BMI decreased from 46.82 kg/m2 pre-surgery to 32.45 kg/m2 at 1 year post-surgery (p < 0.001). Hemoglobin A1c levels reduced from 7.8% to 5.9% (p < 0.001). Total cholesterol and triglyceride levels showed significant reductions, with cholesterol decreasing from 220 mg/dL to 180 mg/dL (p < 0.001) and triglycerides from 180 mg/dL to 120 mg/dL (p < 0.001). Pearson correlation coefficients demonstrated strong negative correlations between LE expression and BMI (r = -0.65, p < 0.001) and between LER expression and hemoglobin A1c (r = -0.60, p < 0.001).

Conclusions: Beyond weight reduction, the decreased expression of gastric LE and LER post-LSG contributes metabolically to weight loss and improved associated metabolic parameters following the metabolic bariatric surgery.