microRNA profiling and the effect on metabolic biomarkers and weight loss after laparoscopic sleeve gastrectomy: A prospective cohort study

Background: Epigenetic changes after bariatric surgery are of increasing interest; we evaluated the levels of two circulating microRNAs (miRNA-222 and miRNA-146a) before and after the laparoscopic sleeve gastrectomy (LSG) and the effect of weight loss on the levels of metabolic biomarkers. Materials and Methods: We prospectively evaluated patients pre- and 12 months post-LSG for percent excess weight loss (%EWL), miRNAs levels, metabolic biomarkers (leptin, ghrelin, peptide YY, and glucagon peptide-1 [GLP-1]) levels from August 2019 to September 2021. Results: Significant differences were observed in the miRNA146a-3p (median: 0.64 (0.012-2.68) vs. 1.07 (0.1-3.6); P = 0.019) and miRNA222-5p (median 1.80 (0.1–3.61) vs. 1.19 (0.1-3.68); P = 0.003) levels before and after (12 months) LSG; fasting leptin, ghrelin, insulin, total cholesterol, high- and low-density lipoproteins, fasting blood sugar (FBS), and triglyceride levels also showed significant differences. Significant changes were observed in postprandial values of glucagon-like peptide l (GLP-1) (P = 0.0001) and peptide YY (P = 0.0006) 12 months after LSG. Homeostatic model assessment of insulin resistance (IR) was significantly correlated with %EWL, miRNA146a, and miRNA222-5p (P = 0.002). Postoperatively measured miR146a-39 and miRNA222-5p showed significant coefficient of determination R2 of 0.184 (P = 0.008) and 0.259, P = 0.0007 toward %EWL, respectively. Furthermore, significant correlations of miRNA146a were observed with FBS and IR. Conclusions: LSG-mediated weight loss affected the plasma levels of miR146a and miR222-5p. Due to the simultaneous decrease of ghrelin and increase of postprandial hormones (peptide YY and GLP-1), medical problems in patients with obesity were reduced. This study identified miRNAs as the new markers in the treatment, diagnosis, and therapeutic direction of patients with obesity.