Influence of Bariatric Surgery on Endothelial and Glycocalyx Biomarkers in Obesity and Type 2 Diabetes

CONTEXT: Bariatric surgery is associated with reduced risk of cardiometabolic disease in obesity and type 2 diabetes (T2D). The mechanisms are not fully understood, but improvement in endothelial dysfunction has been implicated. OBJECTIVE: This work aimed to assess endothelial biomarkers before and after surgery. METHODS: A prospective cohort study with 2-year follow-up was conducted at a single center in Stockholm, Sweden. Participants included adults undergoing bariatric surgery, 28 with and 33 without T2D. Intervention included Roux-en-Y gastric bypass preceded by a 2-week low-calorie diet (LCD). Main outcome measures included plasma concentrations of glycocalyx biomarkers (hyaluronan [HA] and syndecan-1), E-Selectin, von Willebrand factor (VWF), and thrombomodulin (TM). RESULTS: At baseline, patients with diabetes had higher concentrations of E-Selectin (P = .041) whereas other biomarkers did not differ between groups. After LCD, E-Selectin, syndecan-1, and VWF were reduced. Two years after surgery, TM was unchanged whereas E-Selectin decreased, geometric mean (CV%) 41 (40) to 24 (61) ng/mL, syndecan-1 from 50 (73) to 38 (81) ng/mL, and VWF from 120 (52) to 103 (45)%, while HA increased from 25 (96) to 40 (78) ng/mL (P < .001 for all). E-Selectin initially declined faster in patients with diabetes (P < .003); otherwise the biomarker changes did not differ between groups. Variables with the highest predictive value for improvement in biomarkers were decrease in body weight and fat mass and increase in insulin sensitivity (HOMA-IR). CONCLUSION: Bariatric surgery is associated with sustained, beneficial alterations in biomarkers of glycocalyx and endothelial function in patients with obesity, both with and without T2D. It is suggested that reduced body weight/fat mass and improved insulin sensitivity are of particular importance for these alterations.