Glycoprotein Determination with NMR Spectroscopy to Evaluate the Effect of Metabolic Surgery over the Proinflammatory State of Patients with Obesity

Abstract

Aim: Patients with obesity present with a proinflammatory state generally quantified by measuring acute-phase proteins (APP) such as C reactive protein (CPR) which shows however great variability. The determination of glycoproteins by using MRI spectroscopy, specifically acetyl groups of N-acetylglucosamine and N-acetylgalactosamine (GlycA), and acetyl groups of N-acetylneuraminic acid (GlycB), allows us to measure the aforementioned proinflammatory state with less interindividual variability than other biomarkers such as CPR, high-sensitivity CPR (hsCPR), or IL-6. The aim of this study is to show the influence of metabolic surgery over highly sensitive inflammatory markers (GlycA, Glyc B, and Glyc F).

Material and methods: This prospective observational study included 52 patients undergoing metabolic surgery. Plasma levels of GlycA, GlycB, GlycF, and ratios HWGlycA and HWGlycB were measured before and 18 months after surgery.

Results: The cohort had a mean age of 46.3 years, 63.5% were women, with a mean BMI of 43.6 kg/m², and abdominal circumference of 133.5 cm. Surgical techniques included BRYGB (55.7%), RYGB (19.2%), and SG (17.3%). GlycA decreased significantly postoperatively (mean difference: - 79.3 units; Cohen's d = 1.99), as did GlycB (- 35.9; d = 1.88) and GlycF (- 43.7; d = 2.22), with all p < 0.001.

Conclusions: Metabolic surgery significantly reduces the proinflammatory state in patients with obesity, as demonstrated by large effect sizes and reductions in NMR-measured glycoproteins. These markers may offer a reliable method to monitor inflammation beyond traditional acute-phase reactants.

Keywords: Anti-inflammatory effect; Glycoproteins; Metabolic surgery.