The Impact of Bariatric Surgery on Glutathione Synthesis in Individuals with Severe Obesity

Authors

Hong Chang Tan
Jean W Hsu
E Shyong Tai
Shaji Chacko
Jean-Paul Kovalik
Farook Jahoor

Publication Date

8-9-2024

Journal

Antioxidants

DOI

10.3390/antiox13080967

PMID

39199212

PMCID

PMC11351666

PubMedCentral® Posted Date

8-9-2024

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

glycine deficiency, severe obesity, glutathione synthesis, bariatric surgery

Abstract

Glycine is deficient in individuals with obesity but improves following bariatric surgery. Glycine deficiency could impair glutathione (GSH) synthesis and worsen oxidative stress. We examined the impact of obesity-associated glycine deficiency and bariatric surgery on GSH synthesis. Twenty-one participants with severe obesity and twenty-one healthy weight controls were recruited. [1,2-13C2] glycine was infused to measure the erythrocyte (RBC) GSH synthesis rate. Participants with obesity underwent bariatric surgery, and 19 were restudied six months post-surgery. Compared to healthy weight controls, individuals with obesity had significantly lower concentrations of RBC GSH (2.43 ± 0.23 vs. 2.63 ± 0.26 mmol/L, p < 0.01). However, there were no differences in GSH fractional synthesis rate [78.0 (51.4–123.7) vs. 76.9 (49.3–110.1) % pool/day, p = 0.58] or absolute synthesis rate [1.85 (1.25–3.32) vs. 1.92 (1.43–3.03) mmol/L RBC/day, p = 0.97]. Despite a post-surgery increase in glycine concentration, no statistically significant changes in RBC GSH concentration or synthesis rates were detected. Further, the significant correlation between plasma glycine and RBC GSH concentration at baseline (r = 0.46, p < 0.01) was also lost following bariatric surgery. GSH concentration was significantly lower in participants with obesity, but bariatric surgery did not significantly increase GSH concentrations or synthesis rates.