Serum stearic acid/palmitic acid ratio as a potential predictor of diabetes remission after Roux-en-Y gastric bypass in obesity

Abstract

Endogenous fatty acidmetabolism that results inelongation and desaturation lipid products is thought to play a role in the development of type 2 diabetes mellitus (T2DM). In this study, we evaluated the potential of estimated elongase and desaturase activities for use as predictive markers for T2DM remission after Roux-en-Y gastric bypass (RYGB). The results of a targeted metabolomics approach from 2 independent studies were used to calculate 24 serum FA concentration ratios (product/precursor). Gene expression data from an open public data set was also analyzed. In a longitudinal study of 38 obese diabetic patientswithRYGB,we found higher baseline stearic acid/palmitic acid(S/P) ratio. This ratioreflects anelovl6-encodedelongase enzyme activity thathasbeenfoundtobe associated with greater possibility for diabetes remission after RYGB [odds ratio, 2.16 (95% CI 1.10-4.26)], after adjustment for age, gender, body mass index, diabetes duration, glycosylated hemoglobin A1c, and fasting C-peptide. Our results were validated by examination of postsurgical elovl6 gene expression in morbidly obese patients. The association of S/P with the metabolic status of obese individuals was further validated in a crosssectional cohort of 381 participants. In summary, higher baseline S/P was associated with greater probability of diabetes remissionafterRYGBandmay serve as adiagnosticmarker inpreoperativepatient assessment.