Abstract
Introduction: Albumin oxidation or S-cysteinylation (S-Cys) of its free cysteine residue has been shown to be a measure of oxidative stress. While it is subject to artificial ex-vivo elevations, freshly processed samples could serve as a theoretical biomarker of any number of inflammatory states.
Hypothesis: S-Cys Albumin is associated with atherosclerotic cardiovascular disease (ASCVD) and its risk factors that increase oxidative stress.
Methods: We enrolled 137 patients evaluated for chest pain in a single-center cross-sectional study from May 2016 through March 2020. Plasma and serum samples were gathered and immediately processed for analysis of intact albumin by high pressure liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). Statistical analysis included a spearman's coefficient, and two-tailed linear regression of the relative fractional abundance (RFA) of S-Cys albumin and clinical variables.
Results: S-Cys-albumin levels were significantly decreased in those with a previous history of coronary stenting (Plasma β=-0.032, p=0.005; Serum β=-0.032, p=0.012; n=24) and MDD (Plasma β=-0.016, p=0.132; Serum β=-0.026, p=0.021, n=34). S-Cys-albumin levels were significantly elevated in those with a previous history of peripheral artery disease (Plasma β=0.051, p=0.015; Serum β=0.055, p= 0.016; n=6) and chronic infections (Plasma β=0.023, p=0.033; Serum β=0.021, p =0.069; n=30). CAD by history was not significantly different (Plasma β=0.012, p=0.19; Serum β=0.01, p =0.3; n=57). Spearman's coefficient demonstrated a positive correlation between age (plasma rho = 0.1877, p = 0.0576; serum rho 0.2641, p = 0.007; n=103), BMI (plasma rho = 0.2089, p = 0.0342; serum rho = 0.1287, p = 0.195; n=103), Framingham risk score (plasma rho = 0.2607, p = 0.0523; serum rho = 0.3595, p = 0.0065; n=56), ASCVD risk score (plasma rho = 0.3526, p = 0.0083; serum rho = 0.472, p = 0.0003; n=55), heart rate (plasma rho = 0.2225, p = 0.0239, serum rho = 0.1678, p = 0.0902; n=103) and NT-pro-BNP (plasma rho = 0.3398, p = 0.0319; serum rho 0.3937, p = 0.012; n=40).
Conclusion: S-Cysteinylated Albumin is associated with several measure of ASCVD and its risk factors. It may be a marker of the underlying oxidative stress.