Sex differences of oxidative stress markers in young healthy subjects are marker-specific in plasma but not in saliva

Background: Several studies showed there are sex differences in oxidative stress. An observational study analysing oxidative stress markers in young healthy men and women is lacking. Moreover, it is unclear whether the differences are related to sex hormones. Aim: The primary goal was to analyse differences in oxidative stress markers with regard to sex in plasma of young healthy subjects and whether differences are related to sex hormones. The secondary study compared oxidative stress markers in plasma with salivary samples. Methods: Plasma and saliva samples were analysed from 158 young healthy probands. Established spectro-photometric/fluorometric methods were used to quantify oxidative stress markers. Sex hormones were measured using ELISA kits. Results: In plasma, malondialdehyde and advanced glycation end products were significantly higher in women. Advanced oxidation protein products and the ferric reducing ability of plasma were higher in men. Sex hormones were not associated with oxidative stress markers. In saliva, analysed markers of antioxidant status were higher in men, but no sex differences were found in other markers. Conclusion: Observed parameters showed marker-specific sex differences in plasma, but these differences were not related to sex hormones. Plasma and saliva concentrations of biomarkers did not correlate, reflecting oral but not systemic conditions.