Reference values of thiole disulphide in newborn

Aim: The oxidative balance is the name given to the arrangement between the development of free radicals in the body (oxidation) and the removal of these radicals with the antioxidant system. Thiols are a part of the antioxidants trying to preserve this balance in the body. The aim of this study was to determine the reference values of thiol-disulfide, a marker of the oxidant-antioxidant system, in newborns. Material and Method: The study was conducted at the obstetrics and gynecology clinic and newborn outpatients of a tertiary hospital. Fully healthy term babies aged 1-28 days without any pathological finding in the prenatal, natal and postnatal periods were included in the study. Venous blood at a volume of 2 cc was obtained from all babies for the thiol-disulfide measurement and the measurements were performed with the Erel and Neşelioğlu method. Results: The reference values for mean thiol-disulfide values in the newborn period were 252.45±47.95 (158.47-346.43) µmol/L for native thiol, 286.74±50.22 (188.31-385.17) µmol/L for total thiol, and 17.49±2.70 (13-23) µmol/L for disulfide. The disulfide/native thiol ratio was 6.96±1.06 (4.88-9.03), the disulfide/total thiol ratio was 6.10±0.80 (4.53-7.66), and the native thiol/total thiol ratio was 87.78±1.61 (84.13-90.93). The native thiol and total thiol values and the native thiol/total thiol ratio decreased with increasing postnatal day while the disulfide/native thiol and disulfide/total thiol ratios increased and the disulfide values showed no change. Conclusion: We determined the thiol-disulfide reference values in healthy term newborns in this study. Our results indicate that the oxidative stress increased slightly over time in the postnasal period in healthy term newborns. However, evaluation together with other markers would be more appropriate to reach a more accurate conclusion on the matter. Future well-designed studies with a wider participation and where oxidative stress markers are used in combination are needed. Keywords: Newborn, Thiol/Disulfide Balance, Oxidative stress, Antioxidant system