Relationship between serum bilirubin and uric acid to oxidative stress markers in Italian and Czech populations

SummaryRecently, a South-to-North oxidative stress marker gradient has been reported; consistent with known differences in the incidence of coronary heart disease between southern and northern European countries. The aim of the present study was to compare the plasma concentrations of 7-oxocholesterol (7OxCH) and 7β-hydroxycholesterol (7BCH) with systemic antioxidants in healthy Italian and Czech subjects. The study was performed in healthy subjects of Italian (n=131) and Czech (n=84) origins. In all subjects routine biochemistry work-ups were performed; additionally, plasma oxysterols and the peroxyl radicals scavenging activity (PERSA) of the sera were determined. Close relationship of serum bilirubin and uric acid to markers of oxidative stress was observed in both examined populations. Compared to the Czechs, the Italian population showed higher plasma concentrations of both oxysterols (7OxCH: 3.6 vs. 6.0 ng/ml, p<10−6; 7BCH: 5.3 vs. 8.6 ng/ml, p<10−6), lower PERSA (p<10−6), and lower serum concentrations of bilirubin and uric acid (p<10−6 in both cases). The dietary patterns of the Italian population did not match the Mediterranean style, but was more similar to the Continental type of diet, presumably due to non-adherence to a Mediterranean diet.