Original Contribution A reduction in alcohol consumption is associated with reduced plasma F 2 -isoprostanes and urinary 20-HETE excretion in men

There is considerable evidence that chronic moderate-to-high alcohol consumption increases blood pressure. The mechanisms by which this occurs are not clear. Alcohol consumption can induce oxidative stress and cytochrome P450 (CYP450) isoforms that are associated with oxidative stress and may influence vascular tone. To study the role of such mechanisms we examined whether reducing alcohol intake in moderate-to-heavy drinkers (40–110 g/day) resulted in changes in urinary excretion of 20-HETE, a CYP450 metabolite of arachidonic acid, and plasma and urinary F2-isoprostanes as markers of lipid peroxidation. After a 4-week run-in period during which healthy men maintained their usual drinking pattern they were randomized to a two-way crossover intervention study. In each of the 4-week treatment periods subjects either substituted their usual alcohol intake with a 0.9% alcohol beer or maintained their usual alcohol intake. Plasma and urinary F2-isoprostanes and urinary 20-HETE were measured by gas chromatography mass spectrometry, and serum γ-glutamyl transpeptidase (γ-GT) was measured as a biomarker of alcohol consumption, at the end of each study period. Sixteen healthy men age 51.0±2.7 years and with a BMI of 26.4±0.61 kg/m 2 completed the study. The reductions in alcohol intake (72.4±5.0 vs 7.9±1.6 g/day, p<0.001) and serum γ-GT (geometric mean 24.4 U/L (95% CI 19.7, 30.2) vs 18.6 U/L (95% CI 15.5, 22.2, p<0.01) were accompanied by a significant fall in blood pressure as well as urinary 20-HETE excretion (158±23 vs 109±19 pmol/mmol creatinine, p<0.001) and plasma F2-isoprostanes (3438±158 vs 2929±145 pmol/L, p=0.01). A substantial reduction in alcohol consumption in healthy men lowered plasma F2-isoprostanes and urinary 20-HETE. Increased oxidative stress and 20-HETE production may be linked, at least in part, to the pathogenesis of alcohol-related hypertension.