20-HETE and F₂-isoprostanes in the metabolic syndrome: the effect of weight reduction

20-Hydroxyeicosatetraenoic acid (20-HETE) is a cytochrome P450 metabolite of arachidonic acid that regulates vascular function and sodium homeostasis. Studies showing an association between 20-HETE excretion, raised BMI, and oxidative stress suggest that 20-HETE may be important in the development of cardiovascular disease in the metabolic syndrome (MetS). We investigated whether 20-HETE and F₂-isoprostanes (markers of oxidative stress) were altered in the MetS before and after weight reduction. A case-controlled comparison of 30 participants with the MetS and matched controls showed that plasma and urinary 20-HETE and F₂-isoprostanes were significantly elevated in the MetS group. There was a significant gender × group interaction such that women with the MetS had higher urinary 20-HETE and F₂-isoprostanes compared to controls (p < 0.0001). In a randomized controlled trial, 42 participants with the MetS were assigned to 16 weeks of weight maintenance or a 12-week weight-loss program followed by 4 weeks weight stabilization. Relative to the weight-maintenance group, a 4-kg loss in weight resulted in a 2-mm Hg fall in blood pressure (BP) but did not alter urinary or plasma 20-HETE or F₂-isoprostanes. 20-HETE and oxidative stress may be important mediators of cardiovascular disease risk in the MetS. Although a 4% reduction in body weight reduced BP, there were no changes in plasma or urinary 20-HETE or F₂-isoprostanes.