Serum carotenoids and vitamins in relation to markers of endothelial

Background: Endothelial cell dysfunction may be related to an increase in cellular oxidative stress. Carotenoids and vitamins could have an antioxidant-mediated tempering influence on endothelial function and inflammation, thereby reducing the risk of atherosclerosis. Methods: We measured serum carotenoids, α$-tocopherol and Vitamin C concentrations in 379 subjects sampled from the general population. High-sensitive C-reactive protein (CRP), fibrinogen (Fbg) and leukocytes were measured as markers of inflammation. Furthermore, soluble intercellular adhesion molecule-1 (sICAM-1) and flow-mediated vasodilation (FMD; n=165) were measured as markers of endothelial function. Relationships between serum carotenoids and vitamins and markers of endothelial function and inflammation were analysed after adjustment for confounding. Results: In the total study group, lutein and lycopene were inversely related to sICAM-1 with regression-coefficients of −0.38 $±$ 0.19 (p=0.04) and −0.16 $±$ 0.08 (p=0.04) per 1 μmol/l, respectively. $β$-Carotene was inverse related to leukocytes (−0.23 $±$ 0.07; p=0.007) and CRP (−1.09 ± 0.30; p=0.0003) per 1 $μ$mol/l. Vitamin C was inverse related to CRP (−0.01 $±$ 0.005; p=0.04) per 1 $μ$mol/l, whereas $α$-tocopherol was positively related to CRP (0.03 $±$ 0.01; p=0.02) per 1 $μ$/l. Zeaxanthin was inversely related to FMD (31.2 $±$ 15.3; p=0.04) per 1 $μ$mol/l. Conclusion: The inverse relations between carotenoids, Vitamin C and sICAM-1, CRP and leukocytes may help to explain the possible protective effect of carotenoids and Vitamin C on atherosclerosis through an influence on inflammatory processes and endothelial function.