Background: Critically-ill patients have low circulating concentrations of vitamin antioxidants. The functional significance of such reductions is not clear.
Aims: To determine whether the presence of a systemic inflammatory response was associated with reduced circulating alpha-tocopherol and carotenoid concentrations and an increase in lipid peroxidation as evidenced by malondialdehyde.
Methods: Healthy controls (n=24) and critically-ill patients (n=43) had circulating concentrations of C-reactive protein, cholesterol, triglycerides, malondialdehyde, alpha-tocopherol, lutein, lycopene, alpha- and beta-carotene measured during ITU stay.
Results: In the critically-ill group circulating concentrations of C-reactive protein and malondialdehyde were significantly higher (P<0.05) and cholesterol, triglyceride, alpha-tocopherol, lutein, lycopene, alpha- and beta-carotene were all significantly lower (P<0.01) compared with the control group. In the critically-ill group alpha- and beta-carotene were below detection limits for many patients. After adjusting for cholesterol, lycopene concentrations remained significantly lower (P<0.001) compared with the control group. In the critically-ill patients circulating concentrations of C-reactive protein and malondialdehyde were significantly correlated (r=0.502,P<0.01).
Conclusions: The systemic inflammatory response is associated with increased lipid peroxidation and low carotenoid concentrations indicating that inflammation driven breakdown of carotenoids is an important factor in lowering circulating carotenoid concentrations in the critically-ill patient.