Quantitative data on the magnitude of the systemic inflammatory response and its effect on carotenoids status based on plasma measurements

SummaryBackground & aimPlasma concentrations of carotenoids are decreased in association with the systemic inflammatory response and as a result do not necessarily indicates deficiency. Therefore, the aim of the present study was to examine the magnitude of systemic inflammatory response effect on plasma carotenoids concentration in a large cohort and to provide guidance on the interpretation of routine clinical results.MethodsBetween December 2005 and December 2010, the results (1665 blood samples from 1074 patients) of a carotenoid screen (lutein, lycopene, α-carotene and β-carotene), cholesterol and CRP concentrations, a marker of the severity of systemic inflammation, were extracted from a laboratory database. Plasma carotenoid concentrations were categorised according to an incremental increase in CRP concentrations.ResultIn 1074 patient samples, with the exception of α-carotene (that had median concentrations at the limit of detection), all carotenoids showed a significant trend of decreasing plasma concentrations as CRP concentrations increased. For lutein, lycopene and β-carotene, the decrease was significant when CRP concentrations were modestly elevated (between 20 and 40 mg/L). CRP concentrations of >80 mg/L were associated with the largest decrease in plasma carotenoid concentrations (p < 0.001). These trends remained when the carotenoids were adjusted for cholesterol.ConclusionThe clinical interpretation of plasma carotenoids requires knowledge of the magnitude of the systemic inflammatory response even after adjustment for cholesterol. A reliable clinical interpretation can be made only for plasma lutein, lycopene and β-carotene if the CRP is less than 20 mg/L. Where CRP is greater than 20 mg/L low plasma values are difficult to interpret and may be the first warning sign of carotenoid insufficiency.