β-Carotene Concentration and Its Association with Inflammatory Biomarkers in Spanish Schoolchildren

AIM: To examine the correlation between inflammatory biomarkers and plasma β-carotene levels in children. METHODS: A total of 564 Spanish schoolchildren aged 9-12 were observed and studied. Plasma β-carotene levels were assessed by HPLC. A β-carotene level <4.83 µg/dL (0.09 µmol/L) was considered deficient. Plasma tumour necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were measured by immunoenzyme assays. Serum high-sensitivity C-reactive protein (hs-CRP) was tested by immunonephelometry. RESULTS: Subjects who were β-carotene-deficient (23.1% of the studied children) had higher IL-6 levels than subjects with normal β-carotene concentrations. The log-IL-6 and log-hs-CRP concentrations, but not the log-TNF-α level, were strongly and inversely related to the plasma log-β-carotene level (taking into account log-age, energy intake, log-triglycerides, gender, log-body mass index, log-β-carotene intake, energy from lipids and cholesterol as covariables). When the 3 inflammatory biomarkers were introduced into the regression model along with the corresponding covariables, only the log-IL-6 level was related to the plasma log-β-carotene level (β = -0.505 ± 0.078; p < 0.001). CONCLUSIONS: Inflammatory status, in particular IL-6 levels, appears to be negatively associated with plasma β-carotene levels in schoolchildren.