Antioxidant status and the risk of elevated C-reactive protein 12 years later

Low-grade inflammation is an independent risk factor for cardiovascular disease. Relationships between the antioxidant status and inflammatory biomarkers could give new insights into cardiovascular disease prevention. We investigated long-term associations between the antioxidant nutrient (vitamin C, α-tocopherol, β-carotene) status and C-reactive protein (CRP) in a population-based cohort.

Subjects included in the French SU.VI.MAX trial study who had available data on baseline (1994-1995) blood nutrient concentrations and CRP measurements 12 years later (2007-2009) were included. Associations between baseline antioxidant circulating concentrations and elevated CRP (>3 mg/l) were investigated in multivariate logistic regression models. Subgroup analyses were performed according to gender, supplementation group of the initial trial, smoking status, and alcohol intake.

Serum α-tocopherol (n = 2,060) and vitamin C (n = 1,719) concentrations [odds ratio (OR) and 95% confidence interval (95% CI) quintile 5 vs. 1: OR 1.10 (95% CI 0.71-1.73), p for trend = 0.533, vs. OR 0.79 (95% CI 0.48-1.29), p for trend = 0.121, respectively] were not associated with elevated CRP concentrations. The β-carotene status (n = 2,048) was inversely associated with elevated CRP [adjusted OR quintile 5 vs. 1: OR 0.61 (95% CI 0.38-0.98), p for trend = 0.01]. Subgroup analyses showed that associations were stronger in women (p for trend = 0.004), never smokers (p for trend = 0.009) and subjects in the supplementation group (p for trend = 0.002).

Our results suggest that the β-carotene status may be inversely associated with low-grade inflammation in the long term.