Antioxidant Vitamin Intake and LOX-Index in Japanese Municipal Workers

Antioxidant vitamin intake has been reported to be associated with decreased risk of cardiovascular diseases. To date, however, no study has examined the association between antioxidant vitamin intake and LOX-index, a predictive biomarker of cardiovascular disease. We investigated the cross-sectional association between antioxidant vitamin (α-carotene, β-carotene, α-tocopherol, and vitamin C) intake and LOX-index in Japanese municipal workers. Participants were 346 workers (171 men and 175 women aged 19-71 y) who received a health check-up and participated in a nutrition and health survey. Antioxidant vitamin intake was assessed using a validated brief self-administered diet history questionnaire. LOX-index was calculated by multiplying serum concentrations of the soluble form of lectin-like oxidized LDL receptor 1 by those of LOX-1 ligands containing apolipoprotein B. Multiple regression analysis was used to estimate the geometric mean of LOX-index according to tertile of each antioxidant vitamin intake. Overall, α-carotene, β-carotene, α-tocopherol, and vitamin C intake were not associated with LOX-index. However, in stratified analyses by sex, geometric means of LOX-index tended to decrease with antioxidant vitamin intake in women, but not in men. The geometric means of LOX-index for the lowest through highest tertile of α-carotene intake were 771 (604-984), 639 (511-799), and 564 (469-677) (p for trend=0.07). Our results suggest that there is no association between antioxidant vitamin intake and LOX-index in Japanese workers. The suggestive inverse association between antioxidant vitamin intake and LOX-index in women warrants further investigation.