Sex-specific association of plasma vitamin E with homocysteine concentrations in Chinese middle-aged and older men and women: evidence from pooled population-based study.

PURPOSE: Blood homocysteine (Hcy) concentrations have become a sensitive predictor of the development of cardiovascular disease. Few studies have reported the relationship between plasma vitamin E and Hcy. We aim to conduct an sex- and age-stratified investigation of the association between vitamin E status and Hcy concentrations in a large nationwide sample in China.

METHODS

We conducted a cross-sectional study including 15,842 Chinese adults. The exposure variable was plasma vitamin E. The outcome variables included Hcy concentrations and hyperhomocysteinemia. Multiple linear models and multivariable logistic regression were performed to evaluate the relation between plasma vitamin E and Hcy. Restricted cubic spline was conducted to examine the non-linear relationship.

RESULTS

In men, the association between plasma vitamin E and Hcy concentrations suggested an approximately U-shaped pattern (p for nonlinearity < 0.001). Compared with men aged < 65 years with plasma vitamin E concentrations of 8.5-15.9 µg/mL, those with concentrations below 8.5 µg/mL or above 15.9 µg/mL had higher odds of hyperhomocysteinemia (OR: 1.33 (1.10,1.60), p = 0.002; OR: 1.77 (1.25, 2.50), p = 0.001, respectively). In men ≥ 65 years old, plasma vitamin E < 8.4 µg/mL was not significantly associated with hyperhomocysteinemia (OR: 1.06(0.86,1.30), p = 0.589). Among women, age-stratified spline curves generally suggested an L-shaped pattern, with higher plasma vitamin E concentrations associated with lower Hcy concentrations, followed by a plateau in the association.

CONCLUSIONS

Sex-specific associations between plasma vitamin E and Hcy concentrations or hyperhomocysteinemia were found. The spline analyses suggested an approximately U-shaped pattern in men and an L-shaped pattern in women. In contrast to the sex-specific patterns, the association between vitamin E and Hcy were generally consistent across age groups.