부산대학교 도서관

Background and purpose: A statistically significant increase of plasma total homocysteine (tHcy) has been reported among healthy subjects≧age 50 versus subjects ＜ age 50. Whether the influence of plasma folate and vitamin B12 on plasma tHcy varies between age subgroups remains unclear. The aim of this study was to investigate if the age-related difference in the effect of vitamin status on plasma tHcy levels exists in Taiwanese subjects. Methods: Healthy subjects with normal hepatic and renal functions and no history of vascular thrombosis were recruited for the purpose of measuring plasma levels of tHcy, folate and vitamin B12. The relationship between plasma tHcy level and its potential determinants was examined using multiple linear regression. Results: One hundred and nineteen healthy subjects (67 males and 52 females) whose mean age was 49.6 years (range, 15-85 years) were investigated. In the young subgroup≧age 50 (n=62), the positive association between age and plasma tHcy was not significant (P=0.691). In the old subgroup age 50 (n=57), plasma tHcy increased with age (P=0.001) and with decreasing plasma folate levels (P=0.010); the effects of gender and vitamin B12 on plasma tHcy were not significant (P=0.310 and P=0.288, respectively). After adjustment for gender, a significant age-related increase in plasma folate was noted in the overall sample analysis (P＜0.001), but this association was not significant in the old subgroup (P=0.388). Conclusion: A significant elevation in plasma tHcy exists only in the middle-aged and old population. Plasma folate is more significant than vitamin B12 as a nutritional determinant of plasma tHcy in this population.