Association of B vitamins status and homocysteine levels in elderly Taiwanese

To investigate the relationship between homocysteine (Hey) and B vitamins status in the Taiwanese elderly population, an analysis was made of the plasma Hey levels in elderly persons. The study sample was taken from the Elderly Nutrition and Health Survey in Taiwan (1999-2000)(Elderly NAHSIT) and included 1094 males and 1135 females aged 65-90 years. The results showed that average plasma Hey was 13.3 +/- 0.6 mu mol/L for males and 10.6 +/- 0.7 mu mol/L for females. The average plasma Hey levels of males from all age groups were significantly higher than those of females, and significantly increased with age (P trend <0.0001). The overall prevalence of hyperhomocysteinemia (Hey >15 mu mol/L) was 23.4% for elderly males and 11.2% for elderly females, and this also increased with age (P trend <0.0001). In subjects with normal renal function, folate, vitamin B-2, B-6, and B-12 status were significantly lower in males with byperhomocysteinemia, while only folate and vitamin B-12 were significantly lower in females with hyperhomocysteinernia. Further analysis suggested that folate, vitamin B-6 or B-12 insufficiency were associated with hyperhomocysteinemia in both sexes, while vitamin B-2 insufficiency was significantly associated only in males. In elderly persons with adequate folate, vitamin B-6, and B-12 status, there was no significant association between vitamin B-2 and hyperhomocysteinemia. This association occurred only in those who had concurrent poor folate, vitamin B-6, or B-12 status. The strength of the association between vitamin B-12 insufficiency and hyperhomocysteinernia was not affected by simultaneous vitamin B-2 or B-6 insufficiency, but increased about 3-fold when combined with folate. This suggests that poor folate and vitamin B-12 status has a synergistic effect on the risk of hyperhomocysteinema in the elderly, as did a poor folate and vitamin B-6 status. Therefore, maintaining adequate vitamin B-12 status and avoiding multiple B vitamin insufficiency, especially that of folate and vitamin B-12 or B-6, should be emphasized as an important measure for reducing plasma Hey levels among elderly Taiwanese.