Homocysteine and asymmetric dimethylarginine in relation to B vitamins in elderly people
Homocysteine and asymmetric dimethylarginine in relation to B vitamins in elderly people
复制标题
DOI：
10.1007/s00508-011-0002-3
复制
发表时间：
2011-08-01
影响因子：
2.6
通讯作者：
Elmadfa, Ibrahim
中科院分区：
文献类型：
--
作者：
Fabian, Elisabeth;Kickinger, Andrea;Elmadfa, Ibrahim
目的：同型半胱氨酸是一种心血管危险因素，其代谢受某些B族维生素的影响，并与内皮功能障碍有关，可能是由于同型半胱氨酸导致内源性一氧化氮合酶抑制剂不对称二甲基精氨酸(ADMA)积聚，导致NO生物利用度降低所致。在此基础上，我们调查了老年人心血管危险因素同型半胱氨酸和ADMA与维生素B-6、B-12和叶酸的关系。方法：将102名受试者按年龄分为三组：A组(70-74岁，n=48)，B组(75-79岁，n=35)，C组(>；=80岁，n=19)。用高效液相色谱法测定血浆维生素B6，放射免疫法测定血浆维生素B12和叶酸水平。用高效液相色谱法测定血浆同型半胱氨酸浓度，用ELISA法测定ADMA水平。结果：93%的受试者血浆维生素B-6、B-12和叶酸水平正常，67%的受试者血浆中维生素B-12和叶酸的水平适中。这项研究显示，维生素B-6(A>；B，A>；C：P<；0.05)、B-12和叶酸(A>；C：P<；0.05)显著减少，而心血管危险因素同型半胱氨酸(A<；C，B<；C：P<；0.05)和ADMA(A<；B：P<；0.05；A<；C：P<；0.001)显著增加。此外，同型半胱氨酸与维生素B-6、B-12和叶酸呈显著负相关(p<；0.01)，与ADMA呈显著正相关(p<；0.01)。结论：本研究观察到的同型半胱氨酸与ADMA显著相关可能是降低NO生物利用度从而导致内皮功能障碍的重要机制。由于维生素B-6、B-12和叶酸与血浆同型半胱氨酸密切相关，这些维生素可能间接影响老年人的血管内皮功能和心血管风险。
Objective: Homocysteine is a cardiovascular risk factor, its metabolism is influenced by certain B vitamins and it is associated with endothelial dysfunction probably due to impaired bioavailability of NO caused by homocysteine-induced accumulation of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase. On this basis, we investigated the cardiovascular risk factors homocysteine and ADMA in relation to vitamins B-6, B-12 and folate in elderly people.Methods: A total of 102 subjects were recruited and divided into three groups according to age: A (70-74y, n = 48), B (75-79y, n = 35) and C (>= 80y, n = 19). Plasma levels of vitamin B-6 were determined with HPLC, vitamin B 12 and folate by RIA. Plasma concentrations of homocysteine were analyzed with HPLC and levels of ADMA were measured by ELISA.Results: Plasma levels of vitamins B-6, B-12 and folate were found to be adequate in 93, 67 and 55% of participants, respectively. This study showed a significant age-associated decrease in vitamins B-6 (A > B, A > C: p < 0.05), B-12 and folate (A > C: p < 0.05) in parallel to a significant age-related increase in the cardiovascular risk factors homocysteine (A < C, B < C: p < 0.05) and ADMA (A < B: p < 0.05; A < C: p < 0.001). Moreover, homocysteine was significantly negatively (p < 0.01) related to vitamins B-6, B-12 and folate, and significantly positively (p < 0.01) correlated to ADMA.Conclusions: The significant correlation between homocysteine and ADMA observed in this study may be an important mechanism decreasing NO bioavailability and so causing endothelial dysfunction. Due to the significant relation of vitamins B-6, B-12 and folate to plasma homo-cysteine, these vitamins may thus indirectly influence endothelial function and cardiovascular risk in elderly people.