Ni Juan, Zhang Ling, Zhou Tao, Xu Wei-Jiang, Xue Jing-Lun, Cao Neng, Wang Xu
Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Kunming, China; Key Laboratory of Yunnan Province for Biomass Energy and Environmental Biotechnology, Kunming, China; School of Life Sciences, Yunnan Normal University, Kunming, China.
Institute of Genetics, Fudan University, Shanghai, China.
J Chin Med Assoc. 2017 Mar;80(3):147-153. doi: 10.1016/j.jcma.2016.07.005. Epub 2017 Jan 13.
An increased serum total homocysteine (tHcy) concentration is typically associated with genetic defects involved in Hcy metabolism or related nutritional deficiencies. In this study, the combined effects of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and folate and vitamin B12 deficiency on serum total Hcy (tHcy) levels were evaluated in a healthy Chinese population in Yunnan Province, China.
The MTHFR C677T polymorphism was genotyped in 330 volunteers (164 men and 166 women) using polymerase chain reaction-restriction fragment length polymorphism analysis. Folate, vitamin B12, and tHcy concentrations were determined by corpuscle immune chemiluminescence assays. The tHcy concentration was determined using an enzymatic assay.
Significant negative correlations (p<0.001) were observed between the serum levels of tHcy and folate (r=-0.252) and vitamin B12 (r=-0.243). Men had significantly higher serum tHcy concentrations than women (p<0.001). Individuals with the MTHFR TT genotype had significantly higher serum tHcy concentrations than individuals with the CC and CT genotypes (p<0.001). The folate level of red blood cells was significantly increased in individuals with the TT genotype than in individuals with the CC genotype (p<0.05). Moreover, in the low vitamin group, the serum tHcy level was significantly correlated with the levels of folate (r=-0.334, p=0.001) and vitamin B12 (r=-0.212, p=0.046).
The MTHFR C677T polymorphism, folate deficiency, and B12 deficiency were significantly associated with elevated serum tHcy levels. Among these three factors, folate deficiency had the greatest contribution to the serum tHcy concentration, followed by (in order of decreasing effect) MTHFR C677T and vitamin B12 deficiency. Thus, folic acid and vitamin B12 supplementation could help prevent diseases associated with tHcy accumulation, especially in individuals with the MTHFR 677TT genotype.
血清总同型半胱氨酸（tHcy）浓度升高通常与同型半胱氨酸代谢相关的基因缺陷或相关营养缺乏有关。在本研究中，在中国云南省的健康人群中，评估了亚甲基四氢叶酸还原酶（MTHFR）C677T多态性以及叶酸和维生素B12缺乏对血清总同型半胱氨酸（tHcy）水平的综合影响。
采用聚合酶链反应-限制性片段长度多态性分析对330名志愿者（164名男性和166名女性）的MTHFR C677T多态性进行基因分型。通过血细胞免疫化学发光测定法测定叶酸、维生素B12和tHcy的浓度。使用酶促测定法测定tHcy浓度。
观察到血清tHcy水平与叶酸（r = -0.252）和维生素B12（r = -0.243）之间存在显著负相关（p < 0.001）。男性的血清tHcy浓度显著高于女性（p < 0.001）。MTHFR TT基因型个体的血清tHcy浓度显著高于CC和CT基因型个体（p < 0.001）。TT基因型个体的红细胞叶酸水平显著高于CC基因型个体（p < 0.05）。此外，在低维生素组中，血清tHcy水平与叶酸水平（r = -0.334，p = 0.001）和维生素B12水平（r = -0.212，p = 0.046）显著相关。
MTHFR C677T多态性、叶酸缺乏和维生素B12缺乏与血清tHcy水平升高显著相关。在这三个因素中，叶酸缺乏对血清tHcy浓度的影响最大，其次（按影响程度递减顺序）是MTHFR C677T和维生素B12缺乏。因此，补充叶酸和维生素B12有助于预防与tHcy积累相关的疾病，尤其是MTHFR 677TT基因型个体。
