Influence of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, B vitamins and other factors on plasma homocysteine and risk of thromboembolic disease in Chinese.
BACKGROUND
Thromboembolic disease is a major cause of morbidity and mortality in many countries. Our previous study found that Chinese subjects carried the same polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene as described in Western studies. The aim of the present study was to determine the influence of MTHFR polymorphism, B vitamins and other factors on plasma homocysteine (Hcy) levels and risk of thromboembolic disease in Chinese.


METHODS
One hundred and six subjects were enrolled into the study. They were categorized into 4 groups: healthy individuals (n = 42); those with diabetes mellitus (n = 20); those with deep vein thrombosis (DVT) (n = 11); and those with coronary artery disease (CAD) (n = 33). Plasma levels of folic acid, vitamins B6 and B12, Hcy, and fasting blood sugar were measured; total cholesterol, triglycerides, complete blood count, and 677 C-->T mutation in MTHFR were determined.


RESULTS
Plasma Hcy was lowest in the healthy subjects, higher in diabetics, followed by patients with DVT, and highest in patients with CAD (p < 0.001, ANOVA). MTHFR C677T polymorphism was the common factor affecting plasma logHcy levels in all 4 groups of subjects. Triglycerides affected plasma logHcy in the CAD patients. For the 4 groups as a whole, MTHFR polymorphism, triglycerides, and vitamin B12 were the most significant factors influencing plasma Hcy.


CONCLUSIONS
We suggest that high plasma Hcy is an important risk factor for CAD. Other factors including MTHFR polymorphism, vitamin B12, triglycerides, total cholesterol, and gender might affect Hcy levels in different diseases and conditions.
Ho
Chao-Hung
CH
Division of Hematology, Taipei Veterans General Hospital, 201, Section 2, Shih-Pai Road, Taipei 112, Taiwan, ROC. chho@vghtpe.gov.tw
Kuo
Benjamin Ing-Tiau
BI
Kong
Chi-Woon
CW
Chau
Wing-Keung
WK
Hsu
Hui-Chi
HC
Gau
Jyh-Pyng
JP
Yu
Yuan-Bin
YB
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003327:Coronary Disease / Q000209:etiology; D005260:Female; D005492:Folic Acid / Q000097:blood; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013923:Thromboembolism / Q000209:etiology*; D014805:Vitamin B 12 / Q000097:blood*; D025101:Vitamin B 6 / Q000097:blood*
D006710:Homocysteine; D025101:Vitamin B 6; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12