Associations of methylenetetrahydrofolate reductase C677T polymorphism with markers of subclinical atherosclerosis: The Cardiovascular Risk in Young Finns Study

Abstract

Objective. To study whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism or serum homocysteine concentration is associated with carotid artery intima media thickness (IMT), carotid artery compliance (CAC) or brachial artery flow mediated dilatation (FMD) in a healthy Finnish adult population. Methods. Cross‐sectional data obtained in 2001 for the Cardiovascular Risk in Young Finns Study were used. Carotid artery IMT, CAC and brachial FMD were measured by ultrasound and serum homocysteine concentrations using a commercial immunoassay kit. We studied 1,440 subjects (aged 24–39 years). Genotyping was performed using the 5′ nuclease TaqMan assay. Results. Homocysteine values differed between genotypes in women and men (ANOVA, p<0.001 for both sex groups): the genotype raised values in the order of CC, CT, TT. There was a significant difference in CAC values between the MTHFR genotypes in men (ANOVA, p = 0.008), and the CC genotype had the lowest values. In multivariate linear regression analysis adjusted for other major coronary risk factors (e.g. age, smoking, body mass index, systolic blood pressure, C‐reactive protein), the association remained significant (R² = 25.8 %, beta = 0.091; p = 0.02). Homocysteine level was directly associated with CAC in the whole population (R² = 18.0 %, beta = 0.012; p = 0.014) and in women (R² = 9.3%, beta = 0.02; p = 0.013), but not in men (R² = 15.2 %, beta = 0.004; p = 0.444). We found no association between homocysteine level or the MTHFR polymorphism and carotid IMT or brachial artery FMD. Conclusions. The findings suggest that the MTHFR polymorphism does not influence IMT or FMD, but that the T allele may have an effect on CAC in men.

• Atherosclerosis
• homocysteine
• methylenetetrahydrofolate reductase
• SNP

Acknowledgements

This study was financially supported by the Academy of Finland (grant nos. 104821, 15486, 53392 and 34316), the Social Insurance Institution of Finland, the Turku University Foundation, the Juho Vainio Foundation, the Emil Aaltonen Foundation (TL), the Medical Research Foundation of the Tampere University Hospital, the Medical Research Foundation of Turku University Central Hospital, the Finnish Foundation of Cardiovascular Research, the Finnish Cultural Foundation, the National Graduate School of Clinical Investigation and the Foundation for the Advancement of Laboratory Medicine. We also thank Ms Nina Peltonen for her skilful technical assistance and the other researchers of the Cardiovascular Risk in Young Finns study group for collecting the clinical material.