Investigation of effects on carotid intima media thickness of mthfr gene variations and homocysteine levels in patients with hypertension

Hypertension (HT) is one of the most important modifiable risk factors for cardiovascular disease. Lowering of blood pressure through antihypertensive drugs and lifestyle changes can reduce target organ damage and prevent disease outcomes. Atherosclerosis is a pathological condition that results in the plaque formation on the arterial wall, which limits the flow of blood to the target organ and leading to serious problems such as stroke and paralysis as the plaque grows. Previous studies suggest that carotid intima media thickness (CIMT) is a good non-invasiv biomarker for atherosclerotic and cardiovascular diseases. Homocysteine is a non-protein coding, non-dietary and sulphurous amino acid that is found in low micromolar concentrations in the serum. One of the most known enzyme that plays an important role in homocysteine metabolism is 5,10-methylene tetrahydrofolate reductase (MTHFR) C677T and A1298C also the gene variations of this enzyme is associated with the diseases such as cancer, myocardial infarction, diabetes, stroke, renal disease, congenital defects, coronary heart disease, depression and schizophrenia. Although MTHFR variations and hyperhomocysteinemia are associated with atherosclerosis and coronary artery disease, the results of previous studies conducted in relation to the pathogenesis of hypertension are contradictory. In the our thesis project, we were aimed to investigate the possible effect of this variations on homocysteine serum level and hypertension by determining MTHFR C677T and A1298C polymorphisms and homocysteine serum level. For this purpose, 80 hypertension patients and 67 healthy controls were included to this study. In order to determine the polymorphisms of MTHFR C677T and A1298C polymorphisms, the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was performed and serum homocysteine levels were measured by enzyme-linked immunosorbent assay (ELISA) technique. As a result, there was a statistically significant difference between the patient and control groups in terms of MTHFR C677T polymorphism (p <0,001), but not in terms of MTHFR A1298C polymorphism (p = 0,058). Serum homocysteine levels were not significantly different between the patient and control groups (p = 0.065). In both groups, there was a significant difference between MTHFR C677T allele frequency and homocysteine levels (p=0,027), but there was no significant difference between MTHFR A1298C allele frequency and serum homocysteine levels (p = 0,996). In conclusion, MTHFR C677T polymorphism was associated with hypertension but not with homocysteine levels. There was no statistical significance between CIMT values and MTHFR C677T T allele, A1298C C allele and homocysteine levels in the patient groups. Key Words: Hypertension, gene polymorphism, carotid-intima media thickness, homocysteine, MTHFR