Association of Mean Arterial Blood Pressure with Plasma Total Homocysteine level, but Not with the Common C677T MTHFR Gene Mutation in Postmenopausal Iranian Women

High plasma total homocystein (tHcy) level, as a source of free radicals, hydrogen peroxide may affect vascular resistance via changes in endothelial cell function. This study was designed to investigate the possible indirect effect of Hcy and common C677T Methylentetrahydrofolate Reductas (MTHFR) gene mutation (a mutant genotype revealed to be accompanied with high plasma Hcy level) on the mean arterial blood pressure (MABP). Materials and Methods: From among 280 postmenopausal women selected on the basis of simple randomized sampling, 266 women participated in this study. Ninety-Five were known cases of hypertension under anti-hypertensive therapy with controlled blood pressure and 171 were normotensive subjects. Anthropometrics, blood pressure, plasma tHcy, plasma folic acid and vitamins B12 as well as C677T mutation in MTHFR gene were assessed for each postmenopausal female. Results: MABP was positively and significantly associated with plasma tHcy level(r=0.230, P=0.003) but not with the common C677T MTHFR gene mutation. In regression analysis, plasma tHcy was the only predictor of MABP (R2=0.05, P=0.004). High plasma tHcy level increased hypertension risk in comparison to normal plasma tHcy level (OR=3.11, CI=1.07-9.18) whereas the mutant MTHFR genotype, TT allele, in comparison to the wild MTHFR genotype, CC allele, did not. Conclusions: Mean arterial blood pressure was significantly associated with plasma tHcy level but not with the common C677T MTHFR gene mutation.