The C677T methylenetetrahydrofolate reductase polymorphism influences the homocysteine-lowering effect of hormone replacement therapy.

Elevated homocysteine is an independent risk factor for cardiovascular disease and has been associated with a common C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene. Estrogen use has been shown to reduce homocysteine concentrations, suggesting that this might contribute to the cardiovascular benefit of hormone replacement therapy. We examined 90 postmenopausal women to determine if MTHFR genotype affected the response of homocysteine to hormone replacement therapy. Women with the TT genotype did not show decreased homocysteine in response to hormone replacement therapy as demonstrated for women with the CC genotype and may receive decreased cardiovascular benefits from hormone replacement therapy. Copyright 1999 Academic Press.