Objective: To assess the interaction of the MTHFR C677T polymorphism with changes in lipid and glucose metabolism effected by oral hormone replacement therapy (HRT) in postmenopausal women.
Methods: In this open-label, prospective, interventional study, parameters of lipid and glucose metabolism, as well as homocysteine, were assessed in 97 postmenopausal women at baseline and 1 year after the initiation of HRT. Participants were stratified into three subgroups, according to the MTHFR C677T polymorphism (wild-type: CC genotype; heterozygous: CT genotype; homozygous for the mutant variable: TT genotype).
Results: The TT genotype was associated with an elevation of total and low density lipoprotein (LDL) cholesterol, while CT and CC genotypes were associated with a reduction of total cholesterol and LDL cholesterol after 1 year of HRT (p = 0.032 for total cholesterol and p = 0.002 for LDL cholesterol). Women with the TT genotype had higher glucose levels in contrast to women with the CC genotype who had lower glucose levels after 1 year of HRT (p = 0.011). Additionally, CC carriers under HRT had a significant elevation of apolipoprotein A1 levels (p = 0.018), contrarily to CT and TT genotypes.
Conclusion: While HRT was associated with favorable changes in lipid and metabolic parameters in carriers of the CC genotype, this effect was not evident in carriers of the T allele. The MTHFR C677T polymorphism may modify the effect of HRT on lipid and metabolic parameters in postmenopausal women.