MTHFR and hypertensive disorder: In ANCOVA models adjusted for age, sex, smoking and drinking status, history of hypertension, FPG levels, status of FA fortification and family history, patients with ARC had lower activity of MTHFR (338.9 ± 35.8 U/L vs 369.6 ± 52.1 U/L, P < 0.001, Table 7) and higher levels of tHcy (12.3 ± 2.8 μmol/L vs 10.8 ± 1.9 μmol/L, P < 0.001, Table 7) than our control group.