MTHFR and hypertensive disorder: When included in the multivariable model, age (65–74 years, OR: 2.219, 95% CI: 1.074 to 4.585, p = 0.031; ≥75 years, OR: 2.714, 95% CI: 1.185 to 6.214, p = 0.018), history of hypertension (OR: 2.009, 95% CI: 1.203 to 3.353, p = 0.008), HHcy (OR: 1.874, 95% CI: 1.030 to 3.408, p = 0.040), MTHFR TT genotype (TT genotype, OR: 2.786, 95% CI: 1.233 to 6.295, p = 0.014), WMH (Fazekas grade 2, OR: 2.518, 95% CI: 1.208 to 5.250, p = 0.014; Fazekas grade 3, OR: 3.067, 95% CI: 1.225 to 7.680, p = 0.017) and lacunes (OR: 2.875, 95% CI: 1.518 to 5.445, p = 0.001) remained significant (Table 6).