A power analysis revealed that, for α = 0.05, our study had a power to detect differences across cases and controls of 0.85 for the C-carrying genotype of T1880C, 0.93 for the A-carrying genotype of C602A, and 0.89 for the C-carrying genotype of T1559C. The genotype frequencies of C602A were significantly different (P = 0.005) between EH and NT groups, and the C-allelic frequency was also significantly different (P = 0.001; Table 3). A comparison of dominant versus recessive models (CC + CA vs. AA, or AA + CA vs. CC) revealed that significant differences persisted (P = 0.004 and P = 0.02 for dominant and recessive models, respectively). Interestingly, when subgrouped by sex, these indexes were significantly different in male NT and EH groups, but not in female NT and EH groups. The additive model of the T1559C genotype was not different between EH and NT groups (P = 0.39), but it was different between male EH and NT groups (P = 0.046) and female EH and NT groups (P = 0.045). The CC + TC versus TT frequency of T1559C was also different in a recessive model of male EH and NT groups (P = 0.02). Furthermore, there was a significant interaction between E-selectin and gender (Pinteraction = 0.02 for C602A and 0.04 for T1559C), but there was no significant interaction between the E-selectin genotypes and other indexes. As for the SNP T1880C, neither genotype distribution nor allelic frequency was obviously different between hypertensive patients and healthy normotensive subjects.