CHRNA3 and hypertensive disorder: After adjusting for marital status, family income, family history of hypertension, physical exercise and age at smoking initiation, heavy smokers with the homozygous mutant TT genotype of CHRNA3 rs6495308 were found to have the highest risk of hypertension (OR = 2.44, 95% CI = 1.27–4.68) (Table 2 and Figure 2).