Objective: To investigate the association between the alpha-adducin gene G460T, angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphisms and salt-sensitive hypertension and early renal injury in Chinese people.
Methods: The case-control study was performed in 200 essential hypertension (EH) and 200 normal control subjects in China. The 200 EH patients were divided into salt-sensitive(SS= 109) and non-salt-sensitive(NSS= 91) groups according to modified Sullivan's method. The genotypes of alpha-adducin gene were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The ACE genotypes were determined by PCR. The urine microalbum (Alb) in 200 EH subjects was measured by radioactive immunoassay.
Results: (1) A higher frequency of alpha-adducin gene G460T TT in EH patients was observed (P< 0.05). No significant difference of the ACE gene I/D polymorphism was found between the EH patients and normal control (P> 0.05). There were significant differences in the alpha-adducin gene TT genotype and combined genotype of TT+ II between SS and NSS subjects (P< 0.05). (2) The levels of urine Alb/Cr in SS patients were significantly higher than that in NSS patients (P< 0.05); in SS group, the levels of urine Alb/Cr in ACE II and alpha-adducin gene TT genotypes were higher than that in ACE ID, DD genotype and alpha-adducin gene GT and GG genotypes. The levels of urine Alb/Cr in the group of alpha-adducin gene TT+ ACE II combined genotype were higher than that in other combined genotypes (P< 0.05).
Conclusion: The alpha-adducin gene TT genotype or combined with ACE II are significantly associated with SS hypertension. The alpha-adducin gene TT and ACE II genotypes might be genetic susceptibility factors to hypertension accompanying renal injury.