OBJECTIVETo investigate the association between angiotensin I-converting enzyme (ACE) gene and the levels of ACE and PAI-1 in Chinese Han patients with essential hypertension (EH) in Guangdong Province.

METHODSPolymerase chain reaction was used to examine the ACE genotype, colorimetry used to measure the serum ACE level, and spectrophotometric assay performed to examine the plasma PAI-1 level in 115 EH patients and 96 healthy controls in Guangdong Province.

RESULTSThe ACE DD genotype and D allele frequencies were significantly higher in EH group than in the control group (P<0.05), and the EH patients also had significantly higher serum ACE level and plasma PAI-1 level than the control subjects (P<0.01). The serum ACE level was positively correlated with plasma PAI-1 level in both EH group and control group (r=0.7913 and 0.7806, respectively, P<0.01). In EH group, the patients with DD genotype showed significantly higher serum ACE and plasma PAI-1 levels than those with ID and II genotypes (P<0.01), and patients with ID genotype had significantly higher ACE and PAI-1 levels than those with II genotype (P<0.05).

CONCLUSIONThe DD genotype and D allele of ACE gene can be risk factors for essential hypertension in Chinese Han subjects in Guangdong Province, and the EH patients have elevated serum ACE and plasma PAI-1 levels. Increased ACE level due to DD polymorphism may play an important role in elevating plasma PAI-1 level. The genetic variation of ACE contributes to the balance of fibrinolytic pathway, which may be one of the pathological mechanisms linking the ACE I/D genotype and EH.