[Association of Angiotensin I-converting Enzyme Gene Polymorphism with ACE and PAI-1 Levels in Guangdong Chinese Han Patients with Essential Hypertension]

Objective: To 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.

Methods: Polymerase 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.

Results: The 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).

Conclusion: The 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.