The I/D polymorphism of the angiotensin converting enzyme gene as a risk factor for ischemic stroke in patients with essential hypertension in Kyrgyz population

OBJECTIVES
We investigated the association of the I/D polymorphism of the angiotensin converting enzyme (ACE) gene with essential hypertension (EH) and ischemic stroke in Kyrgyz male subjects.

STUDY DESIGN
The study included a total of 313 Kyrgyz men, including 180 patients with uncomplicated EH, 69 patients with EH complicated by ischemic stroke, and 64 healthy age-matched controls. All the subjects underwent I/D genotyping and determination of serum ACE activity. Ambulatory blood pressure (BP) monitoring and carotid ultrasound (51 patients) were also performed in patients with EH.

RESULTS
The mean ACE concentration was 23.3±0.7 mU/ml/min for II, 32.2±0.9 mU/ml/min for ID, and 38.8±2.3 mU/ml/min for DD genotypes. The ID and DD genotypes were associated with significantly higher ACE levels compared to the II genotype (p<0.01 and p<0.0001, respectively). The frequency of the DD genotype in EH patients with ischemic stroke was more than two-fold greater than those with uncomplicated EH (0.31 vs 0.13, p<0.02), and nearly four-fold greater than the control group (0.31 vs 0.09, p<0.02). Patients with ischemic stroke had the highest frequency of the D allele compared to EH patients without stroke and controls (0.56 vs 0.36 and 0.29 respectively, p<0.001). Patients with the DD genotype differed significantly from those with the II or ID genotypes with greater variability of systolic and diastolic BP, more common abnormal night BP profile, and increased carotid intima-media thickness.

CONCLUSION
In the Kirghiz population, the presence of the DD genotype is associated with higher ACE levels and increased risk for ischemic stroke as a complication of EH.