Angiotensin-Converting Enzyme Gene Polymorphism and Arterial Hypertension in a Mongolian Population

Abstract

Background: Arterial hypertension (AH) is a major risk factor for cardiovascular morbidity and mortality, with both genetic and environmental factors contributing to its development. The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been investigated as a potential genetic determinant of hypertension; however, evidence in the Mongolian population remains limited. Aim: To determine the distribution of the ACE gene I/D polymorphism and investigate its association with arterial hypertension and cardiovascular risk factors in a Mongolian population. Materials and Methods: A case-control study was conducted between October 2018 and November 2019. A total of 150 participants aged 20–64 years were included, comprising 100 patients with AH and 50 normotensive controls. AH was defined as blood pressure ≥130/80 mmHg or current use of antihypertensive medication. Cardiovascular risk factors were assessed using questionnaires and physical examination. Genomic DNA was extracted from peripheral blood lymphocytes, and the ACE I/D polymorphism in intron 16 was determined using a two-step polymerase chain reaction (PCR). Associations between ACE genotypes and AH were assessed using the chi-square test and multivariable logistic regression. A p value <0.05 was considered statistically significant. Results: Among the 150 participants, 64 (42.7%) were male, and the mean age was 44.2±11.7 years. The frequencies of the II, ID, and DD genotypes were 44.0%, 39.3%, and 16.7%, respectively. No significant difference in genotype distribution was observed between males and females. The frequencies of ID, DD, and II genotypes in the hypertensive and control groups were 39.0% vs. 40.0% (p=0.906), 14.0% vs. 22.0% (p=0.215), and 47.0% vs. 38.0% (p=0.295), respectively. The D-allele frequency was 0.33 in the hypertensive group and 0.42 in the control group, with no statistically significant difference. Participants with AH were older and had significantly higher body mass index, waist circumference, salt intake, alcohol consumption, and blood pressure compared with controls. Conclusions: 1. The I allele of the ACE gene was predominant in the studied Mongolian population. 2. Neither the ACE I/D genotype nor the D allele was significantly associated with arterial hypertension. Traditional cardiovascular risk factors, including older age, excess body weight, abdominal obesity, high salt intake, and inappropriate alcohol consumption, showed stronger associations with hypertension in this population.