Association Between the Angiotensin-Converting Enzyme I/D Polymorphism and Risk of Cerebral Small Vessel Disease: A Meta-Analysis Based on 7186 Subjects

Angiotensin-converting enzyme insertion/deletion gene polymorphism and the progression of cerebral microbleeds

Background and purpose

The angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism has been studied as a genetic candidate for cerebral small vessel disease (CSVD). However, no previous study has evaluated the relationship between the ACE I/D polymorphism and cerebral microbleed (CMB), an important CSVD marker. We evaluated the association between ACE I/D polymorphisms and 2-year changes in CMBs.

Methods

The CHALLENGE (Comparison Study of Cilostazol and Aspirin on Changes in Volume of Cerebral Small Vessel Disease White Matter Changes) database was analyzed. Of 256 subjects, 186 participants who underwent a 2-year follow-up brain scan and ACE genotyping were included. Our analysis was conducted by dividing the ACE genotype into two groups (DD vs. ID/II) under the assumption of the recessive effects of the D allele. A linear mixed-effect model was used to compare the 2-year changes in the number of CMBs between the DD and combined ID/II genotypes.

Results

Among 186 patients included in this study, 24 (12.9%) had the DD genotype, 91 (48.9%) had the ID genotype, and 71 (38.2%) had the II genotype. Baseline clinical characteristics and cerebral small vessel disease markers were not different between the two groups (DD vs. ID/II) except for the prevalence of hypertension (DD 66.7% vs. ID/II 84.6%; p = 0.04). A multivariate linear mixed-effects model showed that the DD carriers had a greater increase in total CMB counts than the ID/II carriers after adjusting for the baseline number of CMBs, age, sex, and hypertension (estimated mean of difference [standard error (SE)] = 1.33 [0.61]; p = 0.03). When we performed an analysis of cases divided into deep and lobar CMBs, only lobar CMBs were significantly different between the two groups (estimated mean of difference [SE] = 0.94 [0.42]; p = 0.02).

Conclusion

The progression of CMBs over 2 years was greater in the ACE DD carriers compared with the combined II/ID carriers. The results of our study indicate a possible association between the ACE I/D polymorphism and CMB. A study with a larger sample size is needed to confirm this association.

Association between Interactions among ACE Gene Polymorphisms and Essential Hypertension in Patients in the Hefei Region, Anhui, China

Objective

Essential hypertension (EH) is a common cardiovascular disease that endangers human health. Its pathogenesis is complex and has not been fully elucidated. We explore the association between EH and interactions among polymorphisms of the angiotensin converting enzyme (ACE) gene in the Hefei region, Anhui, China.

Methods

A total of 500 participants (400 hypertensive and 100 normotensive) were included in this study. The polymorphisms were detected via improved multiple ligase detection reaction (iMLDR). To improve the accuracy of prediction, multifactor dimensionality reduction (MDR) was used to analyze the overall effect of interactions among seven loci on the incidence of EH.

Results

The frequencies of polymorphisms in the ACE genes rs12709426, rs4291, rs4309, rs4331, rs4343, rs4459609, and rs4461142 in the EH group were not statistically significantly different from those in the control group. We also found that the single nucleotide polymorphism (SNP) rs12709426 only had a homozygous AA genotype and no polymorphisms. There were no differences in the frequency of genetic polymorphisms between the EH and control groups. The best model explaining the EH group was the combined effect of ACE genes rs4291, rs4309, and rs4461142.

Conclusion

There is an interaction effect among ACE gene loci in EH patients in Hefei region, Anhui, China. Also, the ACE gene SNP rs12709426 only has a homozygous AA genotype and does not show an association with EH.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and risk of ischemic stroke complication among patients with hypertension in the Ethiopian population

Background

Ischemic stroke is a complicated, multifaceted condition brought on by a confluence of vascular, environmental, and genetic variables. The burden of ischemic stroke is currently rising in terms of death, morbidity, and disability worldwide. Genetic variables also play significant roles in the pathophysiology of hypertension and ischemic stroke in addition to the greatest effects of demographic, clinical, and behavioral risk factors. The key functional variation of the ACE gene that has drawn the most interest is the ACE I/D variant. Even though the ACE gene I/D polymorphism has been widely studied, the findings of investigations on the involvement of this polymorphism in ischemic stroke were contradictory and provide conflicting data. The goal of this study was to look into the effect of the ACE gene I/D polymorphism on the risk of ischemic stroke in patients with hypertension.

Methods

A hospital-based case-control study was carried out in 36 cases of patients with hypertensive IS and 36 age- and sex-matched healthy controls. Clinical and biochemical parameters were measured to assess the associated risk factors. The DNA was isolated from blood samples, and the ACE I/D genotypes were identified using polymerase chain reaction and analyzed by agarose gel electrophoresis.

Results

The ACE-DD genotype (OR = 3.71, 95% CI = 1.02-13.5; P < 0.05) and D allele (OR = 2.07, 95% CI = 1.06-4.03; P < 0.05) were significantly more common in patients than in controls, indicating that it is a risk factor for the development of ischemic stroke in hypertensive individuals.

Conclusion

There is a significant correlation between the ACE gene I/D polymorphism and the development of ischemic stroke in patients with a history of hypertension in the Ethiopian population.