Association between renin-angiotensin system gene polymorphism and recurrent wheezing in Chinese children: a 4-year follow-up study

Genetically high angiotensin-converting enzyme concentrations causally increase asthma risk: A meta-analysis using Mendelian randomization

Objectives

This meta-analysis aimed to test the association of angiotensin-converting enzyme (ACE) gene I/D polymorphism with asthma risk and circulating ACE changes.

Methods

Public literature retrieval, publication selection, and information extraction were completed independently by two investigators. Effect-size values are expressed as odds ratios (ORs) or standardized mean differences (SMDs) with a 95% confidence interval (95% CI).

Results

Nineteen studies (2,888 patients and 9,549 controls) fulfilled the eligibility criteria. Overall investigations demonstrated that ACE gene I/D polymorphism was significantly associated with asthma risk under allelic (OR, 95% CI: 1.26, 1.08 to 1.48), homozygous genotypic (1.50, 1.09 to 2.06), and recessive (1.53, 1.24 to 1.89) models with moderate heterogeneity (I2 statistic: 64% to 79%). Subsidiary investigations recorded that race, matched status, asthma diagnosis, sample size, and age possibly accounted for the existence of significant heterogeneity. Relative to carriers with the II genotype, those with the DD genotype, ID genotype, and the combination of DD and ID genotypes had significantly higher concentrations of circulating ACE (WMD: 3.13, 2.07, and 2.83 U/L, respectively, p < 0.05). Adoption of Mendelian randomization analyses revealed that one unit increment in circulating ACE concentrations was found to be significantly associated with a 1.14-fold increased risk of asthma (95% CI: 1.02 to 4.24).

Conclusion

We provided strong meta-analytical evidence supporting the causal implication of high circulating ACE concentrations in the development of asthma.

Angiotensin-converting enzyme insertion/deletion polymorphism and susceptibility to pediatric asthma: A meta-analysis

Objective:

The correlation of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism with pediatric asthma risk was assessed in this meta-analysis.

Methods:

PubMed, Web of Science, Embase and CNKI databases were systematically searched for relevant literature, followed by application of odds ratios (OR) along with 95% confidence interval (CI) for determining the strength of relationship.

Results:

Seven articles with 802 cases and 632 controls fulfilled the inclusion criteria. As a result, the ACE I/D polymorphism was related to elevated pediatric asthma risk (D vs I: OR = 1.87, 95% CI = 1.59–2.20; dominant model: OR =1.53, 95% CI = 1.28–1.81; recessive model: OR =1.54, 95% CI = 1.28–1.85; DD vs II: OR =2.95, 95% CI = 2.19–3.98; DI vs II: OR = 0.96, 95% CI = 0.78–1.19). Subgroup analysis stratified by race revealed significant interrelation in Asians.

Conclusion:

This meta-analysis demonstrated that the ACE I/D polymorphism might be related to the risk of pediatric asthma.

Evaluation of angiotensin converting enzyme gene polymorphism and susceptibility to bronchial asthma among Egyptians

BACKGROUND

Angiotensin converting enzyme (ACE) is expressed at high levels in the lungs and plays a role in the metabolism of the endogenous peptides involved in asthma pathogenesis. ACE gene polymorphisms have been reported to be linked to asthma. However, the results are conflicting, with no reported studies on Egyptian asthmatics. We aimed to assess ACE gene polymorphism among Egyptian asthmatics, and to determine its possible association with asthma severity.

METHODS

This case-control study was conducted on 30 adult asthmatic patients, and 30 healthy controls with no history of asthma or atopy. Atopic status among asthmatics was determined by skin prick test (SPT). Lung functions were assessed by spirometry. Determination of ACE genotypes was performed for all subjects. Total serum IgE levels were measured by ELISA.

RESULTS

The frequencies of the DD, ID and II genotypes were 46.7%, 40%, and 13.3%, respectively among the cases, and 33.3%, 40%, and 26.7%, respectively among the controls. No significant differences in ACE genotype distribution were observed between cases and controls (p=0.37). Genotype distribution did not differ according to age of onset or severity of asthma, total serum IgE levels, SPT positivity, or number of positive SPT reactions. Furthermore, ACE polymorphism was not statistically different between asthmatic patients without any associated atopic disease and those with an associated atopic disease.

CONCLUSION

The results of our study indicate that ACE gene polymorphism is not significantly associated with bronchial asthma or with its severity among Egyptian adults.

Association between angiotensin-converting enzyme I/D polymorphism and asthma risk: a meta-analysis involving 11,897 subjects

BACKGROUND

Genetic susceptibility to asthma has been a research focus in the scientific community. Several studies have been conducted in recent years to evaluate the risk of asthma and insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE). However, the results remain conflicting rather than conclusive.

METHODS

We carried out a search in Medline, EMBASE, and Chinese National Knowledge Infrastructure (CNKI) database for relevant studies. Data were extracted using a standardized form and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the strength of the association.

RESULTS

Our meta-analysis on 11,897 subjects from all available studies showed that the DD genotype was associated with increased asthma risk than those with the II (OR = 1.59, 95% CI = 1.20-2.12) or ID/II (OR = 1.62, 95% CI = 1.24-2.10) genotype. Stratified analyses by ethnicity (Europeans and Asians) and age (adults and children) obtained statistically similar results in the two genetic models. In the subgroup analysis by source of controls, the DD genotype was associated with a significantly elevated risk of asthma among population-based controls (DD vs. II: OR = 2.27, 95% CI = 1.45-3.56) but not hospital-based controls (DD vs. II: OR = 1.18, 95% CI = 0.93-1.49).

CONCLUSIONS

This meta-analysis provides strong evidence that the I/D polymorphism of ACE is associated with asthma risk. Additional well-designed large studies were required for the validation of our results, especially in African populations.

The I/D polymorphism of angiotensin-converting enzyme gene and asthma risk: a meta-analysis

BACKGROUND

  The insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) gene has been implicated in susceptibility to asthma, but a large number of studies have reported inconclusive results. The aim of this study is to investigate the association between the I/D polymorphism of ACE gene and asthma risk by meta-analysis.

METHODS

  We searched Medline (Ovid), Pubmed, CNKI, Wanfang, and Weipu database, covering all papers until March 12, 2010. Statistical analysis was performed by using the software revman 4.2 (The Cochrane Collaboration, http://www.cochrane.org) and stata 10.0 (StataCorp, College Station, TX, USA, http://www.stata.com).

RESULTS

  A total of 1946 cases and 2152 controls in 18 case-control studies were included in this meta-analysis. The results indicated that the DD homozygote carriers had a 59% increased risk of asthma, when compared with the homozygotes II and heterozygote DI [odds ratio (OR)=1.59, 95% confidence interval (CI): 1.16-2.18]. In the subgroup analysis by ethnicity, significant elevated risks were associated with DD homozygote carriers in Asians (OR=2.02 and 95% CI: 1.29-3.16 for DD vs DI+II) but not in Caucasians (OR=1.14 and 95% CI: 0.76-1.72 for DD vs DI+II). In the subgroup analysis by age, significant elevated risks were associated with DD homozygote carriers in children (OR=2.44 and 95% CI: 1.36-4.38 for DD vs II+DI) but not in adults (OR=1.54 and 95% CI: 0.94-2.51 for DD vs II+DI).

CONCLUSIONS

  This meta-analysis suggested that the I/D polymorphism of ACE gene would be a risk factor of asthma. To further evaluate gene-to-gene and gene-to-environment interactions between polymorphisms of ACE gene and asthma risk, more studies with large groups of patients are required.