Angiotensin-converting enzyme gene insertion/deletion polymorphism and essential hypertension in the Chinese population: a meta-analysis including 21 058 participants

ACE gene polymorphism and susceptibility to hypertension in a Jordanian adult population

Hypertension is one of the most common and complicated disorders associated with genetic and environmental risk factors. The angiotensin-converting enzyme (ACE) is important in the renin-angiotensin-system pathway. The gene expression of ACE has been investigated as a possible hypertension marker. This study investigates the association between polymorphisms within the ACE1 and ACE2 genes and hypertension susceptibility in a Jordanian population. The study comprised a total of 200 hypertensive patients and 180 healthy controls. A polymerase chain reaction (PCR) was performed to genotype the candidate polymorphism (rs4646994) of the ACE1gene. The Luminex DNA array technique was used for genotyping SNPs (rs4359, rs4344, rs4341, rs4343, and rs2106809) of the ACE1 and ACE2 genes. Our findings suggest no association between SNPs and hypertension regarding allelic and genotypic frequencies. However, rs4359 was significantly associated with diet (pP = 0.049), know HTN (P = 0.042), and number of years DM (P = 0.003). rs4341 was associated with diet (P = 0.032), peripheral vascular disease (P = 0.005), and chronic kidney disease (p = 0.049). While rs4343 was associated with diet (P = 0.031), diabetes mellitus (P = 0.032), and other medication (P = 0.025). Furthermore, the haplotypes of four SNPs of the ACE1 gene showed no significant association with HTN patients and healthy controls. Our findings indicate no association between the polymorphisms in the ACE gene and the risk of hypertension development in the Jordanian adult population.

Mathematical modelling of the influence of ACE I/D polymorphism on blood pressure and antihypertensive therapy

The angiotensin-converting enzyme (ACE) gene (ACE) insertion/deletion (I/D) polymorphism raises the possibility of personalising ACE inhibitor therapy to optimise its efficiency and reduce side effects in genetically distinct subgroups. However, the extent of its influence among these subgroups is unknown. Therefore, we extended our computational model of blood pressure regulation to investigate the effect of the ACE I/D polymorphism on haemodynamic parameters in humans undergoing antihypertensive therapy. The model showed that the dependence of blood pressure on serum ACE activity is a function of saturation and therefore, the lack of association between ACE I/D and blood pressure levels may be due to high ACE activity in specific populations. Additionally, in an extended model simulating the effects of different classes of antihypertensive drugs, we explored the relationship between ACE I/D and the efficacy of inhibitors of the renin-angiotensin-aldosterone system. The model predicted that the response of cardiovascular and renal parameters to treatment directly depends on ACE activity. However, significant differences in parameter changes were observed only between groups with high and low ACE levels, while different ACE I/D genotypes within the same group had similar changes in absolute values. We conclude that a single genetic variant is responsible for only a small fraction of heredity in treatment success and its predictive value is limited.

Sex Differences in the Efficacy of Mediterranean Diet Treatment: A Nutrigenomics Pilot Study

The Mediterranean diet (MedD) has been shown to have beneficial effects on health, well-being, and mental status. It potentially modulates gene expressions linked to oxidative stress, contributing to its beneficial effects on overall health. The aim of this study was to assess the effects of MedD treatment in healthy human volunteers on the expression of ten genes related to oxidative stress and inflammation in women and men. Of 30 enrolled subjects, 17 were eligible, 10 women and 7 men. All of them received the same MedD treatment. Before and after 8 weeks of MedD treatment, an evaluation of body composition, blood tests, and anthropometric and clinical parameters was performed. Furthermore, 10 genes were amplified and analyzed. The study showed significant differences between females and males in body composition and biochemical parameters before and after MedD treatment. Significant differences between females and males in Resistance Force (p < 0.009) and Diastolic Blood Pressure (p < 0.04) before MedD treatment, and in High-Density Lipoprotein (p < 0.02) after MedD treatment, were observed. Moreover, a significant upregulation of Apolipoprotein E and Angiotensin I-Converting Enzyme in females has been shown. Sex differences impact MedD treatment response, and influence the genetic expression of genes related to oxidative stress; our findings may help to personalize diet therapy and contribute to overall health and well-being.

When blood pressure refuses to budge: exploring the complexity of resistant hypertension

Resistant hypertension, defined as blood pressure that remains above goal despite using three or more antihypertensive medications, including a diuretic, affects a significant proportion of the hypertensive population and is associated with increased cardiovascular morbidity and mortality. Despite the availability of a wide range of pharmacological therapies, achieving optimal blood pressure control in patients with resistant hypertension remains a significant challenge. However, recent advances in the field have identified several promising treatment options, including spironolactone, mineralocorticoid receptor antagonists, and renal denervation. In addition, personalized management approaches based on genetic and other biomarkers may offer new opportunities to tailor therapy and improve outcomes. This review aims to provide an overview of the current state of knowledge regarding managing resistant hypertension, including the epidemiology, pathophysiology, and clinical implications of the condition, as well as the latest developments in therapeutic strategies and future prospects.

Development of a genetic risk score to predict the risk of hypertension in European adolescents from the HELENA study

Introduction

From genome wide association study (GWAS) a large number of single nucleotide polymorphisms (SNPs) have previously been associated with blood pressure (BP) levels. A combination of SNPs, forming a genetic risk score (GRS) could be considered as a useful genetic tool to identify individuals at risk of developing hypertension from early stages in life. Therefore, the aim of our study was to build a GRS being able to predict the genetic predisposition to hypertension (HTN) in European adolescents.

Methods

Data were extracted from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) cross-sectional study. A total of 869 adolescents (53% female), aged 12.5-17.5, with complete genetic and BP information were included. The sample was divided into altered (≥130 mmHg for systolic and/or ≥80 mmHg for diastolic) or normal BP. Based on the literature, a total of 1.534 SNPs from 57 candidate genes related with BP were selected from the HELENA GWAS database.

Results

From 1,534 SNPs available, An initial screening of SNPs univariately associated with HTN (p < 0.10) was established, to finally obtain a number of 16 SNPs significantly associated with HTN (p < 0.05) in the multivariate model. The unweighted GRS (uGRS) and weighted GRS (wGRS) were estimated. To validate the GRSs, the area under the curve (AUC) was explored using ten-fold internal cross-validation for uGRS (0.802) and wGRS (0.777). Further covariates of interest were added to the analyses, obtaining a higher predictive ability (AUC values of uGRS: 0.879; wGRS: 0.881 for BMI z-score). Furthermore, the differences between AUCs obtained with and without the addition of covariates were statistically significant (p < 0.05).

Conclusions

Both GRSs, the uGRS and wGRS, could be useful to evaluate the predisposition to hypertension in European adolescents.

Polymorphisms in the Renin-Angiotensin System and eNOS Glu298Asp Genes Are Associated with Increased Risk for Essential Hypertension in a Mexican Population

Background

Essential hypertension is the result of modifiable and genetic factors, and it is associated with increased risk for atherothrombosis. Some polymorphisms are associated with hypertensive disease. The objective was to analyze the association between eNOS Glu298Asp, MTHR C677T, AGT M235T, AGT T174M, and A1166C and ACE I/D polymorphisms with essential hypertension in the Mexican population.

Materials and Methods

In the present study, 224 patients with essential hypertension and 208 subjects without hypertension were included. The Glu298Asp, C677T, M235T, T174M, A1166C, and I/D polymorphisms were determined by the PCR-RFLP technique.

Results

We found statistical differences in age, gender, BMI, systolic and diastolic blood pressure, and total cholesterol between control and cases. However, we found no significant differences in HbA1c and triglycerides between both groups. We observed statistical significant differences in the genotype distribution of Glu298Asp (P = 0.001), I/D (P = 0.02), and M235T (P = 0.004) polymorphisms between both groups. In contrast, there were no differences related to distribution of genotypes of MTHFR C677T (P = 0.12), M174T (P = 0.46), and A1166C (P = 0.85) between cases and control groups.

Conclusions

We identified that Glu298Asp, I/D, and M234T polymorphisms represented an increased risk for essential hypertension and those genetic variants could contribute to the presence of endothelial dysfunction and vasopressor effect, hyperplasia, and hypertrophy of smooth muscle cells, which had an impact for hypertension. In contrast, we found no association between C677C, M174T, and A1166C polymorphisms and hypertensive disease. We suggested that those genetic variants could be identified in individuals with high risk to avoid hypertension and thrombotic disease.

Artificial Intelligence-Assisted Meta-Analysis of the Frequency of ACE I/D Polymorphisms in Centenarians and Other Long-Lived Individuals

Current research on the angiotensin-converting-enzyme (ACE) gene has yielded controversial results on whether different ACE polymorphisms are linked with human longevity. ACE polymorphisms are a risk factor for Alzheimer's disease and age-onset diseases that may contribute to the mortality of older people. Our goal is to consolidate existing studies, using artificial intelligence-assisted software to come to a more precise understanding of the role of the ACE gene in human longevity. The I (insertion) and D (deletion) polymorphisms in the intron are correlated with the levels of circulating ACE; homozygous D (DD) is high, and homozygous I (II) is low. Here, we performed a detailed meta-analysis of the I and D polymorphisms using centenarians (100+ years old), long-lived subjects (85+ years old), and control groups. ACE genotype distribution was analyzed across a total of 2054 centenarians and 12,074 controls, as well as 1367 long-lived subjects between the ages of 85-99, using the inverse variance and random effects methods. The ACE DD genotype was found to be favored in centenarians (OR: 1.41 (95% CI: 1.19-1.67), p < 0.0001) with a heterogeneity of 32%, and the II genotype slightly favored the control groups (OR: 0.81 (95% CI: 0.66-0.98), p = 0.03) with a heterogeneity of 28%, corroborating results from previous meta-analyses. Novel to our meta-analysis, the ID genotype was found to be favored in control groups (OR: 0.86 (95% CI: 0.76-0.97), p = 0.01) with a heterogeneity of 0%. The long-lived group showed a similar positive association between the DD genotype and longevity (OR: 1.34 (95% CI: 1.21-1.48), p < 0.0001) and a negative association between the II genotype and longevity (OR: 0.79 (95% CI: 0.70-0.88), p < 0.0001). The long-lived ID genotype did not show significant findings (OR: 0.93 (95% CI: 0.84-1.02), p = 0.79). In conclusion, the results suggest a significant positive association of the DD genotype with human longevity. However, despite the previous study, the results do not confirm a positive association of the ID genotype with human longevity. We suggest a few important paradoxical implications: (1) inhibition of ACE can increase longevity in model systems from nematodes to mammals, seemingly opposite to the finding in humans; (2) exceptional longevity associated with homozygous DD is also associated with age-related diseases with higher mortality risks in homozygous DD. We discuss ACE, longevity, and age-related diseases.

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.

Co-exposure to urban particulate matter and aircraft noise adversely impacts the cerebro-pulmonary-cardiovascular axis in mice

Worldwide, up to 8.8 million excess deaths/year have been attributed to air pollution, mainly due to the exposure to fine particulate matter (PM). Traffic-related noise is an additional contributor to global mortality and morbidity. Both health risk factors substantially contribute to cardiovascular, metabolic and neuropsychiatric sequelae. Studies on the combined exposure are rare and urgently needed because of frequent co-occurrence of both risk factors in urban and industrial settings. To study the synergistic effects of PM and noise, we used an exposure system equipped with aerosol generator and loud-speakers, where C57BL/6 mice were acutely exposed for 3d to either ambient PM (NIST particles) and/or noise (aircraft landing and take-off events). The combination of both stressors caused endothelial dysfunction, increased blood pressure, oxidative stress and inflammation. An additive impairment of endothelial function was observed in isolated aortic rings and even more pronounced in cerebral and retinal arterioles. The increase in oxidative stress and inflammation markers together with RNA sequencing data indicate that noise particularly affects the brain and PM the lungs. The combination of both stressors has additive adverse effects on the cardiovascular system that are based on PM-induced systemic inflammation and noise-triggered stress hormone signaling. We demonstrate an additive upregulation of ACE-2 in the lung, suggesting that there may be an increased vulnerability to COVID-19 infection. The data warrant further mechanistic studies to characterize the propagation of primary target tissue damage (lung, brain) to remote organs such as aorta and heart by combined noise and PM exposure.

Analysis of the Pattern, Alliance and Risk of rs1799752 (ACE I/D Polymorphism) with Essential Hypertension

Studies in spontaneously hypertensive rat had revealed an elevated level of ACE gene expression in the tissues and is substantiated by experimental clinical studies for a positive correlation between ACE I/D polymorphism and hypertension. Aim: To determine whether the polymorphic variant of ACE gene in intron 16 confers susceptibility to essential hypertension. I/D polymorphism at the locus intron 16 of the ACE gene were amplified from the genomic DNA of the total 571 (hypertensive patients, n: 279; controls, n: 292) participants using polymerase chain reaction and gel electrophoresis methods and were examined in a case-control approach. Suitable descriptive statistics was used for different variables. Result revealed significant heterogeneity under the allele (p: 0.0002) and genotype (p: 0.0001) contrast in hypertensive patients than in normal controls, with an increased frequency of D allele (62.72%; p < 0.0001; OR: 1.8144; 95% CI: 1.4327-2.2979) and DD genotype (41.93%; p: < 0.0001). A significant association was found in the DD variant with disease phenotype (p: 0.0018, 95% CI: 1.3303-3.4907; OR: 2.1549; Table 31) and is substantiated by the data of multivariate analysis, demonstrating a statistically significant increase in odds of hypertension with the ACE D/D genotype (OR: 2.09; 95% CI: 1.24-2.91). Conspicuously, subgroup analysis by gender did not change this pattern of results. Albeit the allele distribution resulted in a higher frequency of the D/D genotype in the cases than controls, testing genetic equilibrium between the observed and expected genotypes using Hardy-Weinberg equilibrium showed ACE gene variants were confirming to the law in hypertensive as well as in non-hypertensive participants. I/D polymorphism in the angiotensin-I-converting enzyme gene at the 16th intron can be useful for outcome predictions during diagnostic processes can be implicated in an individual's propensity for hypertension and thus implies that genetic variants of ACE I/D might serve as a predictor for the susceptibility to hypertension.

Insertion/deletion polymorphism at angiotensin-converting enzyme gene in PTSD individuals and their reciprocal effects on blood pressure

OBJECTIVES

The aim of the present study was to investigate relationships between insertion/deletion (I/D) polymorphism at angiotensin-converting enzyme gene (ACE) and post-traumatic stress disorder (PTSD), as well as their interactions on blood pressure.

METHODS

Variants of ACE I/D were identified by polymerase chain reaction method and verified by DNA sequencing. PTSD symptoms were assessed by the PTSD Checklist-Civilian Version (PCL-C) based on DSM-IV-TR criteria among high school students at 6 months after the 2008 Wenchuan earthquake.

RESULTS

Female subjects were found to have higher prevalence of PTSD and PCL-C scores than male counterparts in the II homozygotes (p = .038 for PTSD and p = .003 for PCL-C scores) and the ID heterozygotes (p = .000 for PTSD and p = .000 for PCL-C scores), but not in the DD homozygotes. Male subjects with the ID (p = .046) or the DD genotype (p = .039) had lower pulse pressure (PP) than the male II homozygotes, while the female II homozygotes had lower diastolic blood pressure (DBP) than the female DD homozygotes (p = .036). ACE I/D, PTSD, or PCL-C scores, as well as gender and BMI, were found to be the predictors of PP.

CONCLUSIONS

These results indicate that there are interactions of ACE I/D and PTSD, together with gender and BMI, on PP. This finding may be the additional explanation for the heterogeneous relationships between PTSD and blood pressure, and suggest psychiatry care and different medication strategies for patients with comorbidities of PTSD and hypertension and with different genotypes of ACE I/D.

The Renin-Angiotensin-Aldosterone System and Coronavirus Disease 2019

The renin-aldosterone-angiotensin system (RAAS) plays an important role in the pathogenesis of coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for SARS-CoV-2 and the host's expression of this membrane-bound protein could affect susceptibility to infection. The RAAS is an important regulator of cardiovascular physiology and ACE2 has an essential role. People with hypertension and other traits have shown to have an imbalance in ACE/ACE2 levels and reduced levels of ACE2 could enhance the risk of adverse outcome in patients with COVID-19. It has been hypothesised that the RAAS may mediate the interplay between cardiovascular disease and COVID-19 severity. Evidence shows that antihypertensive drugs that target the RAAS have no significant effect on the risk of infection and disease outcome. Variations in RAAS genes have been associated with the risk of developing hypertension and cardiovascular disease and could partly explain the heterogenous response to SARS-CoV-2 infection. This article explores the interplay between the RAAS and COVID-19, with emphasis on the possible relationship between genetic variations and disease severity.

Mutation differences in circulating tumor DNAs from non-small cell lung cancer patients between Uygur and Han populations

BACKGROUND

The incidence of non-small cell lung cancer (NSCLC) in Uygur population is gradually increasing recently. In view of the great diagnostic and prognostic values of cell-free DNAs (cfDNA) detection, this study focus on a liquid biopsy to explore the value of cfDNA mutation in healthy and NSCLC patients in 2 ethnicities.

METHODS

The concentration and sequencing of cfDNA in NSCLC and healthy subjects was assessed with a standard information analysis procedure, including detection, annotation, and statistical analysis. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were conducted to analyze the function of mutant genes and related pathways. Totally, 133 subjects, including 35 Uygur NSCLC patients, 10 Uygur healthy subjects, 63 cases of Han NSCLC patients and 25 Han health control, were admitted to the hospital.

RESULTS

There were a lower proportion of adenocarcinoma and higher percentage of smoking rate for Uygur patients. For cfDNA level between NSCLC and healthy subjects, Han patients exhibited sharp increase while there was no statistical difference in Uygur population. In addition, the mutation frequency of cfDNA in Han patients (72.6%) was significantly higher than Uygur patients (45.7%). There were 5 gene mutations only found in Han patients and ABCC11 showed a higher mutation frequency in Uygur population as a common one. Finally, Go and Kyoto Encyclopedia of Genes and Genomes analysis showed apprent functional enrichments and pathway changes between 2 ethnicities.

CONCLUSION

There existed distinct distributions of cancer subtypes, smoking proportion, cfDNA level, and mutation patterns between Han and Uygur patients. The results may be a useful tool in NSCLC patients' diagnosis as well as individualized therapy between ethnicities in future.

The D allele of angiotensin-converting enzyme gene is associated with a worse autonomic heart control in community-based older adults

The relationship between the Renin-Angiotensin-Aldosterone System (RAAS) and modulation of the Autonomic Nervous System (ANS) is reported as complex and bidirectional. Thus, the present study aimed to compare autonomous heart control, through symbolic analysis parameters, in the older adults carrying different ACE I/D gene polymorphisms (rs4646994). Two hundred four older adults comprised the study population and were grouped according to the ACE I/D gene polymorphism: II + ID genotype and DD genotype. Successive RR intervals were recorded along 5 min and analyzed with Symbolic Analysis (SA) method. 0 V%, 1 V% and 2 V% patterns were quantified and compared between groups. A linear mixed model analysis was used to determine between-group differences in symbolic analysis parameters (0 V%, 1 V% and 2 V%), taken groups as fixed factor and sex, use of ACE inhibitors and Angiotensin II receptor type I blockers as random factors. The Bayesian analysis was carried out to check the magnitude of the evidence. The results of this study indicate that older adults carrying the DD genotype have statistically greater sympathetic modulation (0 V%) and poor sympathovagal balance (1 V%), but the Bayesian analysis indicate only an anecdotal effect. Sympathetic predominance is recognized a worrying condition, since may predisposes to cardiovascular risk.

Diet-gene interaction: effects of polymorphisms in the ACE, AGT and BDKRB2 genes and the consumption of sodium, potassium, calcium, and magnesium on blood pressure of normotensive adult individuals

Functional variants in genes of the renin-angiotensin (RAS) and kallikrein-kinin (KKS) systems have already been implicated in blood pressure (BP) modulation, but few studies have focused on a nutrigenetics approach. Thus, the aim of this study is to verify the effects of the interaction between genetic polymorphisms (rs4340-ACE, rs699-AGT, and rs1799722-BDKRB2) and micronutrient consumption (sodium, potassium, calcium, and magnesium) on BP values of normotensive adult individuals. The study included 335 adults, men and women, 25.5 (6.6) years old. Biochemical, anthropometric, BP measurements, and food intake data were assessed for all participants. Gene-nutrient interaction on BP outcome was tested by multiple linear regression with manual backward stepwise modeling. Our results indicated that individuals with G allele for rs699 polymorphism, in the increase of sodium and magnesium consumption, both in the genotypic model (sodium, p = 0.035; magnesium, p = 0.016) and in the dominant model (sodium, p = 0.009; magnesium, p = 0.006) had higher systolic BP (SBP) levels compared to AA homozygotes (sodium, p = 0.001; magnesium, p < 0.001). Also, individuals with the T allele for the rs1799722 polymorphism, with higher calcium intake, had significantly higher levels of SBP and diastolic BP (DBP) when compared to CC homozygotes (p = 0.037). In conclusion, our findings pointed for significant interactions between genetic polymorphisms (rs699-AGT and rs1799722-BDKRB2) and the consumption of micronutrients (sodium, magnesium, and calcium) on the BP variation. These findings contribute to the understanding of the complex mechanisms involved in BP regulation, which probable include several gene-nutrition interactions.

The combination of ACE I/D and ACE2 G8790A polymorphisms revels susceptibility to hypertension: A genetic association study in Brazilian patients

BACKGROUND

Systemic arterial hypertension (SAH) is a multifactorial condition that already affects one third of the worldwide population. The identification of candidate genes for hypertension is a challenge for the next years. Nevertheless, the small contribution of each individual genetic factor to the disease brings the necessity of evaluate genes in an integrative manner and taking into consideration the physiological interaction of functions. Angiotensin I-converting enzymes, ACE and ACE2, are key regulators of blood pressure that have counterbalance roles by acting on vasoactive peptides from Renin-Angiotensin-Aldosterone System (RAAS). Insertion/deletion (I/D) polymorphism of ACE gene and single nucleotide polymorphism G8790A of ACE2 gene have been associated with susceptibility to SAH, but the literature is controversial. We proposed to evaluate these two polymorphisms jointly exploring the combined effects of ACE and ACE2 genotypes on SAH susceptibility, an approach that have not been done yet for ACE and ACE2 polymorphisms.

METHODS AND FINDINGS

This genetic association study included 117 hypertensive (mean age 59.7 years) patients and 123 normotensive and diabetes-free controls (mean age 57.5 years). ACE and ACE2 polymorphisms were genotyped by SYBR Green real-time PCR and RFLP-PCR, respectively. Crude and adjusted odds ratio (OR) values were calculated to estimate the susceptibility to SAH development. It was obtained homogeneity regarding distribution by sex, age range, smoking, alcohol consumption and body mass index (BMI) between case and control groups. No-association was verified for each gene individually, but the combination of ACE and ACE2 polymorphisms on female gender revealed a significative association for DD/G_ carriers who had a 3-fold increased risk to SAH development (p = 0.03), with a stronger susceptibility on DD/GG carriers (7-fold increased risk, p = 0.01). The D allele of ACE showed association with altered levels of lipid profile variables on case group (VLDL-cholesterol, p = 0.01) and DD genotype in all individuals analysis (triglycerides, p = 0.01 and VLDL-cholesterol, p = 0.01).

CONCLUSION

These findings indicate that the combination of ACE and ACE2 polymorphisms effects may play a role in SAH predisposition been the DD/G_ genotype the susceptibility profile. This result allowed us to raise the hypothesis that an increased activity of ACE (prohypertensive effects) in conjunction with reduced ACE2 activity (antihypertensive effects) could be the underlining mechanism. The association of ACE D allele with lipid alterations indicate that this can be a marker of poor prognostic on SAH evolution and contribute to CVD development. Although these preliminary findings must be confirmed by further researches with larger sample size, we could observe that the integrative analysis of ACE and ACE2 can be an informative tool in hypertension understanding that needs to be explored in new studies.

Effects of angiotensin converting enzyme gene polymorphism on hypertension in Africa: A meta-analysis and systematic review

BACKGROUND

Hypertension is dramatically increasing in Africa with evidence of increased severity and resistance to treatment. Although angiotensin converting enzyme gene polymorphism is associated with higher prevalence of hypertension, the evidence is inconclusive on its influence on the emerging pattern in Africa. This meta-analysis is conducted to pool the available evidence to inform future research and interventions.

METHODS

Articles published through May 2018 were systematically searched in PubMed, Scopus and EMBASE databases. Studies were assessed for inclusion by two independent researchers. Six models were used to assess the effect of angiotensin converting enzyme deletion-insertion gene polymorphism. Heterogeneity and publication bias were tested and sensitivity analysis was carried out. Odds ratio and 95% confidence intervals were measured for pooled effect. Both random effect and fixed effect models were used, whilst the frequency of DD, II and DI genotypes were computed and compared.

RESULT

Patients with D allele were 1.49 times more likely to develop essential hypertension compared with patients who carry the I allele (OR:1.49; CI:1.07, 2.07). Similarly, patients who had homozygous co-dominance genotype DD (i.e., DD vs II) were at a 2.17 times higher risk of essential hypertension compared to the co-dominant genotype II (OR:2.17, CI:1.79, 3.18), dominant model (I.e., DD+ID vs II) (OR:1.48; CI:1.03, 2.12), and recessive model (OR:1.64; CI:1.03, 2.61). On subgroup analysis, participants from Sub-Saharan Africa were more genetically susceptible to hypertension compared to their North Africa counterparts. There was no publication bias found, but there was high to moderate heterogeneity.

CONCLUSION

ACE I/D polymorphism is associated with essential hypertension in Africa in the allele contrast model, as well as the dominant, recessive and homozygous codominance model. On subgroup analysis, ACE I/D was associated with essential hypertension in patients from Sub-Saharan Africa but not in North Africa. A future large scale study, which includes different ethnic groups, is recommended.

ADRB3 Gene Trp64Arg Polymorphism and Essential Hypertension: A Meta-Analysis Including 9,555 Subjects

Background: Presence of the β3-Adrenergic receptor (ADRB3) gene Trp64Arg (T64A) polymorphism may be associated with an increased susceptibility for essential hypertension (EH). A clear consensus, however, has yet to be reached.

Objective and methods: To further elucidate the relationship between the ADRB3 gene Trp64Arg polymorphism and EH, a meta-analysis of 9,555 subjects aggregated from 16 individual studies was performed. The combined odds ratios (ORs) and their corresponding 95% confidence intervals (CI) were evaluated using either a random or fixed effect model.

Results: We found a marginally significant association between ADRB3 gene Trp64Arg polymorphism and EH in the whole population under the additive genetic model (OR: 1.200, 95% CI: 1.00–1.43, P = 0.049). Association within the Chinese subgroup, however, was significant under allelic (OR: 1.150, 95% CI: 1.002–1.320, P = 0.046), dominant (OR: 1.213, 95% CI: 1.005–1.464, P = 0.044), heterozygous (OR: 1.430, 95% CI:1.040–1.970, P = 0.03), and additive genetic models (OR: 1.280, 95% CI: 1.030–1.580, P = 0.02). A significant association was also found in the Caucasian subgroup under allelic (OR: 1.850, 95% CI: 1. 260–2.720, P = 0.002), dominant (OR: 2.004, 95% CI: 1.316–3.052, P = 0.001), heterozygous (OR: 2.220, 95% CI: 1.450–3.400, P = 0.0002), and additive genetic models (OR: 2.000, 95% CI: 1. 330–3.010, P = 0.0009).

Conclusions: The presence of the ADRB3 gene Trp64Arg polymorphism is positively associated with EH, especially in the Chinese and Caucasian population. The Arg allele carriers of ADRB3 gene Trp64Arg polymorphism may be at an increased risk for developing EH.

Daily sodium intake influences the relationship between angiotensin-converting enzyme gene insertion/deletion polymorphism and hypertension in older adults

The angiotensin-converting enzyme insertion/deletion (I/D) gene polymorphism has been widely reported as being associated with hypertension; however, most studies do not consider environmental/behavioral factors. This study aimed to investigate the relationship among angiotensin-converting enzyme insertion/deletion gene polymorphism, environmental/behavioral factors, and hypertension in community-dwelling elderly individuals. All community-dwelling older adults from Aiquara, Bahia, Brazil, were invited to take part in this study. After exclusions, 234 elderly participants were submitted to a data collection, which included sociodemographics, lifestyle and health status questionnaires, clinical assessment, and blood withdrawal. From the blood samples, the gene polymorphism was identified through polymerase chain reaction and patients grouped as II or D allele carriers (ID and DD genotypes). Hypertension was defined by self-report of the condition and confirmed by antihypertensive drug treatment. Chi-square test was used to identify differences in the proportions distributed between groups of each dependent variable (ie, genotype, diagnosis of hypertension, and blood pressure state from medicated patients with hypertension). The prevalence of hypertension was 59.3% and was associated with diabetes mellitus and obesity, but not with angiotensin-converting enzyme insertion/deletion gene polymorphism. However, carriers of the II genotype, a salt-sensitivity genotype, exhibited a significantly greater estimated sodium intake. In addition, among medicated elderly patients with hypertension, II genotype carriers exhibited poor blood pressure control, despite similar antihypertensive drug treatment in D allele carriers, while exhibiting a greater estimated sodium intake. Our results provide new evidence regarding the interaction of genetic and environmental/behavioral factors in the genesis of hypertension among elderly patients, as well as in blood pressure control in medicated elderly patients with hypertension.

Association of ACE gene A2350G and I/D polymorphisms with essential hypertension in the northernmost province of China

Angiotensin converting enzyme (ACE) gene, as a strong candidate gene for essential hypertension(EH), has been extensively studied. In this study, we carried out a population-based case-control study to explore whether ACE gene I/D and A2350G polymorphisms could consider to be risk factors for EH. A total of 2040 subjeces were recruited from Chinese Han in this study, out of which 1010 were cases and 1030 were normotensive individuals. ACE gene A2350G and I/D polymorphisms were amplified by polymerase chain reaction (PCR) and A2350G polymorphism was detected after restriction enzyme digestion with BstuI. Besides, we choosed 10% samples randomly sequencing to verify the accuracy of results. Genotype and allele frequencies distribution of I/D and A2350G in EH and control groups were significantly different. After grouped by sex or age, there were still statistical significances for two polymorphisms. In dominant and recessive model of A2350G, we found significant differences between two groups, respectively. For ACE I/D polymorphism, we observed that the existence of dramatical difference in dominant model between two groups, while in recessive model, marginally significant difference was found. Among the four haplotypes composed by ACE gene A2350G and I/D, haplotype G-D reached the statistical significance in two groups, and exhibited to be a risk factor for the development of EH, whose P < 0.001 and OR 95%CI = 1.639(1.435-1.872), while the other haplotypes were the protective factors and decreased the susceptibility to EH(P < 0.05). ACE gene A2350G and I/D polymorphisms were associated with increasing the risk of suffering from EH in the northernmost province of China individuals, with D allele and G allele individuals had a higher risk of EH(OR = 1.443, 95%CI = 1.273-1.636 and OR = 1.481, 95%CI = 1.303-1.684).

A case control association study of ACE gene polymorphism (I/D) with hypertension in Punjabi population from Faisalabad, Pakistan

Angiotensin converting enzyme (ACE) is a key component of renin angiotensin aldosterone system. It converts angiotensin I to angiotensin II. Insertion/deletion (I/D) polymorphism of ACE gene is found associated with several complications. However, its association with hypertension and related metabolic diseases is still controversial. So, the aim of the present study was to check this association for Punjabi population from Faisalabad, Pakistan. For this purpose, blood samples (patients = 100, controls = 48) were collected and several biochemical parameters were measured. Genotyping for ACE (I/D) polymorphism was performed by polymerase chain reaction (PCR) assay. ID genotype is found prevalent in the studied population as 41% in control subjects and 61% in patients. Furthermore, chi-square analysis showed significant (p = 0.005) difference for genotypic frequencies between both groups. One-way ANOVA for association of II, ID, and DD genotypes with anthropometric, clinical, and biochemical parameters showed that in patient group, DD genotype is significantly (p = 0.041) associated with systolic blood pressure (SBP). Moreover, ID genotype is found associated with the presence of cardiovascular diseases. This study concludes that DD genotype is strongly associated with higher SBP in hypertensive patients.

Use of Genetic Algorithm Combinational Single-nucleotide Polymorphisms Could Modify the Association of Blood Lead Levels and Bone Matrix Density

BACKGROUND

Previous studies have not explored the relationship between a single gene and a single disease. Our study aims to investigate the association of multiple genotypes with blood lead levels and bone matrix density (BMD) by using genetic algorithms.

METHODS

Our research focused on 506 employees (245 males and 261 females) of a lead battery factory in Taiwan. We collected data on their BMD, blood lead level, and 6 SNPs (ACE, alpha-adducin, Bsm, Tag, Apa, and ALAD); these factors were analyzed using discrete binary particle swarm optimization (DBPSO) and logistic regression analysis.

RESULTS

We found no association between blood lead level and bone density, which may be due to the relatively young age of this population (mean age = 45.1 years). However, the genotype that contained both Bsm type bb and ALAD type 1-1 may play an important role in protecting against lower bone density among these employees.

CONCLUSIONS

In conclusion, this study found that the Bsm and ALAD genes influence bone density among lead workers. However, the mechanism and exact relationship between these two genes and bone density require further investigation.

The association of insertions/deletions (INDELs) and variable number tandem repeats (VNTRs) with obesity and its related traits and complications

BACKGROUND

Despite the fact that insertions/deletions (INDELs) are the second most common type of genetic variations and variable number tandem repeats (VNTRs) represent a large portion of the human genome, they have received far less attention than single nucleotide polymorphisms (SNPs) and larger forms of structural variation like copy number variations (CNVs), especially in genome-wide association studies (GWAS) of complex diseases like polygenic obesity. This is exemplified by the vast amount of review papers on the role of SNPs and CNVs in obesity, its related traits (like anthropometric measurements, biochemical variables, and eating behavior), and its related complications (like hypertension, hypertriglyceridemia, hypercholesterolemia, and insulin resistance-collectively known as metabolic syndrome). Hence, this paper reviews the types of INDELs and VNTRs that have been studied for association with obesity and its related traits and complications. These INDELs and VNTRs could be found in the obesity loci or genes from the earliest GWAS and candidate gene association studies, like FTO, genes in the leptin-proopiomelanocortin pathway, and UCP2/3. Given the important role of the brain serotonergic and dopaminergic reward system in obesity susceptibility, the association of INDELs and VNTRs in these neurotransmitters' metabolism and transport genes with obesity is also reviewed. Next, the role of INS VNTR in obesity and its related traits is questionable, since recent large-scale studies failed to replicate the earlier positive associations. As obesity results in chronic low-grade inflammation of the adipose tissue, the proinflammatory cytokine gene IL1RA and anti-inflammatory cytokine gene IL4 have VNTRs that are implicated in obesity. A systemic proinflammatory state in combination with activation of the renin-angiotensin system and decreased nitric oxide bioavailability as found in obesity leads to endothelial dysfunction. This explains why VNTR and INDEL in eNOS and ACE, respectively, could be predisposing factors of obesity. Finally, two novel genes, DOCK5 and PER3, which are involved in the regulation of the Akt/MAPK pathway and circadian rhythm, respectively, have VNTRs and INDEL that might be associated with obesity.

SHORT CONCLUSION

In conclusion, INDELs and VNTRs could have important functional consequences in the pathophysiology of obesity, and research on them should be continued to facilitate obesity prediction, prevention, and treatment.

Single nucleotide polymorphism of adiponectin +276 G/T is associated with the susceptibility to essential hypertension in a Turkish population

BACKGROUND

It is well known that arterial stiffness is associated with hypertension. Recent studies have shown that adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, and eNOS E298D polymorphisms are likely to be risk factors for arterial stiffness. In this study, we aimed to investigate possible associations between these single-nucleotide polymorphisms (SNPs) and essential hypertension in a Turkish population.

METHODS

The study population consisted of 170 patients who were diagnosed with essential hypertension and 170 sex- and age-matched controls. Genotyping of adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, and eNOS E298D SNPs were performed using real-time polymerase chain reaction and commercially produced kits.

RESULTS

The percentage of the adiponectin +276 T allele carriers was significantly higher in the patients with hypertension (33%) than in the controls (25%, p < 0.011). Through multiple logistic regression analysis, the adiponectin +276 T allele carrier was found to be associated with an increased risk of hypertension (TT vs. GG and TG: odds ratio = 3.318, p = 0.014, 95% confidence interval: 1.269-8.678). The genotype distributions or allelic frequencies of ACE I/D, AGTR1 A1166C, and eNOS E298D SNPs did not significantly differ between the patients with hypertension and the controls.

CONCLUSION

The present study demonstrated that the adiponectin +276 G/T SNP is likely to be a risk factor for essential hypertension in a Turkish population.

GENETIC ASSOCIATION BETWEEN ARTERIAL STIFFNESS-RELATED GENE POLYMORPHISMS IN BRVO AND CRVO PATIENTS IN A TURKISH POPULATION

PURPOSE

To investigate possible associations between five different single-nucleotide polymorphisms, from genes associated with arterial stiffness and branch retinal vein occlusion (BRVO), or central retinal vein occlusion.

METHODS

A total of 187 patients with retinal vein occlusion (133 with BRVO and 54 with central retinal vein occlusion), and 167 controls, were enrolled in this study. All subjects were screened for hypertension, diabetes, smoking status, body mass index, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, total cholesterol, and very low-density lipoprotein. The genotyping of adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, eNOS E298D, and p22phox -242 C/T polymorphisms was performed using real-time polymerase chain reaction.

RESULTS

The percentage of the adiponectin +275 T allele carriers was significantly higher in the BRVO patients (37%) than in the controls (23%, P < 0.001). Similarly, the percentage of AGTR1 1166 C allele carriers was significantly higher in the BRVO patients (38%) than in the controls (24%, P < 0.001). At the multiple logistic regression analysis, the adiponectin +275 T allele carrier and AGTR1 1166 C allele carrier status were found to be associated with an increased risk of BRVO (TT vs. GG and TG: odds ratio = 2.278, P = 0.002, 95% confidence interval: 1.370-3.789; CC vs. AA and AC: odds ratio = 1.804, P = 0.025, 95% confidence interval: 1.079-3.017). The genotype distributions or allelic frequencies of ACE I/D, eNOS E298D, and p22phox -242 C/T did not significantly differ between the patients with BRVO and the control subjects. There was no significant difference between the central retinal vein occlusion patients and controls for the genotype or the allele frequency distributions of all evaluated single-nucleotide polymorphisms.

CONCLUSION

Adiponectin +276 G/T and AGTR1 A1166C single-nucleotide polymorphism are likely to be risk factors for BRVO.

Evaluation of Association of ADRA2A rs553668 and ACE I/D Gene Polymorphisms with Obesity Traits in the Setapak Population, Malaysia

BACKGROUND

α-adrenergic receptor 2A (ADRA2A) and angiotensin-converting enzyme (ACE) genes have been variably associated with obesity and its related phenotypes in different populations worldwide.

OBJECTIVES

This cross-sectional study aims to investigate the association of adrenergic receptor α2A (ADRA2A) rs553668 and angiotensin-converting enzyme (ACE) I/D single nucleotide polymorphisms (SNPs) with obesity traits (body mass index-BMI; waist-hip ratio-WHR; total body fat percentage - TBF) in a Malaysian population.

MATERIALS AND METHODS

Demographic and clinical variables were initially collected from 230 subjects via convenience sampling among residents and workers in Setapak, Malaysia, but in the end only 214 multi-ethnic Malaysians (99 males; 45 Malays, 116 ethnic Chinese, and 53 ethnic Indians) were available for statistical analysis. Genotyping was performed by polymerase chain reaction using DNA extracted from mouthwash samples.

RESULTS

The overall minor allele frequencies (MAFs) for ADRA2A rs553668 and ACE I/D were 0.55 and 0.56, respectively. Allele distribution of ACE I/D was significantly associated with ethnicity and WHR class. Logistic regression analysis showed that subjects with the ACE II genotype and I allele were, respectively, 2.15 and 1.55 times more likely to be centrally obese, but when adjusted for age and ethnicity, this association was abolished. Covariate analysis controlling for age, gender, and ethnicity also showed similar results, where subjects carrying the II genotype or I allele did not have significantly higher WHR. Combinatory genotype and allele analysis for ADRA2A rs553668 and ACE I/D showed that subjects with both ADRA2A rs553668 GG and ACE I/D II genotypes had significant lowest WHR compared to other genotype combinations.

CONCLUSIONS

The ACE II genotype might be a protective factor against central adiposity risk among the Malaysian population when in combination with the ADRA2A rs553668 GG genotype.

Angiotensinogen (AGT) M235T, AGT T174M and Angiotensin-1-Converting Enzyme (ACE) I/D Gene Polymorphisms in Essential Hypertension: Effects on Ramipril Efficacy

Background:

Hypertension, one of the most important risk factors for premature cardiovascular disease, is a major worldwide public health problem. Angiotensin-1-converting enzyme (ACE) and angiotensinogen (AGT) gene polymorphisms are thought to be associated with primary hypertension. In the present study, we examined the frequency of these gene polymorphisms in an adult population with and without essential hypertension. Furthermore, we evaluated the effect of ACE and AGT gene polymorphisms on ramipril treatment efficacy in the hypertensive patients.

Methods:

A total of 166 adults (83 hypertensives and 83 normotensives) were involved in the study and genotyped for AGTM235T (rs699), AGTT174M (rs4762) and ACEI/D (rs1799752) gene polymorphisms.

Results:

The genotype and allele distribution of the AGTM235T variant significantly differed between hypertensives and normotensives [odds ratio (OR) = 1.57% (T vs M allele), 95% confidence intervals (CIs): 1.01 - 2.44; p=0.045 for hypertensives]. However, none of the 3 studied Simple Nucleotide Polymorphisms were associated with the blood pressure-lowering response to ramipril.

Conclusion:

These results suggest that AGTM235T gene polymorphism is associated with essential hypertension. However, none of the AGTM235T, AGTT174M and ACEI/D gene polymorphisms influenced ramipril effectiveness.

Synergistic effects of gene polymorphisms of the renin-angiotensin-aldosterone system on essential hypertension in Kazakhs in Xinjiang

OBJECTIVE

To assess the synergistic effects of gene polymorphisms of the renin-angiotensin-aldosterone system (RAAS) on essential hypertension (EH) in Kazakhs in Xinjiang.

METHODS

A cross-sectional case-control association study was conducted in 52 1 hypertensive and 623 normotensive subjects of Kazakh ethnicity on eight common single nucleotide polymorphisms (SNPs) interspersed over five genes of the RAAS. SNPs were genotyped by polymerase chain reaction-restriction fragment length polymorphism. Interactions among the SNPs were analyzed by the multifactor dimensionality reduction method (MDR).

RESULTS

In single-locus analysis, subjects with AGT -6G, ACE D, and CYP11B2 -344C had increased susceptibility to EH (OR: 1.249; 1.425; 1.201). When subgrouped by sex, males with the t allele of REN Taq I had decreased risk for EH (OR: 0.529), and those with AGT -6G and CYP11B2 -344 C had increased risk for EH (OR: 1.498; 1.449). In females, carrying ACE D increased the risk for EH. (OR: 1.327). In six AGT haplotypes, H1 was protective, while H3 increased susceptibility to EH (OR: 0.683; 2.025). Interaction analysis by MDR showed that there was a strong synergistic effect between ACE I/D and CY11B2 (T-344C) and a moderate interaction between both ACE I/D and CY11B2 T-344C and AGT A-6G.

CONCLUSIONS

There was a strong synergistic effect between ACE I/D and CY11B2 T-344C and a moderate effect between both ACE I/D and CY11B2 T-344C and AGT A-6G. AGT -6G, ACE D, and CY11B2 -344C increased susceptibility to EH. REN Taq I, AGT -6G, CY11B2 -344 C and ACE D were associated with male and female EH, respectively. H1 and H3 of AGT were protective and risk haplotypes, respectively.

Angiotensin-converting enzyme gene polymorphisms and hypertension in occupational noise exposure in Egypt

BACKGROUND

The gene-environment interaction in the pathogenesis of hypertension has not been extensively studied in occupational noise.

OBJECTIVES

The aim of this study was to determine the relationship between noise and hypertension in Egyptian workers, the interaction of angiotensin-converting enzyme (ACE) gene polymorphisms as modifiers, and the possible relationship between noise hearing impairment and hypertension.

METHODS

Study subjects were divided into two groups depending on noise exposure level. The control group (n = 161) was exposed to noise intensity <85 dB and the exposed group (n = 217) was exposed to noise intensity ≧85 dB. A polymerase chain reaction was used to differentiate the various genotypes of ACE insertion/deletion (I/D) and ACE G2350A.

RESULTS

Noise significantly increased the likelihood of hypertension. Carriers of the genotypes AG, GG, and DD were vulnerable to hypertension on noise exposure. No association between hypertension and hearing impairment or noise-induced hearing loss (NIHL) was found.

CONCLUSION

Our results support the association between ACE gene polymorphisms and occurrence of hypertension in noise-exposed workers.

Relationship between angiotensin I-converting enzyme insertion/deletion gene polymorphism and retinal vein occlusion

To evaluate the association between angiotensin I-converting enzyme insertion/deletion (ACE I/D) gene polymorphism and retinal vein occlusion (RVO). A total of 80 patients with retinal vein occlusion who was admitted to the Eye Department of Kartal Training and Research Hospital between 2008 and 2011, and 80 subjects were enrolled in this retrospective case–control study. Patients who experienced RVO within one week to six months of study enrolment were included, and those with coronary artery diseases, prior myocardial infarction history and coagulation disturbances were excluded from the study. The diagnosis was made by ophthalmoscopic fundus examination and fluorescein angiography. The ACE gene I/D polymorphism was determined by polymerase chain reaction, and the ACE gene was classified into three types: I/I, I/D and D/D. In multivariate logistic regression analysis, ACE D/D genotype (p = 0.035), diabetes-mellitus (p = 0.019) and hypertension (p = 0.001) were found to be independent predictive factors for RVO. The results of the present study reveal that ACE D/D polymorphism is an independent predictive factor for RVO. However, one cannot definitely conclude that ACE gene polymorphism is a risk factor for retinal vein occlusion.

Angiotensin-converting enzyme I/D polymorphism and diabetic peripheral neuropathy in type 2 diabetes mellitus: A meta-analysis

BACKGROUND

Several molecular epidemiological studies have been conducted to examine the association between angiotensin-converting enzyme (ACE) I/D polymorphism and diabetic peripheral neuropathy (DPN) risk. However, the conclusions remained controversial. We therefore performed this meta-analysis.

METHODS

PubMed and EMBASE were searched to identify case-control studies investigating the associations of ACE I/D polymorphism with risk of DPN. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association between ACE I/D polymorphism and risk of DPN.

RESULTS

A total of seven case-control studies including 1316 cases and 1617 controls were included. ACE I/D polymorphism was associated with a significantly increased risk of DPN (OR=1.46, 95%CI 1.11-1.92, p=0.006, I(2)=48%). This result remained statistically significant when the adjusted ORs were combined (OR=1.84, 95%CI 1.14-2.99, p=0.01, I(2)=53%). In the subgroup of ethnicity, a significantly elevated risk was observed in Caucasians (OR=1.32, 95%CI 1.10-1.59, p=0.003, I(2)=43%).

CONCLUSIONS

Our meta-analysis confirmed that ACE I/D polymorphism was associated with the risk of DPN.

Gender specific association of RAS gene polymorphism with essential hypertension: a case-control study

Renin-angiotensin system (RAS) polymorphisms have been studied as candidate risk factors for hypertension with inconsistent results, possibly due to heterogeneity among various genetic and environmental factors. A case-control association study was conducted to investigate a possible involvement of polymorphisms of three RAS genes: AGT M235T (rs699), ACE I/D (rs4340) and G2350A (rs4343), and AGTR1 A1166C (rs5186) in essential hypertensive patients. A total of 211 cases and 211 controls were recruited for this study. Genotyping was performed using PCR-RFLP method. The genotype and allele distribution of the M235T variant differed significantly in hypertensives and normotensives (OR-CI = 2.62 (1.24–5.76), P = 0.006; OR-CI = 0.699 (0.518–0.943), P = 0.018), respectively. When the samples were segregated based on sex, the 235TT genotype and T allele were predominant in the female patients (OR-CI = 5.68 (1.60-25.10), P = 0.002; OR-CI = 0.522 (0.330–0.826), P = 0.005) as compare to the male patients (OR-CI = 1.54 (1.24–5.76), P = 0.34; OR-CI = 0.874 (0.330–0.826), P = 0.506), respectively. For ACE DD variant, we found overrepresentation of “I”-allele (homozygous II and heterozygous ID) in unaffected males which suggest its protective role in studied population (OR-CI = 0.401 (0.224–0.718); P = 0.0009). The M235T variant of the AGT is significantly associated with female hypertensives and ACE DD variant could be a risk allele for essential hypertension in south India.

Association of ACE I/D polymorphism with obstructive sleep apnea susceptibility: evidence based on 2,228 subjects

BACKGROUND

Whether the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene increases susceptibility to obstructive sleep apnea (OSA) is controversial and still undetermined. Therefore, this meta-analysis was performed to systematically assess the possible association between them.

METHODS

The OVID, Medline, Embase, Web of Science, CNKI, and Wangfang databases were searched to identify eligible studies focusing on the association between ACE polymorphism I/D and susceptibility to OSA.

RESULTS

A total of 2,228 subjects from nine studies were subjected to meta-analysis. Overall, ACE polymorphism I/D had no statistically significant association with increased OSA risk under all genetic models (P > 0.05). In the subgroup analysis by ethnicity or study design, still no significant associations were found for all genetic models (P > 0.05). However, ACE polymorphism I/D was significantly associated with susceptibility to OSA with hypertension in Asians under heterozygous comparison and dominant model. The ID genotype carriers and D allele carriers (ID + DD) were about 53% less likely (odds ratio (OR) = 0.47, 95% confidence interval (CI) = 0.29-0.74; P = 0.001) and about 52% less likely (OR = 0.48, 95% CI = 0.24-0.99; P = 0.047), respectively, to have OSA with hypertension compared to carriers of the II genotype.

CONCLUSIONS

ACE polymorphism I/D had no statistically significant association with increased OSA risk, but the II genotype of ACE may be a risk factor for OSA with hypertension in Asians. OSA cases who develop hypertension may derive from a different mechanism compared to essential hypertension. Studies with large sample size and representative population are warranted to verify this finding.

A meta-analysis of the association between angiotensin-converting enzyme insertion/ deletion gene polymorphism and the risk of overweight/obesity

BACKGROUND AND OBJECTIVE

The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) gene polymorphism and the risk of overweight/obesity remains controversial. A meta-analysis was conducted to evaluate the association between ACE I/D gene polymorphism and overweight/obesity susceptibility.

METHOD

All eligible studies were included in this meta-analysis by searching PubMed, Embase and Cochrane databases through April 2013 according to a predefined criteria.

RESULTS

Fourteen case-control studies including 3371 cases and 4490 controls were recruited for the analysis of the association between ACE I/D gene polymorphism and overweight/obesity susceptibility. A significant association was observed between DD genotype and overweight/obesity risk in overall populations and Africans (p=0.014 and 0.010, respectively). D allele was associated with the risk of overweight/ obesity in Africans (p=0.026). However, II genotype might not be a protective factor against overweight/obesity risk in overall populations, Africans, Caucasians and Asians.

CONCLUSIONS

DD genotype is a risk factor for the overweight/obesity susceptibility in overall populations, particularly in Africans. D allele is a risk factor for the overweight/obesity susceptibility in Africans. Further larger studies are needed to confirm our findings.

The ACE DD genotype and D-allele are associated with exceptional longevity: a meta-analysis

The ACE I/D polymorphism has been associated with longevity, although not consistently. The objective of this study was to detect the possible unequal distribution of the alleles and genotypes of this polymorphism among centenarians and younger segments of the population. Relevant data were extracted from studies in the literature, comparing genotype and allele frequencies between centenarians and younger controls. The association of ACE I/D polymorphism with exceptional longevity was analyzed in a total of 1803 centenarians and 10,484 controls using the chi-square test with the Yates correction. We conducted combined analyses for all ethnic groups studied in the literature (Caucasian, Chinese and Korean) as well as for Caucasians only. The DD genotype (odds ratio (OR): 1.25 (95% confidence interval (CI): 1.02-1.54), P=0.032) and the D-allele were more frequent in Caucasian centenarians compared with their younger controls (OR: 1.16 (95% CI: 1.05-1.28), P<0.001). Similar findings were obtained when all ethnic origin groups were included in the analyses, with no evidence of publication bias or heterogeneity (P>0.05). The present meta-analysis indicates that the ACE D-allele and the DD genotype might confer a modest, albeit significant advantage to reach exceptional longevity.

Angiotensin-converting enzyme insertion/deletion gene polymorphisms and risk of intracerebral hemorrhage: a meta-analysis of epidemiologic studies

Studies investigating the association between the intron 16 insertion/deletion (I/D) polymorphism (rs4646994) in the angiotensin-converting enzyme (ACE) gene and risk of intracerebral hemorrhage (ICH) have reported conflicting results. We here performed a meta-analysis based on the evidence currently available from the literature to make a more precise estimation of this relationship. Published literature from the National Library of Medline and Embase databases were retrieved. Odds ratios (OR) and 95% confidence limits (CLs) were calculated in fixed- or random-effects models when appropriate. Subgroup analyses were performed by race. This meta-analysis included six case-control studies, which included 744 ICH cases and 1411 controls. The combined results based on all studies showed that ICH cases had a significantly lower frequency of ID genotype (OR (codominant model) = 0.43, 95% CL = 0.22, 0.84, p = 0.01). In the subgroup analysis by race, we found that ICH cases had a significantly lower frequency of II genotype in Asians (OR (recessive model) = 0.50, 95% CL = 0.38, 0.66, p < 0.001; OR (codominant model) = 0.25, 95% CL = 0.09, 0.71, p = 0.009). In conclusion, our meta-analysis suggests that ACE I/D polymorphisms are associated with ICH, especially in Asians.