Analysis of the postulated interaction between the angiotensin II sub-type 1 receptor gene A1166C polymorphism and the insertion/deletion polymorphism of the angiotensin converting enzyme gene on risk of myocardial infarction

ACE I/D genotype associates with strength in sarcopenic men but not with response to ACE inhibitor therapy in older adults with sarcopenia: Results from the LACE trial

BACKGROUND

Angiotensin II (AII), has been suggested to promote muscle loss. Reducing AII synthesis, by inhibiting angiotensin converting enzyme (ACE) activity has been proposed as a method to inhibit muscle loss. The LACE clinical trial was designed to determine whether ACE inhibition would reduce further muscle loss in individuals with sarcopenia but suffered from low recruitment and returned a negative result. Polymorphic variation in the ACE promoter (I/D alleles) has been associated with differences in ACE activity and muscle physiology in a range of clinical conditions. This aim of this analysis was to determine whether I/D polymorphic variation is associated with muscle mass, strength, in sarcopenia or contributed to the lack of response to treatment in the LACE study.

METHODS

Sarcopenic individuals were recruited into a 2x2 factorial multicentre double-blind study of the effects of perindopril and/or leucine versus placebo on physical performance and muscle mass. DNA extracted from blood samples (n = 130 72 women and 58 men) was genotyped by PCR for the ACE I/D polymorphism. Genotypes were then compared with body composition measured by DXA, hand grip and quadriceps strength before and after 12 months' treatment with leucine and/or perindopril in a cross-sectional analysis of the influence of genotype on these variables.

RESULTS

Allele frequencies for the normal UK population were extracted from 13 previous studies (I = 0.473, D = 0.527). In the LACE cohort the D allele was over-represented (I = 0.412, D = 0.588, p = 0.046). This over-representation was present in men (I = 0.353, D = 0.647, p = 0.010) but not women (I = 0.458, D = 0.532, p = 0.708). In men but not women, individuals with the I allele had greater leg strength (II/ID = 18.00 kg (14.50, 21.60) vs DD = 13.20 kg (10.50, 15.90), p = 0.028). Over the 12 months individuals with the DD genotype increased in quadriceps strength but those with the II or ID genotype did not. Perindopril did not increase muscle strength or mass in any polymorphism group relative to placebo.

CONCLUSION

Our results suggest that although ACE genotype was not associated with response to ACE inhibitor therapy in the LACE trial population, sarcopenic men with the ACE DD genotype may be weaker than those with the ACE I/D or II genotype.

SARS-CoV-2 infections and COVID-19 mortalities strongly correlate with ACE1 I/D genotype

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COVID-19 infection is characterized by its prominent effect on specific ethnic group.

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SARS-CoV-2 cases/mortality were negatively associated with ACE1 II genotype.

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The ACE1 II genotype could be a predictive marker of SARS-CoV-2 risk and severity.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). The relentless spread and pathogenicity of the virus have become a global public health emergency. One of the striking features of this pandemic is the pronounced impact on specific regions and ethnic groups. In particular, compared with East Asia, where the virus first emerged, SARS-CoV-2 has caused high rates of morbidity and mortality in Europe. This has not been experienced in past global viral infections, such as influenza, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) and is unique to SARS-CoV-2. For this reason, we investigated the involvement of genetic factors associated with SARS-CoV-2 infection with a focus on angiotensin-converting enzyme (ACE)-related genes, because ACE2 is a receptor for SARS-CoV-2. We found that the ACE1 II genotype frequency in a population was significantly negatively correlated with the number of SARS-CoV-2 cases. Similarly, the ACE1 II genotype was negatively correlated with the number of deaths due to SARS-CoV-2 infection. These data suggest that the ACE1 II genotype may influence the prevalence and clinical outcome of COVID-19 and serve as a predictive marker for COVID-19 risk and severity.

Gene Polymorphisms of Angiotensin II Type 1 Receptor and Angiotensin-Converting Enzyme in Two Ethnic Groups Living in Zhejiang Province, China

Polymorphisms of ACE insertion/deletion (I/D) and angiotensin II type 1 receptor (AT1R) 1166A-C have been associated with many diseases, and distributions of their genotypes vary in different races and populations. The aim of this study was to investigate distributions of angiotensin-converting enzyme (ACE) and AT1R genotypes in Han and She populations in ZheJiang province. We determined ACE and AT1R genotypes in 189 Han and 163 She individuals. DNA was extracted from peripheral blood samples. Analyses of ACE and AT 1R genotypes were performed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The frequencies of ACE genotypes and alleles among the Han sample (41.3%II, 41.3%ID, 17.5%DD; 61.9%I allele, 38.1%D allele) were similar to those among She individuals (39.9%II, 39.3%ID, 20.9%DD; 59.5%I allele, 40.5%D allele), with p=0.660; p=0.421. However, significant differences in the distributions of ACE polymorphism between men and women among She population were observed, with p=0.042, p=0.014. AT1R genotype and allele frequencies in the Han population were (88.4%AA, 11.1%AC, 0.5%CC) and (93.9%A allele, 6.1%C) allele respectively. In the She population they were (78.0%AA, 21.3%AC, 0.6%CC) and (89.0%A allele, 11.0%C allele). The significant differences were found between Han and She populations with p=0.031, p=0.018, and within subgroups of women, with p=0.010, p=0.021. There were no significant differences within subgroups of men (p=0.476, p=0.261). The genotype distributions or allele frequencies of ACE and AT1R were significantly different between the samples of the She and Han populations.

Renin-angiotensin system gene polymorphisms and premature coronary heart disease

Introduction

Experimental and clinical studies demonstrated that the renin-angiotensin system (RAS) affects the pathogenesis of atherosclerosis and prognosis of coronary heart disease (CHD). The aim of this study was to investigate the genotype distribution and the allele frequencies of three RAS genes polymorphisms and their effects on premature CHD in a Turkish population.

Materials and methods

One-hundred and fifteen Turkish patients with premature CHD and 128 controls were included into the study. Angiotensin-converting enzyme (ACE), angiotensin II type 1 (AT1) receptor and angiotensinogen (AGT) gene polymorphisms were analysed by polymerase chain reaction (PCR ) and restriction fragment length polymorphism (RFLP).

Results

The patients group showed an increased frequency of the ACE D allele compared with controls (65% vs. 35%, p=0.0001). There was a significant association between the DD genotype and premature CHD (ACE DD vs. ID and II; odds ratio [OR]=2.82 [CI 95% 1.33—2.91, p=0.002]). Also, we observed increased premature CHD risk associated with higher frequencies of the AGT MM genotype in patients when compared with controls (AGT MM vs. TT and MT, OR=1.92 [CI 95% 1.11—3.33, p=0.018]). We found a significant association between AT1-receptor AA genotype and decreased risk of premature CHD (AT1R AA vs. AC and CC, OR= 0.57[CI 95% 0.34—0.95, p=0.03]).

Conclusions

We demonstrated that increased premature CHD risk is associated with higher frequencies of the ACE DD and AGT MM genotypes. These findings indicate a synergistic contribution of ACE DD and AGT MM polymorphisms to the development of premature CHD. Also, our results suggest that family history, smoking, diabetes, hypertension, obesity and ACE DD genotype were independent risk factors for premature CHD.

A systematic review and meta-analysis of the association between angiotensin II type 1 receptor A1166C gene polymorphism and myocardial infarction susceptibility

BACKGROUND AND AIM

Many reported studies have been conducted to investigate the association of angiotensin II type 1 receptor (AT1R) A1166C gene polymorphism with myocardial infarction (MI) susceptibility. However, the results from those reports are still conflicting. This meta-analysis was performed to study the relationship between AT1R A1166C gene polymorphism and MI risk.

METHOD

The databases of PubMed, Embase, and Cochrane Library were searched as of 1 March 2012, and eligible investigations were recruited into this meta-analysis.

RESULTS

Eighteen investigations were identified for the analysis of association between AT1R A1166C gene polymorphism and MI risk, 11 in Caucasians, three in Asians, two in Africans, one in the population of Brazil and one in the population of Durban, South Africa . There was a marked association between AT1R C allele and MI susceptibility for overall populations (odds ratio (OR)=1.12, 95% confidence interval (CI): 1.01-1.25, p=0.03), and AT1R AA genotype was associated with a lower risk of MI in overall populations (OR=0.87, 95% CI: 0.78-0.98, p=0.02). However, AT1R A1166C gene polymorphism was not associated with MI risk in the sub-groups of Caucasians, Asians, Africans, Brazil and Durban populations.

CONCLUSIONS

C allele is a risk factor for the MI susceptibility in overall populations, and AA genotype might be a protective factor against the MI risk in overall populations. However, more case-control association investigations on larger, stratified populations are required in the future.

A1166C genetic variation of the angiotensin II type I receptor gene and susceptibility to coronary heart disease: collaborative of 53 studies with 20,435 cases and 23,674 controls

OBJECTIVE

Angiotensin II induces vasoconstriction and vascular smooth muscle growth via stimulation of the angiotensin II type I receptor (AGTR1). Some studies have reported an association between a genetic variant (A1166C) in the 3' un-translated region of AGTR1 and increased risk of coronary heart disease (CHD), but other have yielded apparently conflicting results.

METHODS

Literature-based meta-analyses were performed on 48 papers including 53 studies published before June 2008 in relation to the A1166C polymorphism (NCBI, dbSNP: rs5186) of the AGTR1, involving a total of 20,435 CHD cases and 23,674 controls. We also explored potential sources of heterogeneity and conducted appropriate stratified analyses.

RESULTS

In a combined analysis, the per-allele odds ratio (OR) for CHD of the A1166C polymorphism was 1.11 (95% confidence interval: 1.03-1.19), but there is an indication of publication bias and heterogeneity among the 53 studies. Sample size and study quality were significant sources of heterogeneity among studies of the A1166C polymorphism with possibly overestimates in studies of smaller sample-size and poor-quality. When the analyses were restricted to 11 larger studies (≥500 cases), and to 8 high-quality studies (quality score: ≥11 points), the summary per-allele odds ratios were 0.992 (95% confidence interval, 0.944-1.042) and 0.990 (95% confidence interval, 0.915-1.072), respectively.

CONCLUSIONS

An overall weak association between the A1166C polymorphism and CHD is observed but this is likely to be due to publication bias and heterogeneity between studies. There were no significant associations among the larger sample-size and high-quality studies which are less prone to selective publication and have greater power to detect a true association.

Angiotensin-converting enzyme insertion/deletion gene polymorphism in a Tunisian healthy and acute myocardial infarction population

INTRODUCTION

The role of the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene (ACE) on acute myocardial infarction (AMI) is controversial.

OBJECTIVES

To assess the effect of the ACE I/D polymorphism on AMI compared with the healthy controls and its relationship with serum ACE activity in a Tunisian population.

DESIGN AND METHODS

A total of 119 patients with AMI were compared with 238 healthy controls from the same geographical area. ACE genotyping was determined by polymerase chain reaction, and serum ACE activity was measured with N-[3-(2-furylacryloyl]-L-phenylalanyl-L-glycyl-L-glycine as substrate.

RESULTS

The ACE I/D polymorphism was significantly different between patients and controls (p < 0.0001). The frequencies of the DD genotype and the D allele were statistically higher in patients with AMI as compared with the controls and were associated with increased risk of AMI (DD vs. ID and II: odds ratio = 4.27, p < 0.0001, 95% confidence interval = 2.65-6.86; D vs. I: odds ratio = 3.15, p < 0.0001, 95% confidence interval = 2.26-4.40). This association was independent of other cardiovascular risk factors but dyslipidemia (p = 0.002) that was not represented in AMI patients with II genotype and in a lower extent with hypertension (p < 0.05). Serum ACE activity was significantly higher in AMI patients with ACE DD genotype compared with the subjects with ID or II genotype (p = 0.034) and was not correlated with other cardiovascular risk factors.

CONCLUSIONS

ACE DD genotype associated with higher serum ACE activity is increased in the studied population and might be clinically useful as markers to assess risk for AMI.

Angiotensin-converting enzyme gene insertion/deletion polymorphism in Egyptian patients with myocardial infarction

Introduction. This work aimed to test the association of the angiotensin-converting enzyme gene insertion/deletion (I/D) polymorphism with myocardial infarction.

Subjects and methods. This study comprised 79 Egyptian myocardial infarction cases with a mean age of 54.4±9.9 years including 60 males and 19 females, plus 238 healthy unrelated individuals of nearly matched age and sex as a control group. For all subjects, DNA testing for the angiotensin-converting enzyme gene I/D polymorphism was done using PCR amplification for detection of both the D and I alleles followed by a second run PCR specific for the I allele for samples typed as DD in the first run.

Results. Cases had a higher frequency of DD (29.1%) and ID (62.0%) genotypes than II (8.9%) genotype, with a higher frequency of D allele than I allele (64.4% vs. 33.6%). Compared to controls, cases had a significantly higher frequency of ID genotype (62.0% vs. 47.5%, p<0.05).This was more apparent among cases in the low risk group (p=0.002) than in the high risk group (p=0.041).

Conclusion. The angiotensin-converting enzyme gene I/D polymorphism is probably a risk factor for ischaemic heart disease among Egyptian cases, particularly if integrated with other environmental and genetic risk factors.

Angiotensin II type 1 receptor polymorphisms and susceptibility to hypertension: a HuGE review

The angiotensin II type 1 receptor (AGTR1) plays an integral role in blood pressure control, and is implicated in the pathogenesis of hypertension. Polymorphisms within this gene have been extensively studied in association with hypertension; however, findings are conflicting. To clarify these data, we conducted a systematic review of association studies of AGTR1 polymorphisms and hypertension, and performed a meta-analysis of the rs5186 variant. Results show that the currently available literature is too heterogeneous to draw meaningful conclusions. The definition of hypertension and gender composition of individual studies helps to explain this heterogeneity. Although the structure and splicing pattern of AGTR1 would suggest a likely effect of polymorphisms within the promoter region on gene function, few studies have been conducted thus far. In conclusion, there is insufficient evidence that polymorphisms in the AGTR1 gene are risk factors for hypertension. However, most studies are inadequately powered, and larger well-designed studies of haplotypes are warranted.

The geographic distribution of the ACE II genotype: a novel finding

Angiotensin converting enzyme (ACE) gene polymorphism insertion (I) or deletion (D) has been widely studied in different populations, and linked to various functional effects and associated with common diseases. The purpose of the present study was to investigate the relationship between the ACE I/D frequency in different populations and geographic location; ACE I/D allele frequency in the Lebanese population and ACE II genotype contribution to the geographic trend were also identified. Five hundred and seventy healthy volunteers were recruited from the Lebanese population. Genomic DNA was extracted from buccal cells, and amplified by polymerase chain reaction; products were then identified by gel electrophoresis. The frequencies of the different ACE I/D genotypes were determined and tested for Hardy-Weinberg equilibrium (HWE). To assess the relationship between ACE I/D frequency and geographic location, and to identify how the Lebanese population contributes to the geographic trend in ACE I/D frequencies, Eurasian population samples and Asians were incorporated in the analyses from the literature. The frequency of the I allele in the Lebanese population was 27% and the corresponding II genotype was at a frequency of 7.37% (in HWE; P=0.979). The ACE I allele and genotype frequencies show an association with longitude, with frequencies increasing eastwards and westwards from the Middle East.

Polymorphisms of the renin-angiotensin system genes predict progression of subclinical coronary atherosclerosis

Premature coronary artery disease (CAD) in subjects with type 1 diabetes dramatically affects quality of life and morbidity and leads to premature death, but there is still little known about the mechanisms and predictors of this complication. In the present study, we explored the role of genetic variants of angiotensinogen (AGT, M235T), ACE (I/D), and angiotensin type 1 receptor (ATR1, A1166C) as predictors of rapid progression of subclinical coronary atherosclerosis. Five-hundred eighty-five type 1 diabetic patients and 592 similar age and sex control subjects were evaluated for progression of coronary artery calcification (CAC), a marker of subclinical CAD, before and after a 2.5-year follow-up. In logistic regression analysis, CAC progression was dramatically more likely in type 1 diabetic subjects not treated with ACE inhibitor/angiotensin receptor blocker who had the TT-ID-AA/AC genotype combination than in those with other genotypes (odds ratio 11.6 [95%CI 4.5-29.6], P < 0.0001) and was even stronger when adjusted for cardiovascular disease risk factors and the mean A1C (37.5 [3.6-388], P = 0.002). In conclusion, a combination of genotype variants of the renin-angiotensin system genes is a powerful determinant of subclinical progression of coronary artery atherosclerosis in type 1 diabetic patients and may partially explain accelerated CAD in type 1 diabetes.

ACE-DD genotype is associated with the occurrence of acute coronary syndrome in postmenopausal women

The insertion/deletion (I/D) polymorphism of the angiotensin converting enzyme (ACE), the A1166C polymorphism in the angiotensin type 1 receptor (AT1R), and the M235T polymorphism of the angiotensinogen gene are associated with cardiovascular disease mostly in men. Few data are available on the effects of these genetic variations in postmenopausal women according to hormone replacement therapy (HRT) use. In this case-control study, we determine the frequency of mutant alleles in the ACE I/D, M235T and A1166C polymorphisms in postmenopausal Caucasian women with and without a diagnosis of acute coronary syndrome (ACS). Data from 198 women with ACS (63+/-10 years) and 149 controls (62+/-7 years) showed that ACE-DD genotype was more prevalent in women with ACS compared to controls (30% vs. 19%, P<0.05). There was no difference in genotype distributions for either the M235T or the A1166C polymorphisms between groups. The difference in ACE genotype distribution between ACS women and controls was driven by current HRT users with 30% of ACS and 15% of controls carrying the ACE-DD genotype (P<0.05). The oligenic combination of ACE-DD and M235T-TT genotypes was higher in ACS compared to controls. Among carriers of M235T-TT, 7% of ACS and 1% of controls also had the ACE-DD genotype, P<0.05. Thus, the ACE-DD genotype may be associated with ACS in postmenopausal women, particularly in HRT users.

Angiotensin Converting Enzyme and Angiotensin II Type 1 Receptor Polymorphisms in Patients with Coronary Aneurysms

BACKGROUND: Conflicting results have been reported regarding the association of gene polymorphisms in the renin-angiotensin system (RAS) with different aspects of coronary artery disease (CAD), such as myocardial infarction, neointimal hyperplasia or coronary artery vasomotion. Since previous studies have linked angiotensin II to aneurysmal disease, our study hypothesis was that RAS gene polymorphisms may be associated with aneurysm remodeling in response to CAD. METHODS: The study population was selected from a series of 3862 consecutive patients who underwent coronary angiography in our institution. One hundred and thirteen consecutive patients with at least one coronary aneurysm (CA) were compared to 226 randomized control patients without CA. DNA was extracted from white blood cells. The angiotensin-converting enzyme (ACE) I/D and angiotensin type 1 receptor (AT1-R) A/C polymorphisms were detected using previously published techniques. RESULTS: The distributions of the three ACE genotypes were similar in both groups: CA: 13%, 46%, and 41% for II, ID, and DD respectively; controls: 18%, 41%, and 41% for II, ID, and DD respectively, p = 0.45. The distributions of the three AT1-R genotypes were also similar in both groups: CA: 54%, 41%, and 5% for AA, AC, and CC respectively; controls: 55%, 33%, and 12%, for AA, AC, and CC respectively, p = 0.08. CONCLUSION: Our results provide further information on the role of RAS polymorphisms on specific mechanisms implicated in CAD. Although an activated RAS may theoretically promote aneurysm formation, the 2 RAS polymorphisms analyzed in this study are not associated with this process in coronary arteries.

Pharmacogenomics of primary hypertension--the lessons from the past to look toward the future

A number of recent reviews have addressed the issue of the pharmacogenomics of primary hypertension and related complications by considering the data on the genotype-drug response relationship. Here we mainly discuss the methodological aspects of this issue, trying to integrate 'traditional' clinical and experimental pathophysiology and therapy-pharmacology with the 'new' genetics. Such integration is indispensable to: a). define the appropriate 'context' (genetic background, environment, age, gender, phase of hypertension, previous therapy etc.) in which a given genotype-drug response relationship should be tested (it is indeed likely that many discrepancies among published data originate from context's interference); b). assign the correct clinical meaning to the results obtained by statistics and functional genetics methodologies; c). define a novel clinical entity caused by a disease favoring allele, alone or in combination with other alleles, with a consistent clinical picture, prognosis and responsiveness to the appropriate drug; d). estimate the size of the population target amenable to benefit from a therapeutic intervention developed according to the pharmacogenomics' principles; e). develop a novel drug that selectively interferes with the sequence of events triggered by the genetic mechanism(s) underlying the clinical entity. Peculiar to this strategy is to look for consistency among findings gathered from different 'contexts' after having properly accounted for the context's dependency of the results.

Oxidized LDL receptor gene (OLR1) is associated with the risk of myocardial infarction

Lectin-like oxidized low-density lipoprotein receptor (LOX-1/OLR1) has been suggested to play a role in the progression of atherogenesis. We analyzed the OLR1 gene and found a single nucleotide polymorphism (SNP), G501C, in patients with ischemic heart disease from a single family, which resulted in the missense mutation of K167N in LOX-1 protein. We compared the group of patients with myocardial infarction (MI) (n=102) with a group of clinically healthy subjects (n=102), and found that the MI group had a significantly high frequency of 501G/C+501C/C (38.2%) compared with the healthy group (17.6%; p<0.002). The odds ratio for the risk of MI associated with the 501G/C+501C/C genotype was 2.89 (95% CI, 1.51-5.53). These findings suggest that OLR1 or a neighboring gene linked with G501C SNP is important for the incidence of MI. Manipulating LOX-1 activity might be a useful therapeutic and preventative approach for coronary artery disease, especially for individuals with the G501C genotype of OLR1.

Angiotensin-converting enzyme gene polymorphism interacts with left ventricular ejection fraction and brain natriuretic peptide levels to predict mortality after myocardial infarction

OBJECTIVES

The goal of this study was the exploration of the associations between the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and post-myocardial infarction (MI) outcomes, especially any interaction with the accepted clinical prognostic markers brain natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF).

BACKGROUND

The ACE gene I/D polymorphism has been implicated in the development of MI, hypertension, and left ventricular hypertrophy. We examined the association of ACE I/D and prognosis after acute MI.

METHODS

Patients incurring acute MI were genotyped for the ACE I/D polymorphism. Clinical data included assays of neurohormones, radionuclide ventriculography, and mortality over a mean 2.6 years of follow-up.

RESULTS

Patients (n = 978) had a mean age of 62.1 years, and 78% were male. Overall genotype frequencies were II 23.2%, ID 49.5%, and DD 27.3%. Chi-square analysis revealed an association between the ACE D allele and death after MI (88 of 103 who died were DD or ID; p < 0.05), with an odds ratio for mortality of 8.03 (95% confidence interval, 2.16 to 29.88). Patients with the DD genotype had higher (p < 0.05) plasma BNP, N-terminal BNP (N-BNP), and endothelin-1 levels within 96 h after MI than grouped ID/II patients. Multivariate analysis indicated ACE genotype, age, and previous MI were independent predictors of death (p < 0.05). Patients with an ACE D allele in combination with either a lower than median LVEF or greater than median BNP had a higher mortality (p < 0.001 and p < 0.025, respectively) than the risk associated with the D allele itself.

CONCLUSIONS

Angiotensin-converting enzyme genotyping may provide additional prognostic information in patients after MI in combination with the proven utility of LVEF, plasma BNP, and N-BNP measurements.

Effects of ACE I/D and AT1R-A1166C polymorphisms on blood pressure in a healthy normotensive primary care population: first results of the Hippocates study

BACKGROUND

Several studies have assessed the relationship between the angiotensin-converting enzyme (ACE) I/D or angiotensin II type 1 receptor (AT(1)R)-A C polymorphisms and blood pressure (BP). Since most data have been obtained in selected populations, the present study was performed in a healthy normotensive primary care population.

OBJECTIVE

To investigate the individual effects of the aforementioned polymorphisms and their interaction on BP.

METHODS

This cross-sectional study included 198 healthy subjects. Office BP was measured and polymorphisms were genotyped (polymerase chain reaction). Polymorphism interaction was tested using the following model: systolic blood pressure (SBP) (or diastolic blood pressure, DBP) = b(0)+ b(1)X + b(2)Y + b(3)XY, in which X and Y represent the polymorphisms' risk alleles.

RESULTS

The ACE I/D polymorphism was associated with SBP (P = 0.002) and DBP (P = 0.004); highest pressures tracked with the DD genotype. Furthermore, in multiple linear regression analysis the ACE D allele was associated with SBP (P = 0.005) and DBP (P = 0.001), when adjusted for body mass index (BMI) and age. With respect to the AT(1)R-A C polymorphism, SBP was highest in the CC genotype (P = 0.025). In linear regression analysis the C allele was not associated with SBP. No synergistic effect of ACE D and AT(1)R C alleles on BP was found. Nevertheless, highest DBP tracked with the DDCC combination in comparison with other homozygous allele combinations (P = 0.030).

CONCLUSIONS

This study confirmed an association of ACE I/D and AT(1)R-A C polymorphisms with BP in a healthy normotensive primary care population. Although synergistic effect of both polymorphisms on BP does not seem to be present, an additive effect on DBP is likely.

Angiotensin II receptor polymorphisms in hypertension. Pharmacogenomic considerations

Molecular variants of individual components of the renin-angiotensin system (RAS) are thought to contribute to inherited predisposition towards essential hypertension. Polymorphisms in genes of angiotensinogen (AGT), angiotensin I-converting enzyme (ACE) and angiotensin II type 1 receptor (AT-1) have been related to differential responses to antihypertensive drugs. AT-1 receptor mediates the major pressor and trophic actions of angiotensin II (Ang II). At least 14 AT-1 polymorphisms have been described in the gene (AGT1R); in particular the +1166 A/C polymorphism has been associated with the severe form of essential hypertension. A relationship was suggested between this polymorphism and the humoral and renal hemodynamic responses to losartan, an antihypertensive drug acting as an AT-1 blocker. Variability in the individual response to AT-1 antagonists could also be due to variations in the pharmacokinetics of the drugs. This review presents current knowledge on Ang II-receptors and polymorphisms in AGT1R related to cardiovascular disease and antihypertensive therapy.