Association of the angiotensin-converting enzyme (ACE) gene G2350A dimorphism with essential hypertension

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.

Diagnostic efficacy of cystatin-c in association with different ACE genes predicting renal insufficiency in T2DM

Diabetic nephropathy (DN) seems to be the major cause of chronic kidney disease that may finally lead to End Stage Renal Disease. So, renal function assessment in type 2 diabetes mellitus (T2DM) individuals is very important. Clearly, DN pathogenesis is multifactorial and different proteins, genes and environmental factors can contribute to the onset of the disease. We assessed sensitive and specific biomarkers (in blood and urine) which can predict kidney disease susceptibility among T2DM patients. Serum cystatin-c (cyst-c) in blood and urinary hemeoxygenase (HO-1) in addition to ACE I/D polymorphism and ACE G2350A genotypes. Hundred and eight T2DM patients and 85 controls were enrolled. Serum cystatin-c and urinary (HO-1) were tested by ELISA. Genetic determination of both ACE I/D polymorphism and ACE G2350A genotypes was performed by PCR for all participants. Significant rise in serum cystatin-c and urinary HO-1 levels were shown in diabetic groups compared with control group. Moreover, GG genotype of ACE G2350A gene in diabetic group was associated with rise in serum cystatin-c and urinary HO-1 compared with control group. Mutant AA genotype demonstrated increase in urinary HO-1. DD polymorphism was associated with rise in serum creatinine and cyst-c in diabetic group. Positive correlation was seen between duration of diabetes and serum cyst-c and between serum glucose and urinary (HO-1) in diabetic group. The results from this study indicated an association of serum cystatin-c with GG genotype of ACE G2350A in conjugation with DD polymorphism of ACE I/D which could be an early predictor of tubular injury in T2DM diabetic patients.

SNPs of ACE1 (rs4343) and ACE2 (rs2285666) genes are linked to SARS-CoV-2 infection but not with the severity of disease

COVID-19 and the renin-angiotensin system (RAS) are linked by angiotensin-converting enzyme 2 (ACE2), a key enzyme in RAS that has been validated as a SARS-CoV-2 receptor. Functional ACE1/ACE2 gene polymorphisms may lead to the imbalance between ACE/ACE2 ratio and thus generating RAS imbalance that is associated with higher degrees of lung damage in ARDS that may contribute to the COVID-19 infection outcome. Herein, we investigated the role of RAS gene polymorphisms, ACE1 (A2350G) and ACE2 (G8790A) as risk predictors for susceptibility and severity of COVID-19 infection. A total of 129 included: negative controls without a history of COVID-19 infection (n = 50), positive controls with a history of COVID-19 infection who were not hospitalized (n = 35), and patients with severe COVID-19 infection who were hospitalized in the intensive care unit (n = 44). rs4343 of ACE and rs2285666 of ACE2 were genotyped using PCR-RFLP method. Our results indicated that susceptibility to COVID-19 infection was associated with age, GG genotype of A2350G (Pa = 0.01; OR 4.7; 95% CI 1.4-15.1 and Pc = 0.040; OR 2.5; 95% CI 1.05-6.3) and GG genotype of G8790A (Pa = 0.044; OR 6.17; 95% CI 1.05-35.71 and Pc = 0.0001; OR 5.5; 95% CI 2.4-12.4). The G allele of A2350G (Pa = 0.21; OR 1.74; 95% CI 0.73-4.17 and Pc = 0.007; OR 2.1; 95% CI 1.2-3.5) and G allele of G8790A (Pa = 0.002; OR 4.26; 95% CI 1.7-10.65 and Pc = 0.0001; OR 4.7; 95% CI 2.4-9.2) were more frequent in ICU-admitted patients and positive control group. Also lung involvement due to COVID-19 infection was associated with age and the comorbidities such as diabetes. In conclusion, our findings support the association between the wild genotype (GG) of ACE2 and homozygote genotype (GG) of ACE1 and sensitivity to COVID-19 infection, but not its severity. However, confirmation of this hypothesis requires further studies with more participants.

Evaluation of the effect of serum cystatin-C and ACE I/D and ACE G2350A polymorphisms on kidney function among hypertensive sewage workers

Cadmium (Cd) as nephrotoxicant metal exerts its potent effect mainly on renal tubules disturbing its functions. A cross-sectional study was conducted on 55 sewage workers occupationally exposed to Cd and 50 control subjects. The study aimed to assess the effect of low-level Cd exposure on blood pressure and renal function in terms of serum cystatin-C levels. The associations between genetic polymorphisms of ACEI/D and ACE G2350A and hypertension and tubular injury among workers were studied. We analyzed blood and urine Cd concentration (U-Cd), serum cystatin-C, ACE I/D polymorphisms, and ACE G2350A, and blood pressure was measured. Results recorded a significant rise in serum and U-Cd and cystatin-C levels in sewage workers compared with controls. Significant distribution in genotype frequency of ACE I/D and ACE G2350A gene was detected. An association in DD genotype of ACE I/D with a rise in serum and U-Cd was observed in workers. In wild type genotype GG of ACE G2350A gene, a significant rise in serum cystatin-C levels and diastolic pressure was found while in heterozygote genotype GA significant rise in U-Cd levels was detected. Also, the association of AA genotype of ACE G2350A gene with a significant rise in serum and U-Cd and cystatin-C levels was shown among workers compared with control groups. Our findings indicated an association of ACE DD polymorphism in conjugation with GG genotype of ACE2 with hypertension and tubular injury in sewage workers.

The Gene Polymorphism of Angiotensin-Converting Enzyme Intron Deletion and Angiotensin-Converting Enzyme G2350A in Patients With Left Ventricular Hypertrophy: A Meta-analysis

Objectives

The aim of the study was to evaluate the correlation between left ventricular hypertrophy and the gene polymorphism of angiotensin-converting enzyme (ACE) intron deletion (I/D) and ACE G2350A.

Methods

Information related to the sample size and genotype frequencies was extracted from each study.

Results

Our results found that the D allele (p = 0.0180) and DD genotype (p = 0.0110) of ACE I/D had a significant association with increasing the risk of left ventricular hypertrophy, whereas the I allele (p = 0.0180), but not II (p = 0.1660) and ID genotypes (p = 0.1430), was associated with decreasing the risk of left ventricular hypertrophy. On other hand, we found that the A allele (p = 0.0020) and GA genotype of ACE G2350A (p = 0.0070) had the correlation with increasing the risk of left ventricular hypertrophy.

Conclusions

Our meta-analysis reveals that the D allele of ACE I/D and the A allele of ACE G2350A are associated with increasing the risk of left ventricular hypertrophy.

Association of angiotensin-converting enzyme G2350A gene polymorphisms with hypertension among patients with intracerebral haemorrhage

OBJECTIVES

To evaluate the correlation of angiotensin-converting enzyme (ACE) G2350A gene polymorphisms with hypertension, brain hematoma volume (BHV), level of consciousness, and disease outcome among intracerebral haemorrhage (ICH) patients.

METHODS

A cross-sectional study was conducted in Zainoel Abidin General Hospital from May 2016 to June 2017. Polymerase chain reaction was used to genotype ACE G2350A gene polymorphisms. BHV was assessed using the ABC/2 volume estimation formula. Level of consciousness was assessed by Glasgow coma scale (GCS). Disease outcome was assessed using Glasgow outcome scale (GOS). Association tests for ACE G2350A genotype in the context of hypertension status, BHV, GCS score, and GOS score in subjects with ICH was analysed by multiple logistic regression.

RESULTS

A total of 75 ICH patients were included in the study. Of those, 59 patients exhibited hypertension, 24 patients had BHV ≥60 cm3, 16 patients possessed GCS scores ≤8, and 72 patients had GOS scores of 1-3. Our analysis determined that the A allele of the ACE G2350A gene polymorphism was significantly associated with a 3.6-fold increase in hypertension; however, this polymorphism was not associated with BHV, level of consciousness, and disease outcome among ICH patients.

CONCLUSION

The A allele of the ACE G2350A gene polymorphisms is associated with hypertension among ICH patients.

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).

Correlation between renin-angiotensin system gene polymorphisms and essential hypertension in the Chinese Yi ethnic group

INTRODUCTION

The renin-angiotensin system (RAS) has been considered to play an important role in the regulation of blood pressure. This study aimed to investigate the correlation between RAS gene polymorphisms and essential hypertension (EH) in the Chinese Yi ethnic group.

MATERIALS AND METHODS

A total of 244 EH subjects and 185 normotensive individuals from the Chinese Yi ethnic group were genotyped for AGT M235T (rs699), AT1R A1166C (rs5186), ACE I/D (rs4340) and ACE G2350A (rs4343) polymorphisms by the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method.

RESULTS

Significant differences in the allele and genotype frequency of ACE G2350A were observed between the EH cases and controls (p=0.001, 0.002). After being grouped by gender, significant differences in the allele and genotype frequency of ACE G2350A and AT1R A1166C were observed between females of the EH cases and controls (ACE G2350A: p=0.000, 0.002; AT1R A1166C: p=0.008, 0.011). After excluding the influence of multifactorial interactions, the ACE G2350A polymorphism is significantly associated with the pathogenesis of EH in the Chinese Yi ethnic group (odds ratio (OR)=1.656, 95% confidence interval (CI) 1.807-2.524, p=0.019).

CONCLUSIONS

The RAS-related ACE G2350A polymorphism is associated with the pathogenesis of EH in the Chinese Yi ethnic group.

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.

The effects of angiotensinogen gene polymorphisms on cardiovascular disease outcomes during antihypertensive treatment in the GenHAT study

Previous studies have reported that risk of cardiovascular morbidity and mortality substantially increases in hypertensive patients, especially among those with inadequate blood pressure control. Two common antihypertensive drug classes including thiazide diuretics and angiotensin-converting enzyme (ACE) inhibitors affect different enzymes in the renin-angiotensin-aldosterone system (RAAS). In the RAAS, angiotensinogen is converted into angiotensin II which increases blood pressure through vasoconstriction. Using a case-only design with 3448 high-risk hypertensive individuals from the Genetics of Hypertension Associated Treatment (GenHAT) study, we examined whether seven single nucleotide polymorphisms (SNPs) in the angiotensinogen gene (AGT) interact with three classes of antihypertensive drugs including chlorthalidone (a thiazide diuretic), lisinopril (an ACE inhibitor), and amlodipine (a calcium channel blocker) to modify the risk of incident coronary heart disease (CHD) and heart failure (HF) among Caucasian and African American participants, separately. We found no gene by treatment interactions to be statistically significant after correction for multiple testing. However, some suggestive results were found. African American participants with the minor allele of rs11122576 had over two-fold higher risk of CHD when using chlorthalidone compared to using amlodipine, or lisinopril compared to amlodipine (p = 0.006 and p = 0.01, respectively). Other marginal associations are also reported among both race groups. The findings reported here suggest that rs11122576 could contribute to future personalization of antihypertensive treatment among African Americans though more studies are needed.

Gender specificity of a genetic variant of angiotensin-converting enzyme and risk of coronary artery disease

Etiological factors for coronary artery disease (CAD) involve a wide range of gene and environmental interactions. One of the systems being implicated in the pathophysiology of CAD is the renin-angiotensin system (RAS). However, the genetic polymorphisms of this system have not been widely studied in Iranian patients diagnosed with CAD. The aim of this study was to assess the relationship between six gene polymorphisms of RAS components and CAD in a sample of Iranian population. A total of 374 participants were enrolled in a case/control study. The presence of CAD was determined by coronary angiography. Genotyping of six RAS gene polymorphisms was performed using a modified PCR-RFLP method. Our results revealed, for the first time, a significant independent association of angiotensin-converting enzyme (ACE) A-240T polymorphism and incidence of CAD among Iranian women (P=0.005, OR=20.4, 95% CI=2.49-41.2). There has also been a significant difference in genotype distribution of ACE A-240T (P=0.008) and angiotensin II receptor type 2 C3123A polymorphism (P=0.032) in Iranian female participants. In conclusion, TT genotype of ACE A-240T seems to be a genetic risk factor for CAD in Iranian women.

Association of angiotensin-converting enzyme (ACE) gene polymorphism with elevated serum ACE activity and major depression in an Iranian population

Genetic factors contribute substantially to the likelihood of developing major depressive disorder (MDD). The importance of renin-angiotensin system (RAS) elements in cognition and behaviour and their involvement in aetiology and treatment of depression imply that RAS gene polymorphism(s) associated with RAS overactivity might also be associated with depression. In the present study, genotype and allele frequencies of six common polymorphisms of genes encoding for RAS components were determined in DNAs extracted from venous blood of 191 depressed and 104 healthy individuals using polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and serum angiotensin-converting enzyme (ACE) activity was assayed using a high-performance liquid chromatography (HPLC) method. The results showed, for the first time, that GG genotype of ACE A2350G was significantly associated with MDD among Iranian participants (P=0.001; odds ratio (OR)=6.2; 95% confidence interval (CI)=2.1-18.3). Significant higher serum ACE activity (P=0.0001) as well as higher diastolic blood pressure (P=0.036) were observed in depressed patients compared to the healthy control group. Depressed patients carrying GG genotype of the A2350G polymorphism had a significantly higher serum ACE activity (P=0.02) than individuals with either AA or AG genotype. In conclusion, this study supports the hypothesis of RAS overactivity in depression in that the genotype associated with higher serum ACE activity in an Iranian population was also associated with MDD.

Association of angiotensin-converting enzyme polymorphism with coronary artery disease in Iranian patients with unipolar depression

OBJECTIVES

Major depressive disorder (MDD) is an increasingly recognized risk factor of coronary artery disease (CAD). The aim of this study was to assess the relationship between renin-angiotensin system (RAS) genetic polymorphisms and CAD in a sample of depressed Iranian patients.

DESIGN AND METHODS

A total of 191 patients with a history of unipolar depression were enrolled in a case/control study. The presence of MDD was reconfirmed at study entry using DSM-IV criteria and CAD was diagnosed by coronary angiography. Genotyping of six RAS genes polymorphisms was performed by a modified PCR-RFLP method.

RESULTS

DD genotype of ACE I/D was independently associated with the incidence of CAD in depressed patients (P=0.011, OR=9.41, 95% CI: 1.68-17.81). Moreover, serum creatinine (P=0.033, OR=11.91, 95%CI: 7.23-15.62) was an independent predictor of CAD among depressed individuals.

CONCLUSION

ACE I/D polymorphism may play a major role in the development of CAD amongst Iranian depressed patients.

Influences of the G2350A polymorphism in the ACE gene on cardiac structure and function of ball game players

Background

Except for the I/D polymorphism in the angiotensin I-converting enzyme (ACE) gene, there were few reports about the relationship between other genetic polymorphisms in this gene and the changes in cardiac structure and function of athletes. Thus, we investigated whether the G2350A polymorphism in the ACE gene is associated with the changes in cardiac structure and function of ball game players. Total 85 healthy ball game players were recruited in this study, and they were composed of 35 controls and 50 ball game players, respectively. Cardiac structure and function were measured by 2-D echocardiography, and the G2350A polymorphism in the ACE gene analyzed by the SNaPshot method.

Results

There were significant differences in left ventricular mass index (LVmassI) value among each sporting discipline studied. Especially in the athletes of basketball disciplines, indicated the highest LVmassI value than those of other sporting disciplines studied (p < 0.05). However, there were no significant association between any echocardiographic data and the G2350A polymorphism in the ACE gene in the both controls and ball game players.

Conclusions

Our data suggests that the G2350A polymorphism in the ACE gene may not significantly contribute to the changes in cardiac structure and function of ball game players, although sporting disciplines of ball game players may influence the changes in LVmassI value of these athletes. Further studies using a larger sample size and other genetic markers in the ACE gene will be needed.

Interaction of A-240T and A2350G related genotypes of angiotensin-converting enzyme (ACE) is associated with decreased serum ACE activity and blood pressure in a healthy Iranian population

Most of renin-angiotensin system (RAS) gene polymorphisms have not yet been studied in the Iranian population. In the present study, the frequencies of common polymorphisms in the RAS genes, including angiotensin-converting enzyme (ACE) insertion/deletion (I/D) and three single-nucleotide polymorphisms (SNPs), i.e., A-240T, T-93C and A2350G, angiotensinogen M235T, angiotensin II receptor type 1 A1166C and angiotensin II receptor type 2 C3123A variants were determined in DNAs extracted from venous blood of 104 healthy Iranian volunteers. Genotyping was performed by PCR-RFLP method. Serum ACE activity was also assayed using reverse phase HPLC. Combined polymorphisms of TT (A-240T) and GG (A2350G) was significantly associated with decreased serum ACE activity (P=0.042) and decreased diastolic blood pressure (P=0.040). The angiotensin II receptor type 1 A1166C polymorphism (CC genotype) showed a significant association with declined diastolic blood pressure (P=0.028). Serum ACE activity was significantly higher in men compared to women (P=0.033). ACE activity also showed a direct association with diastolic blood pressure (P<0.001). No association was obtained among each single polymorphism with body mass index (BMI), fasting blood sugar (FBS), lipid profile and ACE activity. In conclusion, combined polymorphisms of A-240T and A2350G seem to affect serum ACE level as well as diastolic blood pressure in our study population. However, it also might be hypothesized that they are in strong linkage disequilibrium with other functional mutations not studied yet. Our findings revealed that gene interactions can play an important role in various biological conditions.

Association of ACE ID and ACE G2350A polymorphism with increased blood pressure in persons exposed to different sound levels in Pakistan

PURPOSE

To investigate the role of ACE ID and ACE G2350A polymorphism in increasing the blood pressure of persons exposed to different sound levels.

METHOD

Persons exposed to normal sound level (≤80 dBA) and noise (>80 dBA) were divided in two categories on the basis of blood pressure. Category A was comprised of the individuals with blood pressure ranges equal or less than that for normotensive persons. Category B was composed of the workers with blood pressure above than that for category A. ACE ID and ACE G2350A polymorphism was detected for analysis of its association with the increased blood pressure considering noise as modifier.

RESULTS

Least homozygous allele model for ACE ID polymorphism indicates no association of DD allele with the increased blood pressure in persons exposed to normal sound (Odds ratio: 0.831; 95% Confidence interval: 0.340-2.030). Similar findings were noted in persons exposed to noise (Odds ratio: 0.992; 95% Confidence interval: 0.536-1.835). Combining all the samples did not change the results (Odds ratio: 0.948; 95% Confidence interval: 0.580-1.549). For ACE G2350A polymorphism, least common homozygote model revealed that AA allele did not affect the chances of increased blood pressure in normal sound exposed group (Odds ratio: 0.827; 95% Confidence interval: 0.169-4.042) and noise exposed group (Odds ratio: 1.416; 95% Confidence interval: 0.682-2.941). There was no prominent variation in the results on combining all the samples (Odds ratio: 1.529; 95% Confidence interval: 0.807-2.872).

CONCLUSIONS

No association was observed between ACE ID/ACE G2350A polymorphism and the increased blood pressure in persons exposed to normal sound and noise in Pakistani population.

Review: Association between angiotensin converting enzyme G2350A polymorphism and hypertension risk: a meta-analysis

Background and objective: An exonic polymorphism G2350A (rs4343) in angiotensin converting enzyme (protein: ACE; gene: ACE) was shown to exert the most significant influence on plasma ACE levels. We therefore performed a meta-analysis to investigate association of ACE G2350A polymorphism with hypertension.

Methods: Published case-control studies in English were identified. A total of four studies with 1699 cases and 1274 controls were identified. A random-effects model was performed irrespective of the between-study heterogeneity. Study quality was assessed in duplicate.

Results: Compared with 2350G, the ACE 2350A allele conferred a protective effect on hypertension (odds ratio (OR) = 0.81; 95% confidence interval (CI), 0.56—1.18; p = .28). Similarly, comparisons of 2350AA and 2350GA with 2350GG generated a nonsignificant reduced risk, respectively. Under the dominant model, the ACE 2350A allele conferred a reduced hypertension risk and such associations were divergent between Han Chinese and Muslims from the Arab Gulf and Pakistan. Under the recessive model, this protective effect was totally reversed (OR = 1.01; 95% CI, 0.77—1.33; p = .94). Subgroup analyses indicated a significant protective effect of ACE 2350A compared with 2350G among Muslims from the Arab Gulf and Pakistan (OR = 0.55; 95% CI, 0.42—0.71; p < .00001). No publication biases were observed.

Conclusions: Our results demonstrate that the ACE 2350A allele is associated with a significantly reduced hypertension risk among Muslims from the Arab Gulf and Pakistan, yet an elevated risk among Han Chinese.

Angiotensin-Converting Enzyme Gene 2350 G/A Polymorphism Is Associated with Left Ventricular Hypertrophy but Not Essential Hypertension

The angiotensin-converting enzyme (ACE) gene (ACE) is one of the most studied candidate genes related to essential hypertension (EH) and left ventricular hypertrophy (LVH). ACE rs4343 synonymous coding polymorphism (2350 G/A) is known among the polymorphisms of this gene to have the most significant effect on plasma ACE concentrations. The aim of the present study was to investigate the association of this polymorphism with EH and LVH in 440 subjects (246 EH patients and 194 controls) from a Chinese Han population. In this study, 2350 G/A genotypes were identified by polymerase chain reaction and restriction digestion in all study participants, and left ventricular mass was assessed by 2-mode echocardiography in 178 untreated EH patients. There was no significant difference in either genotype distribution (p=0.3659) or allele frequency (p=0.1453) between EH and control groups. In addition, the 2350 G/A polymorphism had no effect on blood pressure in either controls or untreated EH patients. The distribution of genotypes differed significantly when patients with LVH were examined, i.e., 14.71% GG, 54.41% GA, and 30.88% AA patients had this complication, and 36.36% GG, 42.73% GA, and 20.91% AA patients did not (p=0.0070). The LVH patients had a higher A allele frequency (58.09%) than patients without LVH (42.27%) (p=0.0037). Logistic regression analysis revealed that the association between the A allele and LVH was independent of age, blood pressure, and body mass index. The relative risk of LVH in patients bearing the A allele (GA+AA group) compared with that of GG hypertensive patients was 3.31 (95% confidence interval [CI]: 1.43 to 7.68). These findings suggest an association between LVH and the 2350A allele in hypertensive patients.

Association of Angiotensin Converting Enzyme Gene Polymorphisms with Left Ventricular Hypertrophy

The angiotensin converting enzyme gene (ACE) is of much interest as a candidate gene conferring an individual's genetic susceptibility to left ventricular hypertrophy (LVH). LVH has long been thought to be an end point of essential hypertension (EH), rather than a separate entity, though it is influenced by a unique set of hormonal, vascular and genetic factors. In this study, we attempted to determine whether two representative polymorphisms of the ACE gene, ACE I/D and 2350 G>A, known to be associated with EH and to have a highly significant influence on plasma ACE levels, could implicate ACE as a quantitative trait locus (QTL) for LVH. We carried out a retrospective, case-control study of the two ACE polymorphisms amongst 180 nationals (50 LVH patients and 130 controls) from the United Arab Emirates (Emirati)--an ethnic group characterized by an absence of alcohol intake and cigarette smoking--for putative correlations with LVH. Clinical diagnoses of LVH were based on echocardiographic and ECG criteria. ACE I/D and 2350 G>A genotypes were determined by polymerase chain reaction (PCR) and restriction digestion. Univariate and multivariate logistic regression analyses revealed an association between ACE polymorphisms and LVH. Haplotype analysis further supported this finding. The ACE I/D and ACE 2350 G>A polymorphisms were in strong linkage disequilibrium and were independently associated with LVH, suggesting that ACE is likely to be a QTL for LVH. In conclusion, This is the first association study of the ACE 2350 G>A polymorphism with LVH; the results showed that this polymorphism, along with ACE I/D, is associated with LVH.

Pathomechanisms and the diagnosis of arterial hypertension in pediatric renal allograft recipients

Arterial hypertension is common in pediatric renal allograft recipients. While the causes are multifactorial, including chronic graft rejection, immunosuppressive therapy, and renal vascular disorders, the effect of hypertension on renal allograft function is detrimental. As in adults, if not treated early and aggressively, hypertension may lead to cardiovascular damage and graft failure. Pathophysiological changes in the arteries and kidney af-ter renal transplantation and the impact of receptor regulation have not been studied extensively in children. For identifying children with hypertension following renal transplantation casual blood pressure measurements do not accurately reflect average arterial blood pressure and circadian blood pressure rhythm. Ambulatory 24-h blood pressure monitoring should regularly be applied in trans-plant patients. The purpose of this review is to analyze pathophysiological aspects of risk factors for arterial hypertension and underline the importance of regular blood pressure monitoring and early therapeutic intervention.

Risk factors for heart failure

Despite remarkable therapeutic advances in the management of patients with heart failure (HF), the mortality due to this syndrome remains high. Identifying free-living individuals who are at high risk for developing HF may allow implementing strategies that can prevent HF. Prospective epidemiologic studies have identified several risk factors and risk markers for HF. This article reviews current knowledge regarding conventional and newer risk markers for HF, outlines possible underlying mechanisms for the increased HF risk, and provides a framework for clinical multivariate risk prediction using HF risk factors.