The association between circulating angiotensin-converting enzyme and cardiovascular risk in the elderly: a cross-sectional study

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.

Live to die another day: novel insights may explain the pathophysiology behind smoker's paradox in SARS-CoV-2 infection

The severe acute respiratory coronavirus 2 (SARS-CoV-2) infection demonstrates a highly variable and unpredictable course. Several reports have claimed a smoker's paradox in coronavirus disease 2019 (COVID-19), in line with previous suggestions that smoking is associated with better survival after acute myocardial infarction and appears protective in preeclampsia. Several plausible physiological explanations exist accounting for the paradoxical observation of smoking engendering protection against SARS-CoV-2 infection. In this review, we delineate novel mechanisms whereby smoking habits and smokers' genetic polymorphism status affecting various nitric oxide (NO) pathways (endothelial NO synthase, cytochrome P450 (CYP450), erythropoietin receptor (EPOR); β-common receptor (βcR)), along with tobacco smoke modulation of microRNA-155 and aryl-hydrocarbon receptor (AHR) effects, may be important determinators of SARS-CoV-2 infection and COVID-19 course. While transient NO bioavailability increase and beneficial immunoregulatory modulations through the above-mentioned pathways using exogenous, endogenous, genetic and/or therapeutic modalities may have direct and specific, viricidal SARS-CoV-2 effects, employing tobacco smoke inhalation to achieve protection equals self-harm. Tobacco smoking remains the leading cause of death, illness, and impoverishment.

The effect of angiotensin-converting enzyme levels on COVID-19 susceptibility and severity: a Mendelian randomization study

Background

There has been uncertainty about the safety or benefit of angiotensin-converting enzyme (ACE) inhibitors during the COVID-19 pandemic. We used Mendelian randomization using genetic determinants of serum-ACE levels to test whether decreased ACE levels increase susceptibility to SARS-CoV-2 infection or COVID-19 severity, while reducing potential bias from confounding and reverse causation in observational studies.

Methods

Genetic variants strongly associated with ACE levels, which were nearby the ACE gene, were identified from the ORIGIN trial and a separate genome-wide association study (GWAS) of ACE levels from the AGES cohort. The ORIGIN trial included 4147 individuals of European and Latino ancestries. Sensitivity analyses were performed using a study of 3200 Icelanders. Cohorts from the COVID-19 Host Genetics Initiative GWAS of up to 960 186 individuals of European ancestry were used for COVID-19 susceptibility, hospitalization and severe-disease outcome.

Results

Genetic variants were identified that explain between 18% and 37% of variance in ACE levels. Using genetic variants from the ORIGIN trial, a standard-deviation decrease in ACE levels was not associated with an increase in COVID-19 susceptibility [odds ratio (OR): 1.02, 95% confidence interval (CI): 0.90, 1.15], hospitalization (OR: 0.86, 95% CI: 0.68, 1.08) or severe disease (OR: 0.74, 95% CI: 0.51, 1.06). Using genetic variants from the AGES cohort, the result was similar for susceptibility (OR: 0.98, 95% CI: 0.89, 1.09), hospitalization (OR: 0.86, 95% CI: 0.66, 1.11) and severity (OR: 0.75, 95% CI: 0.50, 1.14). Multiple-sensitivity analyses led to similar results.

Conclusion

Genetically decreased serum ACE levels were not associated with susceptibility to, or severity of, COVID-19 disease. These data suggest that individuals taking ACE inhibitors should not discontinue therapy during the COVID-19 pandemic.

Role of Angiotensin-Converting Enzyme (ACE) gene polymorphism and ACE activity in predicting outcome after acute myocardial infarction

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The role of ACE gene polymorphism and its influence on ischemic heart disease and acute coronary syndrome are studied in last so many years without any concrete conclusion.

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In this study we investigated role of ACE gene polymorphism and Ace activity in large number of study population.

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The ACE (I/D) polymorphism showed no association with development of acute STEMI. Neither ACE I/D polymorphism nor ACE activity predicted in-hospital mortality in patients admitted with acute STEMI.

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Hence knowledge of ACE polymorphism and Ace activity is not useful in predicting STEMI or mortality after STEMI.

Background

The Ace polymorphism had shown association with ACE activity, premature atherosclerosis, myocardial infarction, LV dysfunction, LV remodelling, severity and extent of CAD and mortality after MI. Though ACE I/D polymorphism has been reported to be associated with various cardiovascular diseases it remained a controversial risk factor and studies have presented conflicting results. This study was designed to determine the association between ACE) gene insertion/deletion (I/D) polymorphism, ACE activity and acute STEMI in Indian population and to determine its influence on outcome after acute MI.

Materials and methods

We investigated 934 patients diagnosed with acute STEMI who underwent thrombolysis. ACE I/D polymorphism was detected by polymerase chain reaction and ACE activity was measured in 615 patients.

Results

The prevalence of DD, ID, and II genotypes in our study group were 41.97%, 34.36%, and 23.66% respectively. The ACE polymorphism was not significantly associated with the type of myocardial infarction, the LV ejection fraction, the number of vessels diseased and patency of the vessel after thrombolysis. The polymorphism had no influence on in hospital mortality (P = 0.453). The ACE activity also showed no influence on in hospital mortality (P = 0.482). The age > 60 years, Male gender, occluded artery and severe LV dysfunction (LVEF < 35%) were predictors of in-hospital mortality on multivariate regression analysis.

Conclusion

There was no differences among ACE (I/D) polymorphism observed in STEMI population. Neither ACE I/D polymorphism nor ACE activity predicted in-hospital mortality inpatients admitted with acute STEMI.

Association between the ACE-I/D polymorphism and nicotine dependence amongst patients with lung cancer

The biologically active peptide angiotensin II is cleaved from angiotensinogen by the renin and the angiotensin-converting enzyme (ACE), an enzymatic cascade known as the renin-angiotensin system (RAS). RAS may be important in the etiology of nicotine dependence by influencing dopaminergic signaling. In the present study, the association between an insertion/deletion (I/D) polymorphism of ACE and nicotine dependence amongst patients with lung cancer was assessed. To date, several studies have shown the relevance of this polymorphic variant in both nicotine dependence and lung cancer. However, the present study is the first to address the potential role of the ACE-I/D polymorphism in nicotine dependence among patients with lung cancer. Genotyping was performed in 305 patients with lung cancer (males/females, 214/91). Significantly more male smokers had the ACE-I allele compared with male non-smokers (44.9 vs. 20.0%; P<0.05). The risk of smoking was ~5-fold higher for males with the ACE-I allele (ACE-II homozygous and ACE-ID heterozygous) vs. ACE-DD homozygous (odds ratio, 5.47; 95% confidence interval, 1.4-21.9; P=0.016). The pack-year smoking history in a subgroup of females with squamous cell carcinoma carrying the ACE-I allele was significantly lower compared with ACE-DD (37.1±14.1 vs. 57.0±29.1; F=4.5; P=0.046). The ACE-I/D polymorphism accounted for 17.6% of the smoking severity in this patient group (β, -0.42; multiple R² change, 0.176; P=0.046). These results suggest that the ACE-I/D polymorphism contributes to the risk of nicotine dependence and smoking severity in lung cancer patients in a sex-specific manner.

Gender difference and genetic variance in lipoprotein receptor-related protein 1 is associated with mortality

Cardiovascular diseases are an important health resource problem and studies have shown a genetic association between single nucleotide polymorphisms (SNPs) and cardiovascular diseases. According to the literature, lipoprotein receptor-related protein 1 (LRP1) is associated with coronary artery disease. The aim of the present study was to evaluate a possible association between different genotypes of LRP1 and all-cause and cardiovascular mortality from a gender perspective. In the present study, 489 elderly community-living people were invited to participate. Clinical examination, echocardiography and blood sampling including SNP analyses of LRP1 (rs1466535) were performed, including the T/T, C/T and C/C genotypes, and the participants were followed for 6.7 years. During the follow-up period, 116 (24%) all-cause and 75 (15%) cardiovascular deaths were registered. In the female population, the LRP1 of the T/T or C/T genotype exhibited a 5.6-fold increased risk of cardiovascular mortality and a 2.8-fold increased risk of all-cause mortality compared with the C/C genotype. No such genotype differences could be seen in the male population. Gender differences could be seen regarding the risk of mortality in the different genotypes. Females with the LRP1 T/T or C/T genotypes exhibited a significantly increased risk of both all-cause and cardiovascular mortality compared with the C/C genotypes. Therefore, more individualized cardiovascular prevention and treatment should be prioritized. However, since this was a small study, the observations should only be regarded as hypothesis-generating.

High-Saturated-Fat Diet Increases Circulating Angiotensin-Converting Enzyme, Which Is Enhanced by the rs4343 Polymorphism Defining Persons at Risk of Nutrient-Dependent Increases of Blood Pressure

BACKGROUND

Angiotensin-converting enzyme (ACE) plays a major role in blood pressure regulation and cardiovascular homeostasis. Contrary to the assumption that ACE levels are stable, circulating ACE has been shown to be altered in obesity and weight loss. We sought to examine effects of a high-saturated-fat (HF) diet on ACE within the NUtriGenomic Analysis in Twins (NUGAT) study.

METHODS AND RESULTS

Forty-six healthy and nonobese twin pairs initially consumed a carbohydrate-rich, low-fat diet over a period of 6 weeks to standardize for nutritional behavior prior to the study, followed by 6 weeks of HF diet under isocaloric conditions. After 6 weeks of HF diet, circulating ACE concentrations increased by 15% (P=1.6×10^-30), accompanied by an increased ACE gene expression in adipose tissue (P=3.8×10^-6). Stratification by ACE rs4343, a proxy for the ACE insertion/deletion polymorphism (I/D), revealed that homozygous carriers (GG) of the variant had higher baseline ACE concentrations (P=7.5×10^-8) and additionally showed a 2-fold increase in ACE concentrations in response to the HF diet as compared to non- or heterozygous carriers (AA/AG, P=2×10^-6). GG carriers also responded with higher systolic blood pressure as compared to AA/AG carriers (P=0.008). The strong gene-diet interaction was confirmed in a second independent, cross-sectional cohort, the Metabolic Syndrome Berlin Potsdam (MeSyBePo) study.

CONCLUSIONS

The HF-diet-induced increase of ACE serum concentrations reveals ACE to be a potential molecular link between dietary fat intake and hypertension and cardiovascular disease (CVD). The GG genotype of the ACE rs4343 polymorphism represents a robust nutrigenetic marker for an unfavorable response to high-saturated-fat diets.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01631123.

PDGF-D gene polymorphism is associated with increased cardiovascular mortality in elderly men

Background

Platelet-derived growth factor (PDGF) D has been reported to be active in fibroblasts, and in areas of myocardial infarction. In this longitudinal study we evaluated the association between PDGF-D polymorphism and cardiovascular mortality, and attempted to discover whether specific genotype differences regarding risk could be observed, and if gender differences could be seen.

Methods

Four hundred seventy-six elderly community participants were included in this study. All participants underwent a clinical examination, echocardiography, and blood sampling including PDGF-D single nucleotide polymorphism (SNP) analyses of the rs974819 A/A, G/A and G/G SNP. The follow-up time was 6.7 years.

Results

No specific genotype of rs974819 demonstrated increased cardiovascular mortality in the total population, however, the male group with genotypes A/A and G/A demonstrated an increased risk that persisted in a multivariate evaluation where adjustments were made for well-known cardiovascular risk factors (2.7 fold compared with the G/G genotype). No corresponding finding was observed in the female group.

Conclusion

We report here for the first time that the genotypes G/A or A/A of the SNP rs974819 near PDGF-D exhibited a 2.7 fold increased cardiovascular mortality risk in males. Corresponding increased risk could not be observed in either the total population and thus not in the female group. However, the sample size is was small and the results should be regarded as hypothesis-generating, and thus more research in the field is recommended.

Implications of ACE (I/D) Gene Variants to the Genetic Susceptibility of Coronary Artery Disease in Asian Indians

Angiotensin-1-converting enzyme (ACE) gene has established substantial attention in the recent years as a candidate gene for hypertension, cardiovascular diseases and type 2 diabetes. The aim of the present study was to investigate the association of ACE (I/D) polymorphism with coronary artery disease (CAD) in a north Indian population. A total of 662 subjects (330 CAD patients and 332 healthy controls) were examined for association of ACE gene (I/D) polymorphism and environmental risk factors. The mean age of the CAD patients and control subjects was 60.53 ± 8.6 years and 56.55 ± 7.7 years, respectively (p = 0.000). Anthropometric and demographic data showed BMI values significantly higher among CAD patients and control subjects (26.98 ± 4.9 vs 24.04 ± 4.7, p = 0.000). We observed pronounced central obesity in both CAD patients and controls, even at the lowest BMI values (<23 kg/m²). Dyslipidemia was highly prevalent in CAD patients compared to control subjects. Genotypic data showed significantly higher frequency of DD genotype in CAD patients than that of control subjects (40 vs 28.3 %). No significant difference was observed in the distribution of ID genotypes between CAD patients and control subjects. Logistic regression analysis of data demonstrate that DD genotype was associated with 1.8 fold increased risk of development of CAD in Asian Indians (OR 1.8; 95 % CI 1.22-2.66; p = 0.003). The frequency of D allele was significantly higher in CAD patients (p = 0.001). No significant difference was observed in the clinical and biochemical characteristics of CAD patients and controls when the data was stratified according to the genotypes of ACE gene. In conclusion, DD genotype of ACE gene may be associated with increased risk of CAD in Asian Indian population.

Insertion/Insertion Genotype of Angiotensin I-Converting-Enzyme Gene Predicts Risk of Myocardial Infarction in North East India

Myocardial infarction (MI) is common in India and the disease occurs at a relatively younger age. We wanted to look for association of Angiotensin I-converting enzyme (ACE) gene with MI in North East India. We also wanted to examine possible environmental interaction of ACE gene with established cardiovascular risk factors in causation of MI. In the study carried out in Assam Medical College, 200 consecutive confirmed cases of MI were recruited. Equal numbers of age- and sex-matched control subjects from hospital workers and patients attending the hospital for diseases unrelated to cardiovascular disease were enrolled. Structured questionnaires were used to note demographic and clinical factors. Cardiovascular risk factors were determined from history, physical examination and biochemical investigations. ACE insertion/deletion (I/D) polymorphism was determined by PCR method. Interaction of ACE gene with other risk factors was noted. The study identified ACE II genotype (odds ratio = 3.02; 95% CI 1.40-6.51), smoking, hypertension, diabetes and serum triglyceride > 150 mg/dl as independent risk factors for MI. ACE II genotype showed greater risk in non-smokers, non-hypertensives, non-diabetics and in subjects with LDL-C < 130 mg/dl. Low HDL cholesterol enhanced the genetic risk. Subjects with ACE II genotype have an independent risk of developing MI, specially in low cardiovascular risk subjects.

Methodological Comparisons of Heart Rate Variability Analysis in Patients With Type 2 Diabetes and Angiotensin Converting Enzyme Polymorphism

Angiotensin converting enzyme (ACE) polymorphism has been shown to be important in hypertension progression and also in diabetes complications, especially associated with heart disease. Heart rate variability (HRV) is an established measure for classification of autonomic function regulating heart rate, based on the interbeat interval time series derived from a raw ECG recording. Results of this paper show that the length (number of interbeat intervals) and preprocessing of the tachogram affect the HRV analysis outcome. The comparison was based on tachogram lengths of 250, 300, 350, and 400 RR-intervals and five preprocessing approaches. An automated adaptive preprocessing method for the heart rate biosignal and tachogram length of 400 interbeat intervals provided the best classification. HRV results differed for the Type 2 Diabetes Mellitus (T2DM) group between the I/I genotype and the I/D and D/D genotypes, whereas for controls there was no significant difference in HRV between genotypes. Selecting an appropriate length of recording and automated preprocessing has confirmed that there is an effect of ACE polymorphism including the I/I genotype and that I/I should not be combined with I/D genotype in determining the extent of autonomic modulation of the heart rate.

Effect of buttermilk consumption on blood pressure in moderately hypercholesterolemic men and women

OBJECTIVES

Milk fat globule membrane (MFGM) found in buttermilk is rich in unique bioactive proteins. Several studies suggest that MFGM proteins possess biological activities such as cholesterol-lowering, antiviral, antibacterial, and anticancer properties, but data in humans are lacking. Furthermore, to our knowledge, no study has yet investigated the antihypertensive potential of MFGM proteins from buttermilk. The aim of this study was to investigate the effects of buttermilk consumption on blood pressure and on markers of the renin-angiotensin-aldosterone (RAS) system in humans.

METHODS

Men and women (N = 34) with plasma low-density lipoprotein cholesterol < 5 mmol/L and normal blood pressure (< 140 mm Hg) were recruited in this randomized, double-blind, placebo-controlled, crossover study. Their diets were supplemented with 45 g/d of buttermilk and with 45 g/d of a macro-/micronutrient-matched placebo in random order (4 wk for each diet).

RESULTS

Buttermilk consumption significantly reduced systolic blood pressure (-2.6 mm Hg; P = 0.009), mean arterial blood pressure (-1.7 mm Hg; P = 0.015), and plasma levels of the angiotensin I-converting enzyme (-10.9%; P = 0.003) compared with the placebo, but had no effect on plasma concentrations of angiotensin II and aldosterone.

CONCLUSION

Short-term buttermilk consumption reduces blood pressure in normotensive individuals.

Associations of ACE gene insertion/deletion polymorphism, ACE activity, and ACE mRNA expression with hypertension in a Chinese population

Background

The present study was designed to explore the association of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D, rs4646994) polymorphism, plasma ACE activity, and circulating ACE mRNA expression with essential hypertension (EH) in a Chinese population. In addition, a new detection method for circulating ACE mRNA expression was explored.

Methods

The research was approved by the ethics committee of Zhejiang Provincial Center for Disease Prevention and Control. Written informed consent was obtained prior to the investigation. 221 hypertensives (cases) and 221 normotensives (controls) were interviewed, subjected to a physical examination, and provided blood for biochemical and genetic tests. The ACE mRNA expression was analyzed by real time fluorescent quantitative Reverse Transcription PCR (FQ-RT-PCR). We performed logistic regression to assess associations of ACE I/D genotypes, ACE activity, and ACE mRNA expression levels with hypertension.

Results

The results of the multivariate logistic regression analysis showed that the additive model (ID, DD versus II) of the ACE genotype revealed an association with hypertension with adjusted OR of 1.43(95% CI: 1.04-1.97), and ACE ID genotype with adjusted OR of 1.72(95% CI: 1.01-2.92), DD genotype with adjusted OR of 1.94(95% CI: 1.01-3.73), respectively. In addition, our data also indicate that plasma ACE activity (adjusted OR was 1.13(95% CI: 1.08-1.18)) was significantly related to hypertension. However, the plasma ACE mRNA expressions were not different between the cases and controls.

Conclusion

ACE I/D polymorphism and ACE activity revealed significant influence on hypertension, while circulating ACE mRNA expression was not important factors associated with hypertension in this Chinese population. The detection of circulating ACE mRNA expression by FQ-RT-PCR might be a useful method for early screening and monitoring of EH.

Associations of genetic polymorphisms in the renin-angiotensin system with central aortic and ambulatory blood pressure in type 2 diabetic patients

Patients with type 2 diabetes (T2D) are at high risk of developing hypertension and related cardiovascular disease. The renin-angiotensin system (RAS) plays a central role in regulation of blood pressure (BP). Accordingly, each component of this system represents a potential candidate in the etiology of hypertension. This study investigated the impact of polymorphisms within the RAS on ambulatory and central BP in T2D subjects. A cohort of 761 subjects (55-65 years) with T2D was studied. Ambulatory and central BP were measured, and ACE I/D genotype, angiotensinogen M235T, renin rs6693954 and ATR1-A1166C polymorphisms were analyzed. Women carrying the AA-genotype had lower 24-hour and day-time systolic and diastolic BP (p<0.05), and lower night-time and central diastolic BP (p<0.05), compared to T allele carriers. In men, the AA-genotype was instead associated with higher central diastolic BP (p=0.018) and higher augmentation index (p=0.016). Further, the associations between the renin rs6693954 SNP and diastolic BP were strongly gender dependent (p≤0.001). In T2D patients, there is a gender-dependent association of the renin rs6693954 SNP with central and ambulatory BP. Women carrying the renin rs6693954 AA-genotype may be protected against the higher BP seen in men with the same genotype.

Impaired abdominal aortic wall integrity in elderly men carrying the angiotensin-converting enzyme D allele

OBJECTIVE

A polymorphism in the angiotensin-converting-enzyme gene (ACE I/D) has been associated with abdominal aortic aneurysm and a link between aortic aneurysm and aortic stiffness has been suggested. This study aimed to explore the links between ACE I/D polymorphism, circulating ACE and abdominal aortic wall integrity as reflected by abdominal aortic wall stiffness.

MATERIAL

A total of 212 men and 194 women, aged 70-88 years, were studied.

METHODS

Mechanical properties of the abdominal aorta were determined using the Wall Track System, ACE genotype using the polymerase chain reaction (PCR) and circulating ACE level by enzyme-linked immunosorbent assay (ELISA).

RESULTS

In men, pulsatile diameter change differed between genotypes (II 0.70, ID 0.55 and DD 0.60 mm, P = 0.048), whereas a tendency was seen for distensibility coefficient (DC) (II 10.38, ID 7.68 and ID 8.79, P = 0.058). Using a dominant model (II vs. ID/DD), men carrying the ACE D allele had lower pulsatile diameter change (P = 0.014) and DC (P = 0.017) than II carriers. Multiple regression analyses showed additional associations between the D allele and increased stiffness β, and reduced compliance coefficient.

CONCLUSION

Men carrying the ACE D allele have stiffer abdominal aortas compared with II carriers. Deranged abdominal aortic stiffness indicates impaired vessel wall integrity, which, along with other local predisposing factors, may be important in aneurysmal disease.