Insertion/deletion polymorphism of the angiotensin I-converting enzyme gene in patients with hypertension, non-insulin-dependent diabetes mellitus, and coronary heart disease in Taiwan

Effects of Acute Aquatic High-Intensity Intermittent Exercise on Blood Pressure and Arterial Stiffness in Postmenopausal Women with Different ACE Genotypes

The present study investigated the effects of acute aquatic high-intensity intermittent jumping (HIIJ) on blood pressure (BP) and arterial stiffness in postmenopausal women with different angiotensin-converting enzyme genotypes (ACE). We recruited 12 postmenopausal women carrying the ACE deletion/deletion (DD) genotype and 61 carrying the insertion/insertion or insertion/deletion (II/ID) genotype. The participants performed 12 trials of 30 s, 75% heart rate reserve (HRR) jumping, and 60 s, 50% HRR recovery, and 3 trials of 40 s upper limb resistance exercises were performed as fast as possible. The heart rate (HR) and BP were measured before exercise, immediately, 10 min, and 45 min after exercise. The brachial-ankle pulse wave velocity (baPWV) was measured before and after exercise. The systolic blood pressure (SBP) of the DD genotype increased more significantly than those with the II/ID genotype post-exercise (30.8 ± 4.48 vs. 20.4 ± 2.00 mmHg, p = 0.038). The left and right sides of baPWV increased significantly after exercise (1444.8 ± 29.54 vs. 1473.4 ± 32.36 cm/s, p = 0.020; 1442.1 ± 30.34 vs. 1472.0 ± 33.09, p = 0.011), and there was no significant difference between the two groups. The HIIJ increased baPWV. The postmenopausal women with the DD genotype have a higher SBP increased post-exercise than those with II/ID genotype. These findings suggest that the aquatic exercise program has better effects in decreasing blood pressure in postmenopausal women with the II/ID genotype. Those with the DD genotype should pay attention to the risk of increasing blood pressure after aquatic HIIJ exercise.

Association Between Polymorphism of the Angiotensin I Converting Enzyme Gene and Hypertension in Turkish Type II Diabetic Patients

It has been suggested that an insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin converting enzyme (ACE) gene may be associated with essential hypertension. The aim of this study was to examine the association between ACE I/D polymorphism with blood pressure level and hypertension status in Turkish type 2 diabetic subjects. Hundred and seven hypertensive (78 female, 29 male) and 132 normotensive type 2 diabetic subjects (73 female, 59 male) and 138 sex and age matched control subjects (87 female, 51 male) without diabetes and hypertension were included into the study. The I/D polymorphism was determined by polymerase chain reaction (PCR). There were no statistically difference in genotypic and allelic frequencies of the ACE I/D polymorphism between the hypertensive and normotensive diabetic patients and control subjects. Also no significant differences was detected in systolic and diastolic blood pressure among three different genotypes. ACE I/D polymorphism does not seem to play an important role in the development of hypertension in Turkish type 2 diabetic subjects, but prospective studies may show an association between ACE gene polymorphism and the development of hypertension in diabetic subjects.

Relationship between angiotensin-converting enzyme gene insertion/deletion polymorphism, angiographically defined coronary artery disease and myocardial infarction in patients with type 2 diabetes mellitus

INTRODUCTION

The insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been implicated in the pathogenesis of cardiovascular diseases. The objective of the present study was to investigate the influence of ACE gene I/D polymorphism on the development and progression of coronary artery disease (CAD) and myocardial infarction (MI) in type 2 diabetic (T2DM) patients.

MATERIALS AND METHODS

We screened 283 T2DM patients, inclusive of 160 patients with angiographically defined CAD, 73 patients with MI, 89 patients without MI and 121 T2DM individuals with no evidence of CAD for ACE gene I /D polymorphism.

RESULTS

There was no significant difference in the distribution of genotypes and alleles of ACE gene I/D polymorphism between T2DM+CAD and T2DM (non-CAD) groups. However, a significant association of this polymorphism with MI in T2DM+CAD patients (p=0.024) was observed. Further analysis revealed that the frequencies of the DD and ID genotypes increased with the number of stenosed coronary vessels (p=0.026). The DD genotype and the D allele were more frequent in the subgroup of T2DM patients with multivessel CAD (p=0.01) than in individuals with single vessel stenosis.

CONCLUSIONS

These findings reveal a significant relationship between ACE gene I/D polymorphism, multivessel CAD and also the occurrence of MI in T2DM individuals with significant coronary stenoses in our population.

Meta-analysis of the association between the insertion/deletion polymorphism in ACE gene and coronary heart disease among the Chinese population

OBJECTIVE

Many studies have suggested that the angiotensin-converting enzyme (ACE) gene might be involved in the development of coronary heart disease (CHD). However, the results have been inconsistent. In this study, the authors performed a meta-analysis to assess the association between ACE I/D polymorphism and CHD susceptibility among the Chinese population.

METHODS

Published literature from PubMed, EMBASE, CNKI and Wan Fang Data was searched. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using a fixed or random-effects model.

RESULTS

Forty-six studies (5215 cases and 4782 controls) were identified. The results from the meta-analysis indicated statistically significant association between ACE I/D polymorphism and CHD risk under all three genetic models (co-dominant model DD vs. II: OR=2.40, 95% CI 2.02-2.84, DI vs. II: OR=1.19, 95% CI 1.05-1.34; dominant model: OR=1.51, 95% CI 1.33-1.70; recessive model: OR=2.14, 95% CI 1.86-2.45; multiplicative model: OR=1.57, 95% CI 1.43-1.72 ). Further sensitivity analysis confirmed the significant association.

CONCLUSIONS

The meta-analysis indicated a significant association between ACE I/D polymorphism and CHD susceptibility among the Chinese population. However, further studies with the consideration of gene-gene and gene-environment interactions should be conducted to investigate the association.

No association of angiotensin I converting enzyme I/D polymorphism with domain-specific cognitive function in aged men without dementia

Previous research studies have related the insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme (ACE) gene to cognitive function in various neuropsychiatric or neurodegenerative disorders, but not yet investigated its genetic association with specific cognitive domains. Thus, the aim of this study was to assess the possible association of the ACE I/D polymorphism with domain-specific cognitive function in normal cognitive aging. Four hundred and sixty-nine-aged ethnic Chinese men without dementia were enrolled for genotyping and evaluated using several neuropsychological tests [Mini-Mental Status Examination (MMSE), Digit Span Forward and Backward, and Cognitive Ability Screening Instrument Chinese language version (CASI C-2.0)]. No direct association was found between ACE genotypes and the MMSE, Digit Span tests, or CASI total scores. Although subjects with I/I genotype had the lowest cognitive performance in the CASI visual construction domain (P = 0.031), this statistical difference disappeared after correction for multiple comparisons. This study suggests that the ACE I/D polymorphism does not have any genetic association with global or specific cognitive domain in aged men without dementia.

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 polymorphism is associated with type 2 diabetes: a meta-analysis

The association of angiotensin-converting enzyme gene polymorphism with type 2 diabetes was investigated in many studies with conflicting results. To clarify this conflict, we performed a meta-analysis on recent previous reports on ACE gene polymorphism and its correlation to type 2 diabetes. A total of 15,166 subjects from 24 studies were included in this meta-analysis. Summary odds ratios (ORs) were estimated. Potential sources of heterogeneity and bias were explored. The D variant was associated with a 14% increased risk of T2D relative to the I variant (OR 1.14; 95% CI: 1.04-1.24). In subgroup analysis, Caucasian and East Asians showed significant association. No association was found in the Turkish groups. No publication bias was observed in this meta-analysis by using the Egger method (tau = 1.63, P = 0.12), as well as the Begg's test (z = 1.66, P = 0.10). Cumulative meta-analysis for the allelic contrast showed a trend of association as information accumulated. These data suggested that the variant of ACE I/D had a moderate positive association with type 2 diabetes.

Prevalence of the angiotensin I converting enzyme gene insertion/deletion polymorphism in a healthy Turkish population

Angiotensin converting enzyme (ACE) plays an essential role in the renin-angiotensin system. It converts angiotensin I to angiotensin II and inactivates bradykinin and tachykinins. Numerous studies have been published investigating associations of the ACE gene I/D polymorphism with various pathophysiological conditions. We examined the prevalence of the ACE I/D polymorphism in a sample of healthy volunteers from western Turkey, including 1063 healthy Turkish controls. Analysis of the ACE I/D gene polymorphisms by polymerase chain reaction found frequencies of 16.1% for the II genotype, 47.7% for the ID genotype, and 36.2% for the DD genotype. The allele frequency was 39.9% for the I alleles and 60.1% for the D allele. This study demonstrates that the allele and genotype frequency values for the Turkish population are similar to previously published frequencies for Caucasian populations.

Association of the insertion/deletion polymorphism of the angiotensin-converting enzyme gene with type 2 diabetes in two ethnic groups of Jerba Island in Tunisia

Introduction.The aim of the current study was to evaluate the role of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism on the prediction of type 2 diabetes in two ethnic populations from Jerba Island,Tunisia.

Methods. In this study, we analysed the genotypic and the allelic distributions of the ACE I/D polymorphism and conducted a case/control association study between healthy normoglycaemic controls and diabetic patients in the two studied groups.ACE gene polymorphism was analysed by polymerase chain reaction in 272 individuals consisting of 172 diabetic subjects and 100 controls.

Results.The genotype frequencies for DD, ID and II were 75.50%, 19.60% and 4.89% inArabs and 76.66%, 16.66% and 6.67% in Berbers, respectively, in the case group, and 42.85%, 35.71% and 21.43% inArabs and 57.50%, 22.50% and 20.00% in Berbers, respectively, in the control group.The DD frequency was significantly higher in the case group than in the control group (p<0.001), suggesting that the DD genotype is associated with an increased susceptibility to type 2 diabetes in our study populations.

Conclusions.The current investigation provides new evidence regarding the role of the ACE I/D polymorphism in the pathogenesis of type 2 diabetes in Jerbian populations. Furthermore, it underlines the importance of ethnicity, which should be considered in all studies aiming to test the genetic effects on the susceptibility to type 2 diabetes.

Frequency of angiotensin-converting enzyme gene polymorphism in Turkish type 2 diabetic patients

We aimed to investigate the angiotensin-converting enzyme (ACE) gene polymorphism, ACE activity and their associations with diabetic complications in Turkish patients with type 2 diabetes mellitus. A total of 143 patients and 133 controls were screened for ACE gene I/D polymorphism by using polymerase chain reaction. Serum ACE activities were determined spectrophotometrically. There was no significant difference in the distribution of ACE I/D genotypes between patients and controls. The patients with DD genotype had a higher ACE activity than those with ID and II. Hypertensive diabetic patients with DD genotype had higher ACE activities than those with ID and II. There was no significant difference in the distribution of ACE I/D genotypes between patients with and without nephropathy, retinopathy and hypertension except for patients with and without neuropathy. In patients with DD genotype, creatinine clearance correlated with duration of diabetes. The grade of retinopathy was correlated with duration of diabetes in DD and ID genotypes. The highest ACE activity was measured in hypertensive diabetics with DD genotype. ID genotype was suggested to be a risk factor and II was suggested to be protective for diabetic neuropathy. The DD and ID genotypes might be a predictor for the development of retinopathy in relation to duration of diabetes.

Genetics of human hypertension

Hypertension is a complex genetic disorder caused by interplay between several "risk" genes and environmental factors (genetic heritability approximately 30%). Most genetic studies of hypertension use a candidate gene approach and two conclusions have been made: there is no association or linkage with the genes studied, or the hypertension phenotype is heterogeneous and subgroups with hypertension related to certain polymorphisms cannot be identified because of background noise. Studies using intermediate phenotypes suggest the latter is most likely. Another problem is the reliability of gene structure assessment: usually only one or two gene polymorphisms are assessed. The use of intermediate phenotypes and dense mapping of candidate genes would provide a better approach for identifying genotype-phenotype correlations, which might enable the use of genotypes to identify more-specific therapeutic and preventative measures for hypertensives.

Lack of association between angiotensin-converting enzyme gene polymorphism and peripheral vascular disease in type 2 diabetic patients in Taiwan

A total of 361 Chinese patients with type 2 diabetes were studied for the association between peripheral vascular disease (PVD) and the insertion/deletion polymorphism involving a 287-bp alu repeat sequence at intron 16 of the angiotensin-converting enzyme (ACE) gene. The patients were divided into PVD (+) (n=45) and PVD (-) (n=316) based on an ankle-brachial index <0.9 and > or =0.9, respectively. Polymerase chain reaction was used to identify gene polymorphism. Results showed that D allele frequency in the patients without and with PVD was 31.8% and 33.3%, respectively (p=NS). The prevalence rates of II, ID and DD genotypes in the PVD (-) group were 45.6%, 45.3% and 9.2%, respectively; and the respective values for the PVD (+) group were 44.4%, 44.4% and 11.1% (p=NS). Prevalence rates of PVD in genotypes II, ID, and DD were 12.2%, 12.3% and 14.7%, respectively (p=NS). In logistic regression analyses, the unadjusted and adjusted odds ratios for DD vs II and ID vs II genotypes for PVD were not statistically significant. The respective adjusted odds ratios were 1.88 (0.56-6.29) and 1.33 (0.63-2.80). In conclusion, there was not a significant association between the ACE genotype and PVD in Chinese type 2 diabetic patients. However, a type 2 error can not be ruled out.

Association between genetic polymorphism of angiotensin-converting enzyme gene and Parkinson's disease

This study was designed to investigate the hypothesis that deletion/insertion (D/I) polymorphism of the angiotensin-converting enzyme (ACE) gene may contribute to increased risk of Parkinson's disease (PD). A case-control study was carried out to examine the association between the ACE genotype and the allele frequency in 127 sporadic PD patients compared with 198 healthy controls. The frequency of the homozygote DD genotype of the ACE gene was significantly increased in patients with PD than in the controls (chi(2)=6.09, p=0.048), despite that there was no significant difference in D/I allele frequency (chi(2)=2.25, p=0.133). Moreover, PD patients carrying the homozygote DD genotype were 1.13 times more frequent than subjects without the DD genotype (chi(2)=5.67, 95% CI=1.01-1.25, p=0.017). A stepwise logistic regression analysis of the presence of the DD genotype and data on risk factors for PD confirmed that the homozygote DD genotype was a modest independent risk factor for PD (OR=1.32, 95% CI=1.12-2.16). In addition, there was a trend of increasing number of DD genotype in older PD patients and the modest risk factor of DD genotype in PD was due to the significant difference of the DD homozygosity in old patients with onset age at or after 60 years. In conclusion, results of our study support the hypothesis that the ACE gene may indicate genetic susceptibility to PD, particularly in older individuals.

Insertion/deletion polymorphism of the ACE gene is associated with type 2 diabetes

In an attempt to examine the role of an ACE gene insertion/deletion (I/D) polymorphism in type 2 diabetes, we conducted a case-control association study among 132 couple-pairs from northern China. The genotype frequencies for II, ID, and DD were 39.8, 39.8, and 20.3%, respectively, in the case group and 44.8, 44.8, and 10.4% in the control group. The DD frequency was significantly higher in the case group than in the control group (chi(2)(1) = 4.77, P = 0.03), suggesting that the DD genotype is associated with an increased susceptibility to type 2 diabetes in our study population.

ACE insertion/deletion polymorphism and submaximal exercise hemodynamics in postmenopausal women

We sought to determine whether the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphism is associated with submaximal exercise cardiovascular hemodynamics. Postmenopausal healthy women (20 sedentary, 20 physically active, 22 endurance athletes) had cardiac output (acetylene rebreathing) measured during 40, 60, and 80% VO(2 max) exercise. The interaction of ACE genotype and habitual physical activity (PA) level was significantly associated with submaximal exercise systolic blood pressure, with only sedentary women exhibiting differences among genotypes. No significant effects of ACE genotype or its interaction with PA levels was observed for submaximal exercise diastolic blood pressure. ACE genotype was significantly associated with submaximal exercise heart rate (HR) with ACE II having approximately 10 beats/min higher HR than ACE ID/DD genotype women. ACE genotype did not interact significantly with habitual PA level to associate with submaximal exercise HR. ACE genotype was not independently, but was interactively with habitual PA levels, associated with differences in submaximal exercise cardiac output and stroke volume. For cardiac output, ACE II genotype women athletes had ~25% greater cardiac output than ACE DD genotype women athletes, whereas for stroke volume genotype-dependent differences were observed in both the physically active and athletic women. ACE genotype was not significantly associated, either independently or interactively with habitual PA levels, with submaximal exercise total peripheral resistance or arteriovenous O(2) difference. Thus the common ACE locus polymorphic variation is associated with many submaximal exercise cardiovascular hemodynamic responses.

Does age, sex, or ACE genotype affect glucose and insulin responses to strength training?

The purpose of the present study was to determine whether age, sex, or angiotensin I-converting enzyme (ACE) genotype influences the effects of strength training (ST) on glucose homeostasis. Nineteen sedentary young (age = 20-30 yr) men (n = 10) and women (n = 9) were studied and compared with 21 sedentary older (age = 65-75 yr) men (n = 12) and women (n = 9) before and after a 6-mo total body ST program. Fasting insulin concentrations were reduced in young men and in older men with ST (P < 0.05 in both). In addition, total insulin area under the curve decreased by 21% in young men (P < 0.05), and there was a trend for a decrease (11%) in older men (P = 0.06). No improvements in insulin responses were observed in young or older women. The ACE deletion/deletion genotype group had the lowest fasting insulin and insulin areas under the oral glucose tolerance test (OGTT) curve before training (all P < 0.05), but those with at least one insertion allele had a trend for a greater reduction in total insulin area than deletion homozygotes (P = 0.07). These results indicate that ST has a more favorable effect on insulin response to an OGTT in men than in women and offer some support for the hypothesis that ACE genotype may influence insulin responses to ST.

Renal perfusion and function in healthy African Americans

BACKGROUND

Despite their increased risk of nephropathy, remarkably little is known about renal perfusion and function in healthy African Americans.

METHODS

We enrolled 32 healthy African Americans and compared renal perfusion and function in 82 age-matched healthy Caucasians. Studies were performed on a diet containing 200 mmol of sodium and 100 mmol of potassium per day. In a separate study of 28 subjects, 10 African American and 18 Caucasians, the contribution of the renin-angiotensin system was assessed by measuring renal hemodynamic responses to angiotension II (Ang II) and captopril.

RESULTS

Although glomerular filtration rate (GFR) was similar, renal plasma flow (RPF) was significantly less in age-matched African Americans (568 +/- 18) than Caucasians (620 +/- 13 mL/min/1.73 m(2), P = 0.0063). After captopril, African Americans had a sevenfold greater vasodilator response and a rise in RPF (35.3 +/- 4.9 vs. 4.9 +/- 12.4 mL/min/1.73 m(2) in African Americans and Caucasians, respectively, P < 0.028). Ang II administration caused a significantly smaller vasoconstrictor response in African Americans (Ang II-induced fall in RPF, -97 +/- 18 vs. -150 +/- 9 mL/min/1.73 m(2), P = 0.05), and angiotensin-converting enzyme (ACE) inhibition enhanced the response to Ang II in African Americans significantly.

CONCLUSIONS

A reduction in RPF, blunting of the renal vascular response to Ang II, and an accentuated renal vasodilator response to captopril, which in turn corrects the blunting of responsiveness to Ang II, all suggest activation of the renin system in apparently healthy African Americans. As PRA was identical in Caucasians and African Americans, the findings suggest that it is the intrarenal-renin system that is activated in African Americans. This difference in normal control mechanisms could predispose to nephropathy.

Angiotensin-converting enzyme and cardiovascular disease risk

The published studies of the association of the angiotensin-converting enzyme (ACE) genotype with cardiovascular disease have used many different diagnostic criteria for cardiovascular disease and have drawn their samples from different patient groups and different populations. This review examines the association of the ACE DD genotype with cardiovascular disease risk in studies grouped by their case criterion, the geographical region of the population samples, and by the cardiovascular risk level of the patient sample. In studies where the underlying odds ratios are determined to be homogeneous, the overall odds ratios for myocardial infarction and coronary artery disease with regard to the ACE DD genotype are estimated using the Mantel-Haenszel method.

The D allele of the angiotensin-converting enzyme gene contributes towards blood LDL-cholesterol levels and the presence of hypertension

Coronary artery disease is a polygenic disease whose phenotypic manifestation depends on the interaction of the genetic background with a number of environmental factors. Recently, the gene coding for the angiotensin-converting enzyme (ACE) has been characterized and a deletion/insertion (D/I) polymorphism was defined. The prevalence of the three genotypes and their association with coronary artery disease (CAD) differ in different population groups. Mostly, the D allele was found as a significant risk factor for CAD, independently from other risk factors. In the present study, we determined the distribution of ACE alleles (D or I) in a cohort of healthy Israeli men and examined the correlation of the different genotypes with various CAD risk factors. We found LDL cholesterol levels to be highest in the DD genotype group, intermediate in the DI genotype group and lowest in the II genotype group. We also found higher blood pressure levels in subjects bearing the D allele compared to II homozygous subjects. In conclusion, it appears that the genetic influence of the D/I polymorphism on CAD manifests primarily through traditional risk factors.