Angiotensin-converting enzyme gene deletion polymorphism. A new risk factor for lacunar stroke but not carotid atheroma

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.

ROCK and PDE-5 Inhibitors for the Treatment of Dementia: Literature Review and Meta-Analysis

Dementia is a disease in which memory, thought, and behavior-related disorders progress gradually due to brain damage caused by injury or disease. It is mainly caused by Alzheimer’s disease or vascular dementia and several other risk factors, including genetic factors. It is difficult to treat as its incidence continues to increase worldwide. Many studies have been performed concerning the treatment of this condition. Rho-associated kinase (ROCK) and phosphodiesterase-5 (PDE-5) are attracting attention as pharmacological treatments to improve the symptoms. This review discusses how ROCK and PDE-5 affect Alzheimer’s disease, vascular restructuring, and exacerbation of neuroinflammation, and how their inhibition helps improve cognitive function. In addition, the results of the animal behavior analysis experiments utilizing the Morris water maze were compared through meta-analysis to analyze the effects of ROCK inhibitors and PDE-5 inhibitors on cognitive function. According to the selection criteria, 997 publications on ROCK and 1772 publications on PDE-5 were screened, and conclusions were drawn through meta-analysis. Both inhibitors showed good improvement in cognitive function tests, and what is expected of the synergy effect of the two drugs was confirmed in this review.

Neuroprotection in Stroke-Focus on the Renin-Angiotensin System: A Systematic Review

Stroke is the primary cause of disability in the adult population. Hypertension represents the leading risk factor being present in almost half the patients. The renin-angiotensin system is involved in the physiopathology of stroke and has an essential impact on hypertension as a risk factor. This article targeted the role of the renin-angiotensin system in stroke neuroprotection by reviewing the current literature available. The mechanism of action of the renin-angiotensin system was observed through the effects on AT1, AT2, and Mas receptors. The neuroprotective properties ascertained by angiotensin in stroke seem to be independent of the blood pressure reduction mechanism, and include neuroregeneration, angiogenesis, and increased neuronal resistance to hypoxia. The future relationship of stroke and the renin-angiotensin system is full of possibilities, as new agonist molecules emerge as potential candidates to restrict the impairment caused by stroke.

Association Between the Angiotensin-Converting Enzyme I/D Polymorphism and Risk of Cerebral Small Vessel Disease: A Meta-Analysis Based on 7186 Subjects

INTRODUCTION

Cerebral small vessel disease (CSVD) causes a quarter of all strokes and is the most common pathology underlying vascular dementia. However, the mechanism of CSVD remains unclear. Numerous studies have investigated whether the angiotensin-converting enzyme (ACE) intersection/deletion (I/D) polymorphism influences the risk of CSVD, but the results are controversial.

METHODS

We searched English and Chinese databases and calculated the odds ratio (OR) and 95% confidence interval (CI) to examine the existence of genetic associations between the ACE I/D polymorphism and the risk of CSVD. All relevant studies were screened and meta-analyzed using Review Manager 5.4.

RESULTS

A total of 27 studies involving 7,186 subjects were identified for the meta-analysis. The results of five genetic models showed a significantly increased risk of CSVD (allelic, OR=1.30; recessive, OR=1.41; dominant, OR=1.34; homozygous, OR=1.55 and heterozygous OR=1.22) in the overall analysis. Furthermore, in subgroup analysis, increased CSVD risks were also observed in Asian and Caucasian populations. We also found no relationship between ACE I/D and leukoaraiosis (LA) in patients with lacunar infarction (LI).

CONCLUSION

The ACE I/D polymorphism was positively associated with CSVD in both populations. However, this polymorphism did not increase the risk of LA in LI patients.

Pathophysiology of Lacunar Stroke: History's Mysteries and Modern Interpretations

Since the term "lacune" was adopted in the 1800s to describe infarctions from cerebral small vessels, their underlying pathophysiological basis remained obscure until the 1960s when Charles Miller Fisher performed several autopsy studies of stroke patients. He observed that the vessels displayed segmental arteriolar disorganization that was associated with vessel enlargement, hemorrhage, and fibrinoid deposition. He coined the term "lipohyalinosis" to describe the microvascular mechanism that engenders small subcortical infarcts in the absence of a compelling embolic source. Since Fisher's early descriptions of lipohyalinosis and lacunar stroke (LS), there have been many advancements in the understanding of this disease process. Herein, we review lipohyalinosis as it relates to modern concepts of cerebral small vessel disease (cSVD). We discuss clinical classifications of LS as well as radiographic definitions based on modern neuroimaging techniques. We provide a broad and comprehensive overview of LS pathophysiology both at the vessel and parenchymal levels. We also comment on the role of biomarkers, the possibility of systemic disease processes, and advancements in the genetics of cSVD. Lastly, we assess preclinical models that can aid in studying LS disease pathogenesis. Enhanced understanding of this highly prevalent disease will allow for the identification of novel therapeutic targets capable of mitigating disease sequelae.

ACE Gene in Egyptian Ischemic Stroke Patients

BACKGROUND

Angiotensin-1-converting enzyme (ACE) is a crucial player in vascular homeostasis and in the pathogenesis of atherosclerosis and hypertension. The present study was conducted to determine whether there is an association between the ACE insertion/deletion (I/D) polymorphism and ischemic stroke in Egyptian population. Also, we analyzed the ACE gene I/D polymorphism as a risk factor for small-vessel (SV) versus large-vessel (LV) disease.

METHODS

Sixty patients with ischemic stroke were included: 30 with SV disease and 30 with LV disease. In addition, a control group of 30 apparent healthy subjects were studied. Clinical assessment, computed tomography, magnetic resonance imaging brain, and genetic study using the polymerase chain reaction of ACE gene were done for all subjects.

RESULTS

We found that the distribution of ACE gene polymorphism frequency was significantly different between the 3 groups. The DD genotype was far more common in stroke patients compared to controls. It was also significantly more common in each of the patient groups compared to controls but rather similar in the 2 patient groups with SV and LV diseases.

CONCLUSION

We found that the ACE gene deletion/deletion genotype is common in Egyptian patients with non-cardioembolic ischemic stroke but does not appear to be specific neither to SV nor to LV disease.

Angiotensin converting enzyme (I/D) gene polymorphism contributes to ischemic stroke risk in Caucasian individuals: a meta-analysis based on 22 case-control studies

BACKGROUND

Stroke is a multifactorial disease in which genetic factors play an important role. Previous studies associated angiotensin converting enzyme (ACE) (insertion/deletion, I/D) gene polymorphism with ischemic stroke risk in Caucasian individuals reported conflicting results. The purpose of this study was to evaluate the association between ACE (I/D) gene polymorphism and ischemic stroke risk by a meta-analysis.

METHODS

The related studies were searched in MEDLINE, EMBASE and HuGEnet databases. The odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for ischemic stroke risk associated with this polymorphism were estimated using fixed-effect or random-effects model. Twenty-two studies (5528/5081 cases/controls) were eligible in our meta-analysis.

RESULTS

Overall, statistical associations of the ACE (I/D) polymorphism with ischemic stroke risk were found in dominant model (DD + ID versus II) : OR = 1.21, 95% CI = (1.06,1.38), P = 0.006, recessive model (DD versus ID + II): OR = 1.28, 95% CI = (1.05,1.55), P = 0.01, and homozygote comparison (DD versus II): OR = 1.37, 95% CI = (1.14,1.65), P = 0.001 for Caucasians. When stratifying according to stroke subtypes, there were similarly significant differences for small vessel disease in dominant model (DD + ID versus II) : OR = 1.44, 95% CI = (1.01,2.05), P = 0.04, recessive model (DD versus ID + II): OR = 1.30,95% CI = (1.09,1.55), P = 0.004, and homozygote comparison (DD versus II): OR = 1.44, 95% CI = (1.15,1.80), P = 0.001.

CONCLUSION

This analysis suggests that the ACE (I/D) polymorphism may be a risk factor for ischemic stroke, genotype DD of ACE could increase the risk of ischemic stroke in Caucasians. Subgroup analyses indicate that stroke subtypes may be a genetic risk factor of ischemic stroke, and there might be a greater genetic liability with small vessel disease.

ACE-II genotype and I allele predicts ischemic stroke among males in south India

Two hundred ischemic stroke patients and 193 age and sex matched healthy controls were studied for the presence of Angiotensin Converting Enzyme Insertion/Deletion (ACE I/D) gene polymorphism. The PCR studies revealed that ACE 'II' (OR = 2.055; p = 0.004) genotype and 'I' (OR = 1.411; p = 0.018) alleles were significantly associated with IS patients. Gender specific analysis revealed a strong association of 'II' (OR = 2.044; p = 0.014) genotype and 'I' (OR = 1.531; p = 0.011) allele with male sex. Classification of patients based on TOAST criteria, revealed a significant association for 'II' genotype (OR = 1.713; p = 0.043) and 'I' (OR = 1.382; p = 0.039) allele in LVD patients only. When the data was stratified based on age and sex, a statistically significant association was observed for ACE 'II' genotype (OR = 2.288; p = 0.006) and 'I' allele (OR = 1.395; p = 0.054) in IS male patients of > 50 years of age. The ACE 'D' allele was found to be increased in controls (OR = 0.709; p = 0.018) than IS patients. Multivariate logistic regression analysis showed that smoking and diabetes were the most powerful independent risk factor in LVD type of stroke. Thus, we presented here an evidence for a strong association of ACE 'II' genotype and 'I' allele compounded by factors such as smoking and diabetes among south Indian IS patients.

Angiotensin-converting enzyme gene polymorphism and middle cerebral artery stenosis in a Chinese Han population

The angiotensin-converting enzyme gene is a candidate gene of stroke. The present study involved 62 healthy volunteers and 148 patients with middle cerebral artery stenosis as confirmed by brain color ultrasound from a Han population in North China, and determined the peripheral blood angiotensin-converting enzyme genotype using PCR-restriction fragment length polymorphism analysis. The results showed that the frequencies of the DD genotype and D allele were increased in patients with middle cerebral artery stenosis, but the difference was not statistically significant compared with healthy controls. The findings of this study on the relationship between stroke genes and middle cerebral artery stenosis indicate no significant correlation between the frequencies of the DD genotype and D allele of angiotensin-converting enzyme and middle cerebral artery stenosis in this Han population from North China. In the future, studies will be carried out to investigate correlations between multiple stroke candidate gene synergy and middle cerebral artery stenosis to provide a foundation for the development of gene therapy.

Non-dipping and arterial hypertension depend on clinical factors rather than on genetic variability of ACE and RGS2 genes in patients with type 1 diabetes

The aim of our study was to characterize the association of clinical and genetic risk factors such as: ACE genotype (rs17997552, rs1800764, rs4459609) and RGS2 (rs2746071) with the development of hypertension (HT) and non-dipping phenomenon in patients with type 1 diabetes mellitus (T1DM). A total of 238 adolescents and young adults with T1DM-103 females and 135 males, aged 8-30 years (mean 17.35 ± 5.2) with diabetes duration 1-26 years (mean 7.72 ± 6.2), with mean HbA1c (IFCC) 58 ± 15 mmol/mmol-were subjected to 24-h ambulatory blood pressure measurements (ABPM). The results of the ABPM were analyzed in association with the polymorphisms of ACE and RGS2 genes and clinical data of patients. HT was recognized in 65 (27 %) and non-dipping in 111 (46.63 %) patients. In the multivariate analysis of factors predisposing to HT, the variables that remained significant were the following: male sex (OR 1.62; 95 % CI 1.171-2.250), non-dipping (OR 1.40; 95 % CI 1.03-1.90) and total cholesterol level (OR 1.01; 95 % CI 1.005-1.021). The only factor influencing non-dipping was the duration of diabetes-OR 1.09 (95 % CI 1.04-1.14). The patients displaying non-dipping have a twice increased risk of development of HT (OR 2.17; 95 % CI 1.21-3.89). There was no association between disturbances of blood pressure (BP) and genotypes of ACE: rs17997552, rs1800764, rs4459609 and RGS2: rs2746071. Clinical rather than genetic risk factors seem to be connected with BP disturbances in young patients with T1DM. Although we have identified representative groups of HT versus non-HT and dipping versus non-dipping subjects, the effect of genetic predisposition to the development of higher BP is too weak to be statistically significant.

Association between the ACE I/D polymorphism and risk of ischemic stroke: an updated meta-analysis of 47,026 subjects from 105 case-control studies

BACKGROUND

The association between the angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and risk of ischemic stroke (IS) remains controversial and ambiguous. To clarify this association, a large meta-analysis was performed.

METHODS

Electronic databases in both English and Chinese were used to identify relevant studies (updated in February 2014). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to describe the strength of the association.

RESULTS

One hundred and fifty eligible studies, including 18,258 IS cases and 28,768 controls, were identified. Meta-analysis of these studies pointed to a significant association between the ACE I/D polymorphism and IS risk: (D vs. I: OR=1.354, 95% CI=1.272-1.440, P<0.001; DD vs. II: OR=1.755, 95% CI=1.561-1.973, P<0.001; ID vs. II: OR=1.178, 95% CI=1.098-1.263, P<0.001; DD vs.

ID/II

OR=1.535, 95% CI=1.399-1.684, P<0.001; DD/ID vs. II: OR=1.353, 95% CI=1.251-1.463, P<0.001). Subgroup analysis revealed a significantly elevated risk among Asians, but with borderline statistical significance among Caucasians.

CONCLUSION

This meta-analysis indicated that the ACE I/D polymorphism may be a genetic susceptibility factor for IS, especially among Asians, but with borderline statistical significance for Caucasians. Further investigations are needed to validate our conclusions.

ACE polymorphism and use of ACE inhibitors: effects on memory performance

Memory is an important cognition function, being fundamental to the development and independence of individuals. Our aim was to investigate the influence apolipoprotein E (APOE) and angiotensin I-converting enzyme (ACE) polymorphism and ACE inhibitors use, besides their interaction on memory performance of healthy subjects over 50 years. The sample consisted of 205 subjects assessed for five types of episodic memory, using Wechsler Memory Scale-Revised (WMS-R), who answered a questionnaire about drug use and were assessed for the ACE insertion/deletion polymorphism and APOE polymorphism. We found no influence of the APOE gene. The use of ACE inhibitors beneficially influenced learning ability scores (p = 0.02). Besides, I allele carriers of ACE polymorphism showed higher verbal memory scores compared with homozygous DD. Also, we observed an interaction influencing learning ability between the ACE polymorphism and the use of inhibitors, the beneficial influence of the I allele was present only in individuals who make use of ACE inhibitors. We conclude that the ACE gene has influence on memory performance, and that this influence is modulated by ACE inhibitors use.

Angiotensin-converting enzyme gene insertion/deletion polymorphism and small vessel cerebral stroke in Indian population

Background. Hypertension is an established risk factor for small-vessel cerebral stroke and the renin-angiotensin system plays an important role in the maintenance of blood pressure. We aimed at evaluating the contribution of the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism to the risk of small-vessel stroke in south Indian population. Materials and Methods. We investigated 128 patients diagnosed with small-vessel stroke and 236 age, and gender-matched healthy controls. ACE I/D polymorphism was detected by polymerase chain reaction. Results. Hypertension was significantly more prevalent in the patient group and was associated with 6-fold increase in risk for stroke. ACE genotypes were in Hardy-Weinberg equilibrium in both patients and controls. Prevalence of DD, ID, and II genotypes in cases (34.4%, 43.7%, and 28%) did not differ significantly from controls (31.8%, 43.2%, and 25%). The polymorphism was not associated with small-vessel stroke (OR: 1.34; 95% CI: 0.52–1.55). However, diastolic blood pressure was associated with the ACE I/D genotypes in the patients. (DD; 90.2 ± 14.2> ID; 86.2 ± 11.9> II; 82.3 ± 7.8 mm Hg,  P = 0.047). Conclusion. Our study showed that hypertension, but not ACE I/D polymorphism, increased the risk of small-vessel stroke.

Endothelial Nitric Oxide Synthase and Angiotensin Converting Enzyme Gene Polymorphisms in Migraine Patients

INTRODUCTION

In this study, we investigated the association of migraine with the Variable Number of Tandem Repeats (VNTR), repeated as 27 base pair, gene polymorphism in intron 4 of the endothelial nitric oxide synthase (eNOS) and the insertion/deletion of angiotensin converting enzyme (ACE) gene polymorphisms.

METHODS

One hundred and five migraine and ninety seven healthy female control subjects were enrolled in the study. The patients were subdivided as migraine with aura and without aura, and the frequency and severity of migraine headaches were recorded. The eNOS VNTR (eNOS 4 a/b) and ACE insertion/deletion gene polymorphisms (ACE I/D) were assessed by polymerase chain reactions.

RESULT

The allele and genotype frequencies of eNOS 4 a/b gene polymorphism showed no difference between the migraine and control groups. The genotypic distribution of the ACE I/D gene polymorphism in the migraine group significantly differed from that in the control group. The DD and ID genotype increased the risk of migraine as much as 2.571 (95% CI-1.138-5.811) and 4.453 (95% CI-2.006-9.883) compared to the II genotype. The same increased risk sustained for both genotypes in the migraine with aura subgroup, but only the ID genotype remained as the risk factor in the migraine without aura subgroup (OR-3.750, 95% CI-1.493-9.420). No association of gene polymorphisms with migraine frequency and severity was observed.

CONCLUSION

Our findings support the relationship between migraine and the ACE I/D gene polymorphism. However, no association was found between migraine and the eNOS 4 a/b gene polymorphism.

Angiotensin converting enzyme and Alzheimer's disease

Alzheimer's disease (AD) is an incurable degenerative disease of the central nervous system, leading to dementia. The basis of AD is neurodegenerative process that leads to death of neurons in the cerebral cortex. This neurodegenerative process is associated with the formation of neurofibrillary tangles in the brain and the deposition of senile plaques, the main component of which is a beta-amyloid peptide (Ab). Risk factors for AD are age, as well as hypertension, atherosclerosis, diabetes and hypercholesterolemia in the pathogenesis of which involved angiotensin converting enzyme (ACE) – key enzyme of the renin-angiotensin (RAS) and kallikrein-kinin (KKS) systems. Recently it was discovered that ACE, along with other metallopeptidases, participates in the metabolism of Ab, cleaving the bonds at the N-terminal and C-terminal region of the molecule Ab. The role of the ACE in the degradation processes of Ab takes an interest. It is associated with the fact that the using of ACE inhibitors is the main therapeutic approach used in the treatment of various forms of hypertension and other cardiovascular diseases. However, until now not been resolved, can be used antihypertensive drugs that inhibit RAS for the treatment or prevention of AD. Currently, there are numerous studies on finding the relationship between RAS and AD.

Abnormal default-mode network in angiotensin converting enzyme D allele carriers with remitted geriatric depression

Using a cross-sectional case-control study of remitted geriatric depression (RGD), we characterised the relationships among cognitive function, whole-brain functional connectivity of the posterior cingulate cortex (PCC), and the angiotensin-converting enzyme (ACE) insertion or deletion (I/D) polymorphism during resting state. A total of 26 RGD patients and 24 matched controls were recruited, and neuropsychological tests, functional magnetic resonance imaging (fMRI) and ACE I/D genotype were examined for each subject. A 2 × 2 factorial analysis of variance (ANOVA) model (presence/absence of depression and presence/absence of ACE-D) was used to detect the interaction effect. Subsequent analyses were restricted to the significant interaction regions. There were significant interactions between disease and genotype at two clusters: left superior temporal gyrus/middle temporal gyrus and left cerebellum. And the ACE I/D polymorphism has disease-specific effects on the left superior temporal gyrus/middle temporal gyrus and cerebellum crus I. Furthermore, there was a significant positive correlation between the functional connection of PCC-left cerebellum crus I and the CFT-delayed recall test scores (r=0.668, P=0.003) in RGD group ACE-D allele carriers. These results suggest that the ACE I/D polymorphism can modulate the pathology of RGD, and the status of geriatric depression and the ACE-D allele may synergistically induce altered resting state network activity, which could influence the cognitive function and increase the mortality risk for cognitive impairment.

Genetics of ischemic stroke: where are we now?

As stroke is the third leading cause of death after heart failure and tumors worldwide, cerebrovascular diseases reached substantial attention. In the past few years, significant progression has been seen in identification of genetic variants in the background of stroke and other cerebrovascular and cardiovascular events. Examination of these variants is a new approach to recognize pathogenesis of disorders that hopefully helps in future prevention and prospects of screening and, optimistically, it contributes to special care of patients susceptible for stroke. In the background of ischemic stroke several genetic variants have been identified, which localize in genes encoding proteins involved in hemostasis, renin-angiotensin system and lipid metabolism. The number of these variants exponentially increases permanently due to rapid spreading of genome wide association studies. The goal of this review is to summarize the results of genetic studies on ischemic stroke. Here the authors focus on genetic variants which can have major role in personalized medicine and prevention of stroke. Orv. Hetil., 2011, 152, 455–463.

White matter hyperintensities in affected and unaffected late teenage and early adulthood offspring of bipolar parents: a two-center high-risk study

BACKGROUND

White matter hyperintensities (WMHs) are among the most replicated neuroimaging findings in bipolar disorder (BD). It is not clear whether these lesions are an artifact of comorbid conditions, or whether they are directly associated with the disorder, or even represent biological risk factor for BD.

METHODS

To test whether WMHs meet criteria for an endophenotype of BD, we conducted a high-risk design study and recruited 35 affected, 44 unaffected relatives of bipolar probands (age range 15-30 years), matched by age and sex with 49 healthy controls without any personal or family history of psychiatric disorders. The presence of WMHs was determined from Fluid Attenuated Inversion Recovery (FLAIR) scans acquired on a 1.5 Tesla scanner using a validated semi-quantitative scale.

RESULTS

We found mostly low grade WMHs in all groups. The proportion of WMH-positive subjects was comparable between the unaffected high-risk, affected familial and control groups.

CONCLUSION

White matter hyperintensities did not meet criteria for an endophenotype of BD. Bipolar disorder in young subjects without comorbid conditions was not associated with increased rate of WMHs.

A study of ACE and ADD1 polymorphism in ischemic and hemorrhagic stroke

BACKGROUND

Stroke is a common cerebrovascular accident. ACE and ADD1 gene are known to be associated with vascular complications leading to stroke susceptibility. The present study was carried out to evaluate the relative frequency of ACE and ADD1 common polymorphisms in ischemic stroke and intracerebral hemorrhage (ICH).

METHODS

A total of 386 CT or MRI proven stroke patients were included; 193 each had ischemic stroke and ICH. The locations and type of stroke were noted. ACE- I/D (rs4646994) and ADD1 (rs4961) gene polymorphisms were analyzed by polymerase chain reaction (PCR). The genotype and allele frequencies of ACE and ADD1 polymorphisms were compared between patients and controls as well as between ischemic stroke and ICH.

RESULTS

ACE (DD) genotype was significantly higher in ischemic stroke (37.8%) and ICH (33.7%) compared to controls (11.7%). D allele was also more frequent in ischemic stroke (57.3%) and ICH (56.7%) compared to controls (38.3%). ADD1 (WW) genotype and W allele frequencies were not significantly different in ischemic stroke, ICH and controls. In contrast, we found a synergistic role of ACE (DD)*ADD1(GW) interaction showing a positive association in both ischemic and hemorrhagic strokes.

CONCLUSION

Our study suggests that ACE (DD) genotype and D allele significantly increase the susceptibility to ischemic and hemorrhagic strokes.

ACE I/D polymorphism affects cognitive function and gray-matter volume in amnestic mild cognitive impairment

To characterize the correlates of cognitive function, serum concentrations of angiotensin converting enzyme (ACE) and brain structure with the ACE insertion or deletion (I/D) polymorphism were analyzed in subjects with amnestic-mild cognitive impairment (aMCI). A group of 48 subjects meeting criteria for aMCI and 36 age-matched control subjects were assessed using a comprehensive battery of standardized neuropsychological tests and magnetic resonance imaging (MRI). The ACE gene's I/D polymorphism was analyzed by means of PCR, and serum ACE concentrations were measured using ultraviolet spectrophotometry. Genotype effects on neuropsychological domains and MRI gray matter volume (GMV) measurements (optimized voxel-based morphometry) were examined using general linear models. The D carriers among the aMCI subjects performed significantly worse on AVLT-delayed recall compared to the I homozygous group. The D carriers had higher serum ACE concentrations than did the I homozygous carriers, though this difference only reached statistical significance in the aMCI group. Compared with the I homozygous carriers, in the aMCI group, D carriers showed smaller GMV of the bilateral middle frontal gyrus, right cuneus, right precentral gyrus, right medial frontal gyrus, right superior frontal gyrus, and left postcentral gyrus. However, there was no significant difference in GMV between I homozygous and D carriers in the normal control group. The study suggests that ACE genotype has considerable effect on the cognitive performance of aMCI subjects, particularly episodic memory, serum activity of ACE, and the structure of specified brain regions. The ACE D allele may be a genetic risk factor for greater atrophy of gray matter in aMCI.

Risk of "silent stroke" in patients older than 60 years: risk assessment and clinical perspectives

With the increasing size of the elderly population and evolving imaging technology, silent brain infarction (SBI) has garnered attention from both the public and the physicians. Over 20% of the elderly exhibit SBI, and the prevalence of SBI increases steadily with age, ie, 30%–40% in those older than 70 years. Well-known cardiovascular risk factors such as hypertension has been identified as a risk factor of SBI (odds ratio [OR] = 3.47) Besides this, blood pressure (BP) reactivity to mental stress, morning BP surges, and orthostatic BP changes have been demonstrated to contribute to the presence of SBI. Further, a metabolic syndrome not only as a whole syndrome (OR =2.18) but also as individual components could have an influence on SBI. Increased C-reactive protein and interleukin-6, coronary artery disease, body mass index, and alcohol consumption have also been associated with SBI. The ORs and possible mechanisms have been discussed in this article. Overt stroke, dementia, depression, and aspiration pneumonia were all associated with SBI. (overt stroke: hazard ratio [HR] =1.9, 95% confidence interval [CI]: 1.2–2.8; dementia: HR =2.26, 95% CI: 1.09–4.70). We also looked into their close relationship with SBI in this review.

Angiotensin-converting enzyme insertion/deletion polymorphism has no effect on the risk of atherosclerotic stroke or hypertension

BACKGROUND AND PURPOSE

Stroke is a heterogeneous multifactorial disease. Hence, a large number of candidate genes are involved in stroke pathophysiology, such as blood pressure regulation and atherosclerosis. Although angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism is considered to have a role in hypertension, coronary artery disease, and myocardial infarction, its relationship with cerebrovascular disease and hypertension in stroke in different ethnic populations is still inconsistent.

METHODS

ACE I/D polymorphism, detected by polymerase chain reaction (PCR), was studied in 97 patients with large-vessel and 60 patients with small-vessel atherosclerotic stroke (44 asymptomatic, 16 symptomatic lacunes) and 85 healthy subjects with normal brain imaging. The demographic data, lipid profile and risk factors of patients and controls were obtained retrospectively.

RESULTS

ACE genotypes were in Hardy-Weinberg equilibrium in both patients and controls. Prevalences of DD, ID and II genotype were 41%, 40%, and 19%, respectively, in the stroke group. Differences in ACE I/D polymorphism distribution were statistically insignificant between the groups. This lack of association between stroke and ACE I/D polymorphism did not change in the presence of traditional risk factors (hypertension, diabetes mellitus, smoking, and dyslipidemia). Although hypertension was significantly more common in the patient groups, ACE I/D polymorphism showed no effect on hypertension risk. This lack of association also did not change according to groups or in the presence of diabetes mellitus, male gender or smoking.

CONCLUSION

ACE I/D polymorphism did not predict the risk of stroke or hypertension in our population living in the western Black Sea region of Turkey.

Pathophysiology of vascular dementia

The concept of Vascular Dementia (VaD) has been recognized for over a century, but its definition and diagnostic criteria remain unclear. Conventional definitions identify the patients too late, miss subjects with cognitive impairment short of dementia, and emphasize consequences rather than causes, the true bases for treatment and prevention. We should throw out current diagnostic categories and describe cognitive impairment clinically and according to commonly agreed instruments that document the demographic data in a standardized manner and undertake a systematic effort to identify the underlying aetiology in each case. Increased effort should be targeted towards the concept of and criteria for Vascular Cognitive Impairment and Post-Stroke Dementia as well as for genetic factors involved, especially as these categories hold promise for early prevention and treatment.

Migraine as a systemic vasculopathy

Epidemiological studies suggests that migraine is associated with disorders of the cerebral, coronary, retinal, dermal and peripheral vasculature. There is evidence that migraine is associated with endothelial dysfunction, both as a cause and a consequence. Endothelial dysfunction, a vascular risk factor, is characterized by endothelial activation and impaired vascular reactivity. Plasma and genetic biomarkers for these conditions have been identified. The clinical significance lies in the potential for the rapid identification of migraineurs at increased risk of ischaemic stroke and vascular disease through ascertainment of endothelial dysfunction biomarkers. It is uncertain whether stroke, myocardial infarction and other vasculopathies can be prevented by migraine prophylaxis, endothelial repair, platelet inhibition or a combination of these strategies.

Hypertension and cognitive function

Cumulative evidence implicates hypertension in the pathogenesis of Alzheimer disease. Although it may not presently be possible to completely differentiate the effects of treatment and control of hypertension itself from those of the medication used to achieve such treatment goals, efforts directed at the treatment and control of hypertension can have significant public health impact.

Angiotensin-converting enzyme polymorphisms and risk of spontaneous deep intracranial hemorrhage in Taiwan

BACKGROUND AND PURPOSE

This study examines whether angiotensin-converting enzyme (ACE) gene polymorphisms are associated with the risk of spontaneous deep intracerebral hemorrhage (SDICH) in Taiwan using a case-control study.

METHODS

Totally, 217 SDICH patients and 283 controls were recruited. Associations of ACE A-240T and ACE I/D polymorphisms with SDICH were examined under the additive model and adjusted for gender, age, body mass index, total cholesterol level, smoking history, alcohol use, hypertension, and use of ACE inhibitors.

RESULTS

Hypertension, diabetes mellitus, family history of spontaneous intracerebral hemorrhage (SICH), and low cholesterol level increase risk of female SDICH, whereas hypertension, alcohol use, smoking history, family history of SICH, and low cholesterol level are an important risk factor for male SDICH. After adjusting for covariates, only haplotype ACE T-D (OR = 2.7, 95% CI, 1.1-6.5, P = 0.02) was associated with female SDICH.

CONCLUSIONS

This study demonstrates that environmental risk factors play a major role and ACE polymorphisms play a minor role in contributing risk of SDICH in Taiwan.

Angiotensin-converting enzyme insertion/deletion polymorphism and the risk of ischemic stroke in a South Indian population

Stroke is one of the most complex diseases with several subtypes, arising from numerous gene-gene and gene-environmental interactions. The aim of our study was to investigate whether the insertion/deletion polymorphism in Angiotensin-converting enzyme gene is associated with ischemic stroke in a South Indian population. One hundred and sixty two patients and one hundred and fifty controls were studied for the presence of ACE gene polymorphism by PCR technique. The stroke patients were subtyped according to TOAST criteria, taking into account all the available data. There were significant differences in the genotypic distribution and allelic frequency between the patients and healthy controls. Furthermore the D allele was significantly associated with intracranial large artery atherosclerosis. However, the association was insignificant with other stroke subtypes. We observed that ACE ID/DD genotypes are associated with an elevated incidence of stroke in a South Indian population from Andhra Pradesh. Moreover, ACE gene polymorphism was found to contribute to the risk of developing intracranial large artery atherosclerosis, which is the most frequent subtype in this region.

Cerebral small vessel disease: genetic risk assessment for prevention and treatment

Cerebrovascular disease is a major burden to individuals and their communities worldwide. Stroke is one of the leading causes of death and disability, and the prevention and treatment of stroke can be improved with a better understanding of its causation. Cerebral small vessel disease (SVD) is a subset of cerebrovascular disease, and has an equally large impact on an individual's quality of life. Although many risk factors are involved, we propose that genetics has a significant role in the pathogenesis of SVD through a complex interplay of environmental and multigenetic factors. Advances in molecular technology have enabled the human genome to be investigated both at a population and, more recently, an individual level. A better understanding of the molecular basis of SVD will enable the development of therapies to help in its prevention and treatment. This review assesses the molecular genetics underlying cerebral SVD.

White matter hyperintensities in mid-adult life

PURPOSE OF REVIEW

White matter hyperintensities on T2-weighted magnetic resonance imaging are frequent incidental findings in the brains of elderly individuals. Recent studies have reported that they may also be common in middle-aged individuals, and their systematic evaluation in younger populations is necessary.

RECENT FINDINGS

Incidental white matter hyperintensities are common in brains of healthy individuals in their 60s and may be seen as early as the 30s and 40s. They are associated with subtle functional impairment and higher prevalence of neuropsychiatric disorders. While cerebrovascular risk factors such as hypertension, diabetes, high homocysteine, and so forth, are known risk factors for white matter hyperintensities, a significant proportion of the variance is unexplained. Genetic factors, alone or in interaction with environmental factors, appear to be important. There is a slight excess of white matter hyperintensities in women, the basis for which is not understood. Longitudinal studies show that those with baseline lesions have a greater progression over time.

SUMMARY

New imaging techniques present an opportunity to examine white matter pathology in great detail in younger populations. Standardized methods to examine such pathology and its determinants will help inform strategies for their prevention, which is an important component of a healthy ageing agenda.

Prevalence of Thrombophilic Mutations and ACE I/D Polymorphism in Turkish Ischemic Stroke Patients

The aim of this study was to evaluate the prevalence of factor V Leiden (FVL), prothrombin G20210A, methylenetetrahydrofolate reductase ( MTHFR) C677T gene mutations, and angiotensin-converting enzyme (ACE) I/D polymorphism in ischemic stroke (IS) patients. A total of 162 Turkish IS patients were included and analyzed according to stroke subtype by the TOAST classification. Their genotype data were compared with those of the control group, representing the healthy population, using the χ2 test. The frequency of FVL heterozygocity was 12.3% in this series—higher than that in the normal population (9.8%; statistically insignificant, P = .478). The frequency of the ACE D/D genotype in all stroke patients and those with stroke of undetermined etiology was higher than that in our population (52.5% and 59.2%, respectively, vs 39.3%; statistically significant, P = .034, P = .020). Our results may suggest that ACE D/D genotype is a risk factor for IS, particularly in those with stroke of undetermined etiology in the Turkish population.

Genes, endothelial function and cerebral small vessel disease in man

Cerebral small vessel disease results from ischaemia in the perforating arteries supplying the white matter and deep grey matter nuclei. It results in both focal lacunar infarction and more diffuse areas of chronic ischaemia (leukoaraiosis). Two subtypes may exist. One subtype (isolated lacunar infarction) is associated with single or a few larger lacunar infarcts without leukoaraiosis, and may result from microatheroma in the larger perforating arteries. The second subtype (ischaemic leukoaraiosis) results in multiple small lacunar infarcts with leukoaraiosis secondary to a diffuse arteriopathy affecting the smaller perforating arteries, usually occurring in the presence of hypertension. In this subtype, chronic hypoperfusion and impaired cerebral autoregulation have been reported. A number of lines of evidence support a pathogenic role of endothelial activation and dysfunction. Genetic predisposition has also been implicated. Associations with genes involved in endothelial function, including those regulating the renin-angiotensin system, endothelial nitric oxide and homocysteine levels, have been reported. However, not all results have been replicated and there are few robust replicable associations. Larger studies are required to determine definitively which associations represent important risk factors.

Migraine and ischaemic heart disease and stroke: potential mechanisms and treatment implications

The migraine-ischemia relationship is best understood in the context of the pathophysiology of migraine. Potential mechanisms of migrainous infarction (stroke occurring during migraine) include vasospasm, hypercoagulability, and vascular changes related to cortical spreading depression. Stroke occurring remote for the migraine attack may be related to arterial dissection, cardioembolism, and endothelial dysfunction. Endothelial dysfunction, a process mediated by oxidative stress, may be a cause or a consequence of migraine, and explain the relationship of migraine to vascular factors and ischemic heart disease. It remains uncertain whether stroke or myocardial infarction can be prevented by migraine prophylaxis, endothelial repair, platelet inhibition, or a combination of these strategies. Although triptans are generally considered safe for use in migraine, caution is warranted in those with multiple vascular risk factors. Known vascular disease is a contraindication to triptan use.

Recent advances in stroke management

Major advances in stroke treatment and prevention have, occurred over the last several years. Recent studies have documented that appropriate modification of stroke risk factors can lead to, a substantial reduction in stroke incidence. In addition, a variety of new risk factors, such as elevated plasma homocysteine levels, antiphospholipid antibodies, and specific genetic factors, are being recognized. The most significant advance in acute stroke therapy is the use of intravenous tissue plasminogen activator, (t-PA) for treatment of patients with ischemic stroke within 3 hours of symptom onset. T-PA is currently the only stroke treatment approved by the Federal Drug Administration. There continues to be uncertainty and misunder-standing regarding the risks and benefits of this therapy. A variety of neuroprotective agents have been highly successful for reducing ischemic brain injury in animal stroke models. Recent clinical trials with these agents, however, have not produced beneficial effects in humans. Newer neuroprotective agents with more favorable safety profiles and improvements in clinical trial design may lead to therapeutic successes in the near future. It is apparent that both thrombolytic and neuroprotective treatments for acute stroke must be administered very rapidly, after stroke onset. Therefore, acute stroke teams are being developed to facilitate rapid diagnostic evaluation and treatment of stroke patients.

Effects of angiotensin-converting enzyme gene polymorphism and serum vitamin D levels on ambulatory blood pressure measurement and left ventricular mass in Turkish hypertensive population

INTRODUCTION

Regulation of angiotensin converting enzyme (ACE) and angiotensin II (ang-II) levels is under genetic control. 1,25(OH)2 vitamin D3 treatment has been shown to reduce the ang-II level, reduce myocardial hypertrophy and to decrease blood pressure. This study was designed to examine the effect of ACE gene polymorphisms on 24-h ambulatory blood pressure measurement (24 h) values, vitamin D levels and target organ damage in hypertensive patients.

METHODS

This study was carried on 118 patients with essential hypertension (female/male: 70/48, mean age: 49.1+/-7.6 years, hypertension duration: 56+/-40.5 months). All patients were assessed for target organ damage; the eye by retinal examination, the heart with echocardiography and the kidney with blood and 24-h urine analysis. 24-h ambulatory blood pressure measurement was performed in all patients. PCR amplification was employed to detect ACE genotypes.

RESULTS

ACE genotypes were as follows: DD (n=49) 41.5%; ID (n=37) 31.4% and II (n=32) 27.1%. No difference was present between groups of ACE polymorphism when 24-h ambulatory blood pressure measurement values, retinal vascular changes and microalbuminuria were taken into account. Statistically significant left ventricular mass index levels were obtained in the DD group when compared with the non-DD (ID+II) group (P : 0.009). Positive correlations have been noted between left ventricular mass index and day/night and early morning systolic pressures. A negative correlation exists between serum 25 (OH) vitamin D levels and 24-h ambulatory blood pressure measurement values (P<0.05).

CONCLUSIONS

The presence of the D allele is linked with a higher risk for left ventricular mass index in the Turkish hypertensive population.

Validation of the association between the gene encoding proteasome subunit alpha type 6 and myocardial infarction in a Japanese population

BACKGROUND

Recently, a large case-control study (2,851 cases and 2,592 controls) reported that a functional single nuclear polymorphism (SNP) in the proteasome subunit alpha type 6 gene (PSMA6) conferred a risk of myocardial infarction (MI) in a Japanese population. The SNP (exon 1, -8C/G) is located in the 5' untranslated region of exon 1, and the risk-conferring allele G appears to enhance the transcription of PSMA6, which may exaggerate inflammation through activation of nuclear factor-kappa beta protein. The frequency of the risk conferring genotype (GG) in cases was reported to be greater than that in controls (12.4% vs 8.9%). The purpose of the present study was to validate this observation in our study population.

METHODS AND RESULTS

Subjects with MI (n=433) were recruited from the outpatient clinic of the National Cardiovascular Center. Control subjects (n=2,186) were recruited from the Suita study. The frequencies of the GG genotype did not significantly differ between the control (9.8%) and MI groups (10.6%). Moreover, this genotype was not associated with C reactive protein levels in the Suita study. However, the GG genotype was significantly associated with greater intima-media thickness (n=2,051, p=0.015) after adjusting for blood pressure, sex, body mass index and age in the Suita study.

CONCLUSION

The reported genotype in PSMA6 appears not to contribute appreciably to MI, but may contribute slightly to atherosclerosis in the present study population.

Family history of hypertension is not an independent genetic factor predisposing to ischemic stroke subtypes

OBJECTIVES

The effect of family history of hypertension (FHx(HT)), as a genetic factor predisposing to some ischemic stroke subtypes and independently of hypertension as risk factor, has never been studied.

METHODS

A positive FHx(HT) was searched in 472 patients (312 men, 160 women; mean [S.D.] age, 67.9 [11.4] years) consecutively admitted for a first-ever ischemic stroke (348) or transient ischemic attack (TIA) (124) due to small vessel disease (SVD, 180), large vessel disease (156), or cardioembolism (136). In this population and in three age bands, the genetically transmitted vascular risk factors, age, gender and the ischemic stroke subtypes were compared between those with and without a positive FHx(HT).

RESULTS

None of the risk factors was associated with a positive FHx(HT), except for hypertension in the whole population (68.9% vs. 48.7%; p=0.001) and in the <65 year-old patients (72.5% vs. 39.5%; p<0.001). Regarding the stroke subtypes, a positive FHx(HT) was only associated with SVD in the subgroup of <65 year-old patients (odd ratios (OR), 2.07; 95% confidence interval (CI), 1.01 to 4.25; p=0.045). However, this finding disappeared in a logistic regression analysis, which only retained hypertension as independently associated with SVD.

CONCLUSIONS

FHx(HT) is not an independent genetic factor predisposing to some aetiological stroke subtypes.

ACE I/D polymorphism in different etiologies of ischemic stroke

OBJECTIVES

Data concerning an association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and ischemic stroke (IS) remain inconsistent. Results of some studies suggest that DD genotype may be a risk factor for small vessel disease (SVD) stroke. Here, we investigated whether this polymorphism is associated with IS of different etiologies in a Polish population.

SUBJECTS AND METHODS

Ischemic stroke etiology was established according to the TOAST criteria. We studied 92 stroke patients with large vessel disease and their 184 matched controls; 96 stroke patients with SVD and 192 controls; 180 patients with cardioembolic stroke (CE) and 180 controls. ACE I/D polymorphism was determined using the polymerase chain reaction method.

RESULTS

The distribution of ACE genotypes and alleles was essentially the same in all analyzed IS subtypes and their matched controls.

CONCLUSIONS

We failed to find an association between ACE polymorphism and etiological subtypes of IS in a Polish population.

C677T methylentetrahydrofulate reductase and angiotensin converting enzyme gene polymorphisms in patients with Alzheimer's disease in Iranian population

In recent years numerous data suggest that vascular risk factors may be play a role in Alzheimer's disease (AD). To determine the association of AD with methylentetrahydrofulate reductase (MTHFR) and angiotensin converting enzyme (ACE) as two main vascular risk factors, we examined MTHFR C677T and ACE insertion/deletion (I/D) gene polymorphism in 117 late-onset AD cases and 125 controls. We found no difference in ACE I/D genotype distribution between AD cases and control (P > 0.05) but there was a significant association between AD and the common MTHFR polymorphism C677T. The T allele conferred an increased risk of AD compared to carrying a C allele (P = 0.001, OR = 1.97, 95% CI: 1.3-2.09). Our result suggests a significant increase in risk of AD in cases with the MTHFR T allele, atleast in the Iranian population.

Are the angiotensin-converting enzyme gene and activity risk factors for stroke?

Stroke is a multifactorial disease in which genetic factors play an important role. This study was carried out to determine angiotensin-converting enzyme (ACE) gene polymorphism in Turkish acute stroke patients and to establish whether there is an association of angiotensin-converting enzyme gene I/D polymorphism with clinical parameters. In this study 185 patients and 50 controls were recruited. We have investigated the association among the allelic distribution of the insertion/deletion (I/D) polymorphism of the ACE gene identified by polymerase chain reaction. Distribution of ACE gene I/D genotypes and allele frequencies in patients were not significantly different from controls. D allele frequencies were 57.8% in patients versus 53.0% in controls and I allele 42.2% versus 47% respectively. History of hypertension, stroke, renal, heart and vessel diseases incidence and age, gender, systolic-diastolic blood pressures and creatinine levels were significantly high in patients. But these results and ACE activities had no significant differences among the ACE genotypes in patients and controls. Our results suggest that the ACE gene polymorphism is not associated with the pathogenesis of stroke in Turkish stroke patients.

Apolipoprotein E, angiotensin-converting enzyme and kallikrein gene polymorphisms and the risk of Alzheimer's disease and vascular dementia

Lipoproteins and vascular factors may play roles in the development of Alzheimer's disease (AD) and/or vascular dementia (VaD). In this study, odd ratios (ORs) and 95% confidence intervals (CIs) for apolipoprotein E (APOE), angiotensin-converting enzyme (ACE), and kallikrein (KLK1) polymorphisms were computed to test their association with the disease by a case-control study. The risk of AD was significantly increased for individuals with APOE varepsilon4 allele (OR = 3.73, 95% CI = 2.38-5.98). The risk of AD was also significant for people with ACE DD genotype, D allele, or T-D haplotype [OR (95% CI) = 4.29 (1.96-10.23), 1.90 (1.35-2.70), or 2.91 (1.71-5.10), respectively]. The above association between ACE-VaD was also strong (p = 0.0012, 0.0050, 0.0007, respectively). Reporter constructs containing the -240 A or T allele displayed similar transcriptional activity in both HEK-293 and IMR-32 cells. Thus, another putative pathogenic marker that is linked with the Alu D allele might affect the risk of AD and VaD in Taiwan.

Evaluation of the angiotensin-converting enzyme insertion/deletion polymorphism and the risk of ischaemic stroke

Angiotensin-converting enzyme (ACE) gene polymorphism has been associated with increased incidence of stroke in some populations, although contradictory results have been reported. The aim of this study was to determine the allelic frequency and the genotypic distribution for ACE gene polymorphism in Turkish patients with ischemic stroke compared to appropriate healthy controls and to correlate the genetic findings with stoke type. One hundred and eight patients with ischemic stroke versus 79 healthy controls were studied for the presence of ACE gene polymorphism detected by PCR. Genotypes were defined as DD, II and ID according to the presence of the D (deletion) and I (insertion) alleles. There was no statistically significant difference in either the genotypic distribution or allelic frequency between the patients versus healthy controls (chi2 = 0.105; df = 1; p = 0.430). There was also no significant difference for ACE genotype distribution and allelic frequency within the stroke group classified according to Bamford criteria (chi2 = 4.827; df = 3; p = 0.185). Our data supports lack of association between DD genotype and/or D allele and ischemic stroke or subtypes of ischaemic stroke in the Turkish population.

Association of angiotensin-converting enzyme DD genotype with 24-h blood pressure abnormalities in normoalbuminuric children and adolescents with Type 1 diabetes

AIMS

To assess the distribution of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in children and adolescents with Type 1 diabetes and to evaluate the association between ACE genotype and blood pressure (BP).

METHODS

ACE genotypes were assessed in 124 normoalbuminuric, clinically normotensive Type 1 diabetic children and adolescents and 120 non-diabetic controls using polymerase chain reaction. Twenty-four-hour ambulatory BP monitoring was undertaken in all patients.

RESULTS

ACE genotypes distributed in patients as follows: 34 (27%) DD, 57 (46%) ID, 33 (27%) II. The distribution was similar in the control group: DD in 28% (33), ID in 45% (54), and II in 27% (33). Patients with DD genotype had higher mean 24-h diastolic BP (73.8 +/- 6.2 vs. 70.2 +/- 5.0 and 69.7 +/- 6.3 mmHg; P = 0.005) and lower diurnal variation in BP (11.8 +/- 4.6 vs. 14.2 +/- 4.2 and 14.8 +/- 4.3%; P = 0.011) compared with ID and II groups. Four patients in the DD group proved to be non-dipper compared with one in the ID and none in the II group (P = 0.026). Twenty-four-hour diastolic blood pressure was independently predictive for AER as dependent variable in the DD genotype patient group (r(2) = 0.12, P = 0.03).

CONCLUSIONS

Children and adolescents with Type 1 diabetes do not differ from the non-diabetic population regarding the I/D polymorphism of the ACE gene. ACE gene polymorphism is associated with BP abnormalities in normotensive and normoalbuminuric children and adolescents with Type 1 diabetes.

Association of the insertion/deletion polymorphism of the angiotensin I-converting enzyme gene in patients of migraine with aura

Recently, several angiotensin I-converting enzyme (ACE) inhibitors and an angiotensin II receptor blocker were demonstrated to have a clinically important prophylactic effect in migraine. ACE is one of the key enzymes in the rennin-angiotensin-aldosterone system, which modulates vascular tension and blood pressure. In humans, serum ACE levels are strongly genetically determined. Individuals who were homozygous for the deletion (D) allele showed increased ACE activity levels. To investigate the role of ACE polymorphism in headache, we analyzed the ACE insertion (I)/deletion (D) genotypes of 54 patients suffering from migraine with aura (MwA), 122 from migraine without aura, 78 from tension-type headache (TH), and 248 non-headache healthy controls. The ACE D allele were significantly more frequent in the MwA than controls (p<0.01). The incidence of the D/D genotype in MwA (25.9%) was significantly higher than that in controls (12.5%; p<0.01; odds ratio=5.26, 95% confidence interval: 1.69-16.34, adjusted for age and gender). No differences in the remaining groups were found. Our results support the conclusion that the D allele and the D/D genotype in the ACE gene is a genetic risk factor for Japanese MwA. There seems to be a possible relationship between ACE activity and the pathogenesis of migraine.

Antihypertensive medications for risk reduction of first and recurrent ischemic stroke

It is increasingly clear that even a small reduction in blood pressure results in a substantial risk reduction of vascular events including ischemic stroke. Recently, several comparative prospective trials of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers have demonstrated that, for equivalent reductions in blood pressure, these drugs may confer a greater effect on the prevention of primary and recurrent ischemic stroke compared with other antihypertensive medications. Given this information from prospective randomized trials, it appears that this class of drugs should be the first-line treatment for hypertension in patients at risk of a first or recurrent ischemic stroke. This review will critically assess the scientific basis and rationale of the use of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers in primary and secondary stroke prevention.