Transcription factor 21 gene and prognosis in a coronary population.

INTRODUCTION AND OBJECTIVES: Transcription factor 21 (TCF21) is a member of the basic helix-loop-helix (bHLH) transcription factor family, and is critical for embryogenesis of the heart. It regulates differentiation of epicardium-derived cells into smooth muscle cell (SMC) and fibroblast lineages. The biological role of TCF21 in the progression of atherosclerosis is the subject of debate. The aim of this study was to investigate the impact of the TCF21 rs12190287 gene variant on the prognosis of coronary artery disease (CAD) in a Portuguese population from Madeira island. METHODS: We analyzed major adverse cardiovascular events (MACE) in 1713 CAD patients, mean age 53.3±7.8, 78.7% male, for 5.0±4.3 years. Genotype and allele distribution between groups with and without MACE was determined. The dominant genetic model (heterozygous GC plus homozygous CC) was used and compared with the wild GG to assess survival probability. Cox regression with risk factors and genetic models assessed variables associated with MACE. Kaplan-Meier analysis was used to estimate survival. RESULTS: The wild homozygous GG, heterozygous GC and risk CC genotypes were found in 9.5%, 43.2% and 47.3% of the population, respectively. The dominant genetic model remained in the equation as an independent risk factor for MACE (HR 1.41; p=0.033), together with multivessel disease, chronic kidney disease, low physical activity and type 2 diabetes. The C allele in the dominant genetic model showed worse survival (22.5% vs. 44.3%) at 15 years of follow-up. CONCLUSION: The TCF21 rs12190287 variant is a risk factor for CAD events. This gene may influence fundamental SMC processes in response to vascular stress, accelerating atherosclerosis progression, and may represent a target for future therapies.

Impact of genetic information on coronary disease risk in Madeira: The GENEMACOR study.

INTRODUCTION: Coronary artery disease (CAD), characterized by an atherogenic process in the coronary arteries, is one of the leading causes of death in Madeira. The GENEMACOR (GENEs in MAdeira and CORonary Disease) study sought to investigate the main risk factors - environmental and genetic - and estimate whether a genetic risk score (GRS) improves CAD prediction, discrimination and reclassification. METHODS: Traditional risk factors and 33 CAD genetic variants were considered in a case-control study with 3139 individuals (1723 patients and 1416 controls). The multivariate analysis assessed the likelihood of CAD. A multiplicative GRS (mGRS) was created, and two models (with and without mGRS) were prepared. Two areas under receiver operating characteristic curve (area under curve (AUC)) were analyzed and compared to discriminate CAD likelihood. Net reclassification improvement (NRI) and integrated discrimination index (IDI) were used to reclassify the population. RESULTS: All traditional risk factors were strong and independent predictors of CAD, with smoking being the most significant (OR 3.25; p<0.0001). LPA rs3798220 showed a higher CAD likelihood (odds ratio 1.45; p<0.0001). Individuals in the fourth mGRS quartile had an increased CAD probability of 136% (p<0.0001). A traditional risk factor-based model estimated an AUC of 0.73, rising to 0.75 after mGRS inclusion (p<0.0001), revealing a better fit. Continuous NRI better reclassified 28.1% of the population, and categorical NRI mainly improved the reclassification of the intermediate risk group. CONCLUSIONS: CAD likelihood was influenced by traditional risk factors and genetic variants. Incorporating GRS into the traditional model improved CAD predictive capacity, discrimination and reclassification. These approaches may provide helpful diagnostic and therapeutic advances, especially in the intermediate risk group.

WITHDRAWN: Impact of genetic information on Coronary Disease risk in Madeira: The GENEMACOR study.

The Publisher regrets that this article is an accidental duplication of an article that has already been published, 10.1016/j.repc.2022.10.005. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

[Genetic Polymorphisms Associated with the Onset of Arterial Hypertension in a Portuguese Population]. / Polimorfismos Genéticos Associados ao Aparecimento de Hipertensão Arterial Numa População Portuguesa.

INTRODUCTION: Arterial hypertension is a complex, multifactorial disease, controlled by genetic and environmental factors. OBJECTIVE: Evaluate the genetic susceptibility for developing arterial hypertension and its association with the traditional risk factors in the outbreak of this pathology. MATERIAL AND METHODS: Case-control study with 1712 individuals, mean age of 51.0 ± 7.9 years (860 hypertensive patients and 852 controls). Biochemical and traditional risk factors, and genetic variants were evaluated: ACE I/D rs4340, ACE A2350G rs4343, AGT T174M rs4762, AGT M235T rs699 AGTR1 A1166C rs5186, CYP11B2 -344 C/T rs1799998, ADRB1 R389G rs1801253, ADRB2 R16G rs1042713, ADD1 G460W rs4961, SCNN1G G173A rs5718, GNB3 C825T rs5443, ATP2B1 A/G rs2681472, CYP17A1 T/C rs11191548, SLC4A2 C/T rs2303934. The risk of each gene for hypertension was estimated by the dominant, recessive, co-dominant and multiplicative models. By logistic regression, variables associated with hypertension were evaluated. ROC curves were first performed with traditional risk factors and then adding the genetic variants associated with hypertension. Data were analyzed by SPSS for Windows 19.0 and MedCalc v. 13.3.3.0. RESULTS: The genetic variants ADD1 G460W, GNB3 C825T, ACE I/D, ACE A2350G were associated with hypertension. ROC curve with traditional risk factors and these variants showed an increase in the predictive capacity of hypertension (p = 0.018). DISCUSSION: According to the results of our study, the genetic variants found to be associated with hypertension were: ACE I/D rs4340, ACE A2350G rs4343, ADD1 G460W rs4961 and GNB3 C825T rs5443. The first two variants are associated with hypertension by interfering with the renin-angiotensin-aldosterone system, which plays an important role in regulating blood pressure. It should be noted that genes encoding the components of renin-angiotensin-aldosterone system are natural candidates for the development and progression of hypertension. In our population alpha-aducin polymorphism (ADD1 G460W rs4961) was also associated with hypertension. In a Portuguese population, known to have high salt intake, it makes sense that this polymorphism which is relevant in salt and water management may consequently be relevant in the onset of hypertension. The genetic variant GNB3 C825T rs5443 that affects intracellular signalling was also found to be a strong risk candidate for hypertension. Initially, with the elaboration of the ROC curve and calculation of the AUC using only with traditional risk factors and later by adding the variants ADD1 G460W, GNB3 C825T, ACE I/D and ACE A2350G to the traditional risk factors, we verified that genetic polymorphisms increased the predictive risk of hypertension, when compared to the risk given only by traditional risk factors, with statistical significance (p = 0.018). This suggests that hypertension is a multifactorial disease that results from the interaction of environmental, genetic and lifestyle factors that interact with each other and lead to the advent of this important pathology. CONCLUSION: In our study, the hypertension-associated polymorphisms are linked to the renin-angiotensin-aldosterone axis (ACE I/D, ACE A2350G), as well as to salt and water management (ADD1 G460W, GNB3 C825T). Through a multivariate analysis, it was concluded that these two last genetic variants together with four of the traditional risk factors (smoking, alcohol consumption, obesity and diabetes) are associated in a significant and independent way with essential hypertension. In a predictive model of hypertension, the introduction of genetic variants slightly increases the predictive value of the model.

Introdução: A hipertensão arterial é uma doença complexa, multifatorial, controlada por fatores genéticos e ambientais.Objetivo: Avaliar a susceptibilidade genética no aparecimento de hipertensão arterial e sua associação com os fatores de risco tradicionais na eclosão desta patologia.Material e Métodos: Estudo caso-controlo com 1712 indivíduos, idade média de 51,0 ± 7,9 anos (860 hipertensos e 852 controlos). Avaliaram-se os fatores tradicionais, bioquímicos e as variantes genéticas: ACE I/D rs4340, ACE A2350G rs4343, AGT T174M rs4762, AGT M235T rs699 AGTR1 A1166C rs5186, CYP11B2 -344 C/T rs1799998, ADRB1 R389G rs1801253, ADRB2 R16G rs1042713, ADD1 G460W rs4961, SCNN1G G173A rs5718, GNB3 C825T rs5443, ATP2B1 A/G rs2681472, CYP17A1 T/C rs11191548, SLC4A2 C/T rs2303934. Calculámos o risco de cada gene para a hipertensão, pelos modelos dominante, recessivo, co-dominante e multiplicativo. Através da regressão logística, avaliámos as variáveis associadas à hipertensão. Elaboraram-se curvas ROC com os fatores tradicionais e posteriormente adicionando as variantes genéticas associadas com hipertensão. Analisámos os dados através do SPSS for Windows 19.0 e MedCalc v. 13.3.3.0.Resultados: As variantes genéticas ADD1 G460W, GNB3 C825T, ACE I/D e ACE A2350G associaram-se à hipertensão. A curva ROC com os factores de risco tradicionais e estas variantes mostrou um incremento na capacidade preditiva de hipertensão (p = 0,018).Discussão: Segundo os resultados do nosso estudo as variantes genéticas que após análise univariada se associaram à hipertensão arterial foram a ACE I/D rs4340, ACE A2350G rs4343, ADD1 G460W rs4961, GNB3 C825T rs5443. As duas primeiras variantes relacionam-se com a hipertensão arterial por interferirem no sistema renina-angiotensina-aldosterona, que tem um importante papel na regulação da pressão arterial. Salienta-se o facto dos genes que codificam os componentes do sistema renina-angiotensinaaldosterona serem candidatos naturais ao desenvolvimento e progressão da hipertensão arterial. Também na nossa população os polimorfismos da alfa-aducina (ADD1 G460W rs4961), associaram-se à hipertensão arterial. Nesta população portuguesa, conhecida por ter elevado consumo de sal, faz sentido que estes polimorfismos, sejam relevantes na gestão do sal e da água e consequentemente, no aparecimento de hipertensão arterial. A variante genética GNB3 C825T rs5443 que interfere na sinalização intracelular também constituiu uma forte candidata à hipertensão arterial. Com a elaboração da curva ROC e cálculo das AUC inicialmente só com os fatores de risco tradicionais e posteriormente adicionando as variantes ADD1 G460W, GNB3 C825T, ACE I/D e ACE A2350G aos fatores de risco tradicionais, verificámos ter havido um incremento no risco preditivo de hipertensão arterial, relativamente ao existente só com os fatores de risco tradicionais, com significado estatístico (p = 0,018). Isto sugere que a hipertensão arterial é uma doença multifatorial, que resulta da interação de fatores ambientais, genéticos e estilos de vida que interagem entre si e levam ao aparecimento desta importante patologia.Conclusão: No nosso estudo os polimorfismos associados à hipertensão, estão ligados ao eixo renina-angiotensina-aldosterona (ACE I/D, ACE A2350G), bem como à gestão de sal e água (ADD1 G460W, GNB3 C825T). Através de uma análise multivariada, concluiu-se que estas duas últimas variantes genéticas conjuntamente com quatro dos fatores tradicionais (tabagismo, hábitos alcoólicos, obesidade e diabetes) se associam de forma significativa e independente à hipertensão arterial essencial. Num modelo preditivo de hipertensão arterial, a introdução das variantes genéticas aumenta ligeiramente o valor preditivo do modelo.

The genetic variant C825T of the beta 3 subunit of G protein is associated with hypertension in a Portuguese population. / A variante genética c825t da subunidade ß3da proteína G associa­se com a hipertensão arterial numa população portuguesa.

INTRODUCTION: Hypertension is an important public health problem, affecting about 25% of the adult population worldwide.1 Genetic and environmental factors contribute to its pathogenesis. The T allele of the C825T polymorphism of the beta 3 subunit of G protein (rs5443) leads to the production of a truncated variant that enhances intracellular signaling and may interfere with the regulation of blood pressure. This genetic variant has been described as a risk factor for hypertension, although study results are controversial. OBJECTIVE: The objective of this study was to analyze the association of the C825T polymorphism of the GNB3 gene with the occurrence of hypertension in a Portuguese population from the Madeira archipelago. METHODS: A case-control study was performed with 1641 Caucasian individuals (mean age 50.6±8.1 years), 848 with hypertension and 793 controls. Blood was collected from all participants for biochemical and genetic analysis, including genotyping of the C825T polymorphism. Logistic regression analysis was performed to determine which variables were significantly associated with the onset of hypertension. Statistical analyses were performed using IBM SPSS version 19.0 and p-values <0.05 were considered statistically significant. RESULTS: In our study, there was a significant association between the C825T polymorphism of the GNB3 gene and the occurrence of hypertension (odds ratio 1.275; 95% confidence interval 1.042-1.559; p=0.018) in the dominant model, after multivariate analysis. CONCLUSION: We conclude that the C825T polymorphism of the beta 3 subunit of G protein is significantly and independently associated with the occurrence of hypertension in the study population.

Relationship between ADD1 Gly460Trp gene polymorphism and essential hypertension in Madeira Island.

Essential hypertension (EH) is a complex disease in which physiological, environmental, and genetic factors are involved in its genesis. The genetic variant of the alpha-adducin gene (ADD1) has been described as a risk factor for EH, but with controversial results.The objective of this study was to evaluate the association of ADD1 (Gly460Trp) gene polymorphism with the EH risk in a population from Madeira Island.A case-control study with 1614 individuals of Caucasian origin was performed, including 817 individuals with EH and 797 controls. Cases and controls were matched for sex and age, by frequency-matching method. All participants collected blood for biochemical and genotypic analysis for the Gly460Trp polymorphism. We further investigated which variables were independently associated to EH, and, consequently, analyzed their interactions.In our study, we found a significant association between the ADD1 gene polymorphism and EH (odds ratio 2.484, P = .01). This association remained statistically significant after the multivariate analysis (odds ratio 2.548, P = .02).The ADD1 Gly460Trp gene polymorphism is significantly and independently associated with EH risk in our population. The knowledge of genetic polymorphisms associated with EH is of paramount importance because it leads to a better understanding of the etiology and pathophysiology of this pathology.

Genetic risk score and cardiovascular mortality in a southern european population with coronary artery disease.

Several genetic risk scores (GRS) have been associated with cardiovascular disease; their role, however, in survival from proven coronary artery disease (CAD) have yielded conflicting results. OBJECTIVE: The objective of this study was to evaluate long-term cardiovascular mortality according to the genetic risk score in a Southern European population with CAD. METHODS: A cohort of 1464 CAD patients with angiographic proven CAD were followed up prospectively for up to 58.3 (interquartile range: 25.8-88.1) months. Genotyping of 32 single-nucleotide polymorphisms previously associated with CAD was performed using oligonucleotides probes marked with fluorescence for each allele. GRS was constructed according to the additive model assuming codominance and categorised using the median (=26). Cox Regression analysis was performed to determine independent multivariate predictors of cardiovascular mortality. Kaplan-Meier survival curves compared high vs low GRS using log-rank test. C-index was done for our population, as a measure of discrimination in survival analysis model. RESULTS: During a mean follow-up of 58.3 months, 156 patients (10.7%) died, 107 (7.3%) of CV causes. High GRS (≥26) was associated with reduced cardiovascular survival. Survival analysis with Cox regression model adjusted for 8 variables showed that high GRS, dyslipidemia, diabetes and 3-vessel disease were independent risk factors for cardiovascular mortality (HR=1.53, P=.037; HR=3.64, P=.012; HR=1.75, P=.004; HR=2.97, P<.0001, respectively). At the end of follow-up, the estimated survival probability was 70.8% for high GRS and 80.8% for low GRS (Log-rank test 5.6; P=.018). C-Index of 0.71 was found when GRS was added to a multivariate survival model of diabetes, dyslipidemia, smoking, hypertension and 3 vessel disease, stable angina and dual antiplatelet therapy. CONCLUSIONS: Besides the classical risk factors management, this work highlights the relevance of the genetic profile in survival from CAD. It is expected that new therapies will be dirsected to gene targets with proven value in cardiovascular survival.

Independent association of the variant rs1333049 at the 9p21 locus and coronary heart disease.

INTRODUCTION: Recent genome-wide association studies have identified single-nucleotide polymorphisms (SNPs) at the 9p21 locus as risk factors for coronary artery disease (CAD). Among them, the SNP rs1333049 has demonstrated a consistent association with CAD, which has been successfully replicated in several populations. AIM: To investigate whether the SNP rs1333049 located on the 9p21 chromosome is an independent risk factor for CAD in a Portuguese population. METHODS: We performed a case-control study which included 1406 individuals, 723 consecutive coronary patients (mean age 53.71 +/- 8.9 years, 79.9% male and 683 controls without coronary disease (mean age 53.3 +/- 10.5 years, 73.9% male). Cases and controls were selected so as not to be significantly different in terms of gender and age. We studied the SNP rs1333049 at the 9p21 locus in all individuals, using standard PCR combined with the TaqMan technique (Applied Biosystems). The allelic and genotype distribution (C/G), odds ratios and corresponding confidence intervals for CAD risk were determined. A forward Wald logistic regression analysis model was constructed, adjusted for age, gender, conventional risk factors, biochemical markers and the genotypes under study, in order to determine which variables were linked significantly and independently with CAD. RESULTS: The C allele was found in 60% of the CAD patients and 53% of the controls, with OR = 1.33; p = 0.0002. The CC genotype appeared in 35.7% of CAD patients, with OR = 1.34, p = 0.010. The heterozygous CG genotype was present in 48.1% of the CAD patients and 47% of the controls, and did not present vascular risk (OR = 1.05, p = 0.670). After logistic regression analysis, the CC genotype remained in the equation with OR = 1.7; p = 0.018 and CG with OR = 1.5, p = 0.048. CONCLUSION: In the present study we replicated the coronary risk linked to the recently discovered variant rs1333049 on the 9p21 chromosome in a Portuguese population. Although the mechanism underlying the risk is still unknown, the robustness of this risk allele in risk stratification for CAD has been consistent, even in very different populations. The presence of the CC or CG genotype may thus prove to be useful for predicting the risk of developing CAD in the Portuguese population.

Interaction of paraoxonase-192 polymorphism with low HDL-cholesterol in coronary artery disease risk.

INTRODUCTION: Coronary artery disease (CAD) is the main cause of mortality in developed countries. Increased lipid peroxidation is associated with accelerated progression of atherosclerosis. Paraoxonase (PON1) is an antioxidant enzyme bound to high-density lipoprotein (HDL), which protects against lipid peroxidation and coronary artery disease. PON1 activity is under genetic control and its molecular basis is a polymorphism in the PON1 gene that shows two common isoforms: the wild Q form (192 Gln) with high ability to protect LDL from lipid peroxidation in vitro, and the mutated R (Arg) form with lower ability. AIM: To explore the interaction of the R allele of the paraoxonase gene and low HDL-cholesterol concentrations in CAD risk. METHODS: The study population consisted of 818 individuals, 298 coronary patients, aged 55.0 +/- 10.3 years, 78.9% male, and 520 age and gender matched healthy controls, aged 53.3 +/- 11.7 years, 72.5% male. Low HDL-cholesterol was defined as < 0.90 mmol/l in men and < 1.11 mmol/l in women. Comparisons of genotypes between cases and controls were performed by a chi-square test. Statistical significance was accepted at p < 0.05. Odds ratios and 95% confidence intervals for the RR genotypes and HDL-deficient subjects were computed using univariate analysis (2 x 2 tables). To determine the interaction between the RR paraoxonase genotype and HDL-deficient subjects, we used 4 x 2 epidemiologic tables and synergy measures: the additive model (Rothman's synergy index, SI) and multiplicative model (Khoury's synergy index, SIM). The relative excess risk due to interaction (RERI) and the attributable proportion (AP) due to interaction (Rothman) were calculated. RESULTS: The PON1 RR192 polymorphism was associated with coronary heart disease (OR = 1.61; p = 0.043) in the whole population. HDL-deficient subjects with the RR192 genotype showed increased risk for CAD (OR = 17.38; p < 0.0001) compared to those with normal HDL and RR192 (OR = 1.39; p = 0.348) and HDL-deficient subjects not carrying the RR genotype (OR = 7.79; p < 0.0001). Synergy measures were SI = 2.3, SIM = 1.6; RERI = 9.2. CONCLUSION: These data suggest the existence of a synergistic effect of the PON1 RR192 genotype (with lower antioxidant ability) and HDL-deficient subjects in risk for development of CAD. The AP due to this interaction was 0.53, meaning that 53% of CAD was explained by this interaction.

Gene-gene interaction affects coronary artery disease risk.

INTRODUCTION: Various studies have compared coronary artery disease (CAD) patients with controls in order to determine which polymorphisms are associated with a higher risk of disease. The results have often been contradictory. Moreover, these studies evaluated polymorphisms in isolation and not in association, which is the way they occur in nature. OBJECTIVE: Our purpose was to evaluate the risk of CAD in patients with associated polymorphisms in the same gene or in differen genes. METHODS: We evaluated the risk associated with ACE DD, ACE 8 CC, ACT 174MM, AGT 235TT, MTHFR 677TT, MTHFR 1298AA, PON1 192RR and PON1 55MM in 298 CAD patients and 298 healthy individuals. We then evaluated the risk of associated polymorphisms in the same gene (ACE DD + ACE 8GG; AGT 174MM + AGT 235TT; MTHFR 677TT + MTHFR 1298AA). Finally, for the isolated polymorphisms which were significant, we evaluated the risk of polymorphism associations at different functional levels (ACE + AGT; ACE + MTHFR; ACE + PON1). Multiple logistic regression was used to identify independent risk factors for CAD. RESULTS: Isolated polymorphisms including ACE DD(p < 0.0001), ACE 8 gg (p=0.023), and MTHFR 1298AA (p = 0.049) presented with a significantly higher frequency in the CAD group. An association of polymorphisms in the same gene did not have an additive or synergistic effect, nor did it increase the risk of CAD. Polymorphic associations in different genes increased the risk of CAD, compared with the isolated polymorphisms. The association of ACE DD or ACE 8 GG with PON1 192RR increased the risk of CA fourfold (1.8 to 4.2). After logistic regression analysis, current smoking, family history, fibrinogen, diabetes, and the ACE DD or ACE 8 GG + MTHFR 1298AA and ACE DD or ACE 8 GG + PON1 192RR associations remained in the, model and proved to be independent predictors of CAD. CONCLUSIONS: The association of polymorphisms in the same gene did not increase the risk of the isolated polymorphism. The association of polymorphisms in genes belonging to different enzyme systems was always linked to increased risk compared to the isolated polymorphisms. This study may contribute to a better understanding of overall genetic risk for CAD rather than that associated with each polymorphism in isolation.

Human paraoxonase gene polymorphisms and coronary artery disease risk.

BACKGROUND: Complex diseases such as coronary artery disease (CAD), hypertension and diabetes are usually caused by individual susceptibility to multiple genes, environmental factors, and the interaction between them. The paraoxonase 1 (PON1) enzyme has been implicated in the pathogenesis of atherosclerosis and CAD. Two common polymorphisms in the coding region of the PON1 gene, which lead to a glutamine (Q)/arginine (R) substitution at position 192 and a leucine (L)/methionine (M) substitution at position 55, influence PON1 activity. Studies have investigated the association between these polymorphisms and CAD, but with conflicting results. AIMS: 1) To evaluate the association between PON1 polymorphisms and CAD risk; and 2) to study the interaction between PON1 polymorphisms and others in different candidate genes. METHODS: We evaluated the risk of CAD associated with PON1 Q192R and L55M polymorphisms in 298 CAD patients and 298 healthy individuals. We then evaluated the risk associated with the interaction of the PON1 polymorphisms with ACE DD, ACE 8 GG and MTHFR 1298AA. Finally, using a logistic regression model, we evaluated which variables (genetic, biochemical and environmental) were linked significantly and independently with CAD. RESULTS: We found that the PON1 55MM genotype was more common in the CAD population, but this did not reach statistical significance as a risk factor for CAD, while PON1 192RR presented an 80% higher relative risk compared to the population without this polymorphism. The interaction between PON1 192RR and MTHFR 1298AA, sited in different genes, increased the risk for CAD, compared with the polymorphisms in isolation (OR=2.76; 95% CI=1.20-6.47; p=0.009), as did the association of PON1 192RR with ACE DD, which presented a 337% higher risk compared to the population without this polymorphic association (OR=4.37; 95% CI=1.47-13.87; p=0.002). Similarly, the association between PON1 192RR and ACE 8 GG was linked to an even higher risk (OR=6.23; 95% CI=1.67-27.37; p<0.001). After logistic regression, smoking, family history, fibrinogen, diabetes, Lp(a) and the association of PON1 192RR + ACE 8 GG remained in the regression model and proved to be significant and independent risk factors for CAD. In the regression model the latter association had OR=14.113; p=0.018. CONCLUSION: When analyzed separately, the PON1 192RR genotype presented a relative risk for CAD 80% higher than in the population without this genotype. Its association with other genetic polymorphisms sited in different genes, coding for different enzymes and belonging to different physiological systems, always increased the risk for CAD. After correction for other conventional and biochemical risk factors, the PON1 192RR + ACE 8 GG association remained a significant and independent risk factor for CAD.

[Angiotensin converting enzyme gene polymorphisms and coronary risk in a Portuguese population].

BACKGROUND: A family history of coronary heart disease (CHD) is a strong risk marker for the disease, independently of classical risk factors. It could be decoded by recognizing the polymorphisms associated with increased risk. Renin-angiotensin system genes are candidate genes in CHD and the deletion allele of the angiotensin converting enzyme (ACE) has been reported as deleterious. However, there is disagreement as to the role of the insertion/deletion polymorphism of the ACE gene in coronary risk. AIM: To evaluate whether ACE gene polymorphisms constitute a CHD risk factor. METHODS: We conducted a population-based case-control study of 301 subjects with a history of myocardial infarction or angiographic evidence of coronary heart disease and 510 age- and gender-matched controls, without CHD, living in a region with high CHD mortality rates. Blood samples were taken, DNA extracted and genotypes determined by the polymerase chain reaction (PCR). Amplification products were identified by agarose gel electrophoresis. STATISTICAL ANALYSIS: The Data were evaluated by SPSS for Windows, using the Student's t test, the chi-square test, odds ratios and 95% confidence intervals. RESULTS: The prevalence of the DD, ID and II genotype was 41.2%, 46.3%, 12.5% in the cases and 28.1%, 55.2% and 16.7% in the control group. The frequency of the DD genotype was significantly higher in the cases than in the controls (41.2% vs. 28.1%, odds ratio 1.79, 95% CI 1.31 to 2.4, p < 0.0001). By contrast, the ID and II genotypes' prevalence was higher in the control group (55.2% vs. 46.3%, p = 0.002 and 16.7 vs. 12.5%, p = NS, respectively) compared to the case group. CONCLUSIONS: This study clearly shows that the ACE DD polymorphism is strongly linked to CHD, and if our data are confirmed in a larger population sample, more aggressive vascular prevention could be justified in patients carrying the DD genotype.

Polymorphism of the ACE gene is associated with extent and severity of coronary disease.

BACKGROUND: The progression and extent of coronary heart disease (CHD) are extremely variable and in many instances independent of conventional risk factors. The differences may be partly explained by less favorable genetic polymorphisms that are associated with them. The polymorphisms of the angiotensin I converting enzyme (ACE) gene have been thoroughly evaluated, but the connection between them and the extent of CHD is unknown. AIMS: Our study is aimed at determining whether any or all of the polymorphisms of the ACE gene are markers of the extent and severity of CHD. METHODS: This was a descriptive study of 296 patients with a history of myocardial infarction or with coronary disease confirmed by coronary angiography. The severity of CHD was quantified according to Leaman's score (based on the number of arteries with more than 75% reduction in diameter and the number of affected coronary segments). The ACE genotypes were determined by specific polymerase chain reaction amplification and the segments were subjected to polyacrylamide gel electrophoresis. The mean coronary score and standard deviation of the three polymorphisms were calculated and the values statistically compared using the Student's t test for independent samples. RESULTS: 296 patients with a mean age of 55.103 years, 234 male, were evaluated. CONCLUSION: The study clearly shows that the DD genotype is linked to the extent of CHD, with a high level of significance. If this is confirmed, careful secondary prevention is indicated in patients with this genotype.