RAFAEL DE OLIVEIRA ALVIM
Projetos de Pesquisa
Unidades Organizacionais
LIM/13 - Laboratório de Genética e Cardiologia Molecular, Hospital das Clínicas, Faculdade de Medicina
25 resultados
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Agora exibindo 1 - 10 de 25
- BDKRB2+9/-9 Polymorphism Is Associated with Higher Risk for Diabetes Mellitus in the Brazilian General Population(2012) ALVIM, Rafael de Oliveira; SANTOS, Paulo C. J. L.; NASCIMENTO, Raimundo M.; COELHO, George L. L. M.; MILL, Jose G.; KRIEGER, Jose E.; PEREIRA, Alexandre C.Some mechanisms have been proposed to explain the role of bradykinin on glucose homeostasis and some studies reported that the BDKRB2 +9/-9 polymorphism was associated to the transcriptional activity of the receptor. In this scenario, the main aim of this study was to evaluate the association of the BDKRB2 +9/-9 polymorphism with diabetes mellitus risk in the Brazilian general population. This study included 1,032 subjects of the general urban population. Anthropometrical, blood pressure, biochemical, and genotype analyses for the BDKRB2 +9/-9 bp insertion/deletion polymorphism were performed. Individuals carrying +9/+9 or +9/-9 genotypes had higher glucose values (84.5 mg/dL versus 80.6 mg/dL, resp.) and higher frequency of diabetes mellitus (7.6% versus 3.6%, resp.) compared to individuals carrying -9/-9, adjusting for age and gender. In addition, higher diabetes mellitus risk was associated to presence of the +9/+9 or +9/-9 genotypes (OR = 1.91; 95% CI = 1.09-4.19; P = 0.03). Our data suggest that the BDKRB2 +9/-9 polymorphism may act as a genetic modulator of glucose homeostasis. It was previously associated to insulin sensitivity, glucose uptake, and insulin secretion, and, in this study, data suggest that the polymorphism may increase susceptibility to chronic metabolic conditions such as diabetes in the Brazilian population.
- Impact of diabetes mellitus on arterial stiffness in a representative sample of an urban Brazilian population(2013) ALVIM, Rafael de Oliveira; SANTOS, Paulo Caleb Junior Lima; MUSSO, Mariane Manso; CUNHA, Roberto de Sa; KRIEGER, Jose Eduardo; MILL, Jose Geraldo; PEREIRA, Alexandre CostaBackground: Independent of other cardiovascular (CV) risk factors, increased arterial stiffness has been established as a predictor of morbidity and mortality. The main aim of this study was to investigate the impact of diabetes on arterial stiffness in a representative sample of an urban Brazilian population plus Amerindians. Methods: A total of 1,415 individuals from the general population were randomly selected plus 588 Amerindians from a native community in Brazil. In addition, a sub-sample of 380 individuals from the general population had 5-year follow-up data. Pulse wave velocity (PWV) was measured with a non-invasive automatic device (Complior, Colson; Garges les Gonesses, France) and increased arterial stiffness was defined as PWV >= 12 m/s. Results: In the overall group, diabetic individuals had higher frequencies of increased arterial stiffness and hypertension. They also had higher values of PWV, body mass index, total cholesterol, triglycerides, systolic and diastolic blood pressures compared to non-diabetic individuals (p < 0.01). In an analysis stratified by hypertension, PWV values and increased arterial stiffness frequency were higher in diabetic individuals in both groups (hypertensive and non-hypertensive) (p < 0.05). Furthermore, higher risk for increased arterial stiffness was observed in the diabetic individuals from the overall group (OR = 2.27; CI = 1.47-3.52, p < 0.001) and from the hypertensive group (OR = 2.70; CI = 1.58-4.75, p < 0.001), adjusted for covariates. Regarding the ethnic stratification, diabetic individuals from Amerindian, White, and Mulatto (mixed-race) groups had higher PWV values and a greater frequency of increased arterial stiffness compared to non-diabetic individuals. Both diabetic and non-diabetic individuals had higher PWV values after 5 years. There was no significant difference in the 5-year PWV progression in diabetic compared to non-diabetic individuals. Conclusions: These results confirm, in a sample of Brazilian population, that the presence of diabetes is associated with increased arterial stiffness and it may contribute in part to increased cardiovascular risk in diabetic patients.
- Ethnicity and Arterial Stiffness in Brazil(2011) SANTOS, Paulo Caleb Junior de Lima; ALVIM, Rafael de Oliveira; FERREIRA, Noely Evangelista; CUNHA, Roberto de Sa; KRIEGER, Jose Eduardo; MILL, Jose Geraldo; PEREIRA, Alexandre CostaBACKGROUND The impact of increased central arterial stiffness as a predictor of morbidity and mortality, independently of other cardiovascular (CV) risk factors, has been established. The main aim of the present work was to investigate the association of ethnicity on arterial stiffness in different ethnic groups from the Brazilian population. METHODS A total of 1,427 individuals from the general population were randomly selected from the Vitoria City metropolitan area and 588 Amerindians from a native community in Brazil. The ethnicity of the general population was classified by a standard questionnaire as Caucasian descent, African descent, or Mulattos (considered racially mixed subjects). Pulse wave velocity (PWV) was measured with a noninvasive automatic device (Complior, Colson; Garges les Gonesses, France). RESULTS Hemodynamic data of PWV, systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean blood pressure (MBP) was higher in African descent individuals than in the other groups (P < 0.001). These results were still observed after adjustment for age and mean arterial pressure (P < 0.001). In addition, studying only normotensive individuals, PWV adjusted levels were higher in African descent individuals, and lower in Amerindians when compared with other ethnic groups (P < 0.01), showing, without the possible confounder effects of time and severity of hypertension or medication use, that PWV is associated with ethnicity in our population. CONCLUSION The study of different ethnic groups from a highly admixtured population was able to demonstrate an association between ethnicity and arterial stiffness.
- Thioredoxin interacting protein (TXNIP) rs7212 polymorphism is associated with arterial stiffness in the Brazilian general population(2012) ALVIM, R. O.; SANTOS, P. C. J. L.; FERREIRA, N. E.; MILL, J. G.; KRIEGER, J. E.; PEREIRA, A. C.Thioredoxin interacting protein plays a pivotal role in several important processes of cardiovascular homeostasis by functioning as a biological sensor for biomechanical and oxidative stress. However, the effects of genetic variants in the modulation of arterial stiffness are unknown. In this scenario, the present study evaluated the relationship between the TXNIP rs7212 polymorphism and arterial stiffness. In the overall sample and in the diabetic group, individuals carrying CG + GG genotypes had higher PWV values compared with CC genotype group ( 10.0 vs 9.8 ms(-1), P = 0.03; 12.3 vs 11.2 ms(-1), P = 0.01; respectively). Our findings indicated that the G allele may contribute to increased arterial stiffness in the Brazilian general population and suggest a possible interaction with diabetes.
- Heritability of arterial stiffness in a Brazilian population: Baependi Heart Study(2017) ALVIM, Rafael O.; HORIMOTO, Andrea R. V. R.; OLIVEIRA, Camila M.; BORTOLOTTO, Luiz A.; KRIEGER, Jose E.; PEREIRA, Alexandre C.Background: Increased arterial stiffness is an important determinant of cardiovascular disease risk. In addition, it has been recognized that arterial stiffness has familial aggregation; however, there are no studies involving Brazilian families. Thus, the aim of this study was to evaluate the heritability of arterial stiffness in a Brazilian population. Methods: In this study, 1675 eligible individuals (both sexes and aged 18-102 years) were distributed in 125 families resident in the municipality of Baependi, a city located in the southeast of Brazil. Carotid-femoral pulse wave velocity (PWV) was measured with a noninvasive automatic device (Complior; Artech Medical, Pantin, France). Variance component approaches, implemented in the SOLAR computer package (San Antonio, Texas, USA), were applied to estimate the heritability of the studied phenotype under different statistical models. Results: Heritability estimates for carotid-femoral PWV stratified by age ranging from 11 to 35% (higher in individuals aged <= 45 years and lower in individuals aged 18-102 years). Age and hypertension showed significant effects on the PWV trait and significantly affect heritability estimates in all models. Conclusion: We conclude that the heritability of carotid-femoral PWV in a Brazilian population is intermediate, and therefore genetic studies evolving arterial stiffness phenotypes should be encouraged.
- Association between anthropometric indicators of adiposity and hypertension in a Brazilian population: Baependi Heart Study(2017) OLIVEIRA, Camila Maciel de; ULBRICH, Anderson Zampier; NEVES, Felipe Silva; DIAS, Fernando Augusto Lavezzo; HORIMOTO, Andrea Roseli Vancan Russo; KRIEGER, Jose Eduardo; ALVIM, Rafael de Oliveira; PEREIRA, Alexandre da CostaBackground Recently, some studies have evaluated the role of adiposity measures in the prediction of hypertension risk, but the results are conflicting. Thus, the aim of this study was to compare which of the four indicators of adiposity (waist circumference-WC, body mass index-BMI, body adiposity index-BAI, and visceral adiposity index-VAI) were better associated with hypertension in a Brazilian population. Methods and findings For this study, were selected 1627 individuals(both genders, and aged over 18 years) resident in the municipality of Baependi, a city located in the Southeast of Brazil. WC, BMI, BAI and VAI were determined according to a standard protocol. Hypertension was defined as mean systolic blood pressure >= 140 mmHg and/or diastolic blood pressure >= 90 mmHg, and/or antihypertensive drug use. The indicators of adiposity WC, BMI, BAI, and VAI were higher in hypertensive when compared to non-hypertensive individuals. In addition, WC and BMI were most strongly associated with hypertension in men and women, respectively. The area under the curve (AUC) of WC was significantly higher than VAI in men. In women, both AUC of BMI and WC showed higher discriminatory power to predict hypertension than BAI and VAI. Conclusions The indicators of adiposity WC and BMI were better associated with hypertension than BAI and VAI, in both genders, and it could be a useful tools for the screening of hypertensive patients.
- Arterial Stiffness: Pathophysiological and Genetic Aspects(2017) ALVIM, Rafael de Oliveira; SANTOS, Paulo Caleb Junior Lima; BORTOLOTTO, Luiz Aparecido; MILL, José Geraldo; PEREIRA, Alexandre da CostaAbstract Cardiovascular diseases (CVD) are the main cause of mortality and it represents a significant percentage of hospitalizations. In the scenario of minimization of costs of the health system, methods that identify subclinical CVD would be important. Some guidelines include the measures of aortic stiffness and intima-media thickness of the carotid artery as methods to identify subclinical CVD in hypertensive patients. The pulse wave velocity (PWV) is the gold standard for the evaluation of arterial stiffness. In this review, we report the pathophysiology, the determinants of arterial stiffness, and justify its inclusion in the assessment of hypertensive patient due its direct association with cardiovascular risk, as show in the I Diretriz Brasileira de Prevenção Cardiovascular. In addition, we raised the main genetic studies of this phenotype, due to its complexity, can be modulated by dozens of genes. However, a better understanding of the relationship genetic-arterial stiffness and, even an intervention based on genotypes, should be achieved in future studies.
conferenceObject Heritability and correlation map of skin viscoelastic measurements with environmental and life style factors of Brazilian population(2015) AZAMBUJA, A. P.; NAKAMURA, M. S.; PIRES, T. F.; HORIMOTO, A. R.; ALVIM, R.; KRIEGER, J. E.; PEREIRA, A. C.- Association between the C242T polymorphism in the p22phox gene with arterial stiffness in the Brazilian population(2012) ALVIM, Rafael de Oliveira; SANTOS, Paulo Caleb Junior Lima; DIAS, Rodrigo Goncalves; RODRIGUES, Mariliza Velho; CUNHA, Roberto de Sa; MILL, Jose Geraldo; NADRUZ JUNIOR, Wilson; KRIEGER, Jose Eduardo; PEREIRA, Alexandre CostaAssociation between the C242T polymorphism in the p22phox gene with arterial stiffness in the Brazilian population. Physiol Genomics 44: 587-592, 2012. First published April 10, 2012; doi:10.1152/physiolgenomics.00122.2011.-NADPH oxidase p22phox subunit is responsible for the production of reactive oxygen species in the vascular tissue. The C242T polymorphism in the p22phox gene has been associated with diverse coronary artery disease phenotypes, but the findings about the protective or harmful effects of the T allele are still controversial. Our main aim was to assess the effect of p22phox C242T genotypes on arterial stiffness, a predictor of late morbidity and mortality, in individuals from the general population. We randomly selected 1,178 individuals from the general population of Vitoria City, Brazil. Genotypes for the C242T polymorphism were detected by PCR-RFLP, and pulse wave velocity (PWV) values were measured with a noninvasive automatic device Complior. p22phox and TNF-alpha gene expression were quantified by real-time PCR in human arterial mammary smooth muscle cells. In both the entire and nonhypertensive groups: individuals carrying the TT genotype had higher PWV values and higher risk for increased arterial stiffness [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.27-2.92 and OR 1.78, 95% CI 1.07-2.95, respectively] compared with individuals carrying CC + CT genotypes, even after adjustment for covariates. No difference in the p22phox gene expression according C242T genotypes was observed. However, TNF-alpha gene expression was higher in cells from individual carrying the T allele, suggesting that this genetic marker is associated with functional phenotypes at the gene expression level. In conclusion, we suggest that p22phox C242T polymorphism is associated with arterial stiffness evaluated by PWV in the general population. This genetic association shed light on the understanding of the genetic modulation on vascular dysfunction mediated by NADPH oxidase.
- A population-based study of the stratum corneum moisture(2016) PIRES, Thiago de Farias; AZAMBUJA, Ana Paula; HORIMOTO, Andrea Roseli Vancan Russo; NAKAMURA, Mary Sanae; ALVIM, Rafael de Oliveira; KRIEGER, Jose Eduardo; PEREIRA, Alexandre CostaBackground: The stratum corneum (SC) has important functions as a bound-water modulator and a primary barrier of the human skin from the external environment. However, no large-epidemiological study has quantified the relative importance of different exposures with regard to these functional properties. In this study, we have studied a large sample of individuals from the Brazilian population in order to understand the different relationships between the properties of SC and a number of demographic and self-perceived variables. Methods: One thousand three hundred and thirty-nine individuals from a rural Brazilian population, who were participants of a family-based study, were submitted to a cross-sectional examination of the SC moisture by capacitance using the Corneometer (R) CM820 and investigated regarding environmental exposures, cosmetic use, and other physiological and epidemiological measurements. Self-perception-scaled questions about skin conditions were also applied. Results: We found significant associations between SC moisture and sex, age, high sun exposure, and sunscreen use frequency (P<0.025). In specific studied sites, self-reported race and obesity were also found to show significant effects. Dry skin self-perception was also found to be highly correlated with the objective measurement of the skin. Other environmental effects on SC moisture are also reported.
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