918 resultados para Risk reduction
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Exercise training has an important role in the prevention and treatment of hypertension, but its effects on the early metabolic and hemodynamic abnormalities observed in normotensive offspring of hypertensive parents (FH+) have not been studied. We compared high-intensity interval (aerobic interval training, AIT) and moderate-intensity continuous exercise training (CMT) with regard to hemodynamic, metabolic and hormonal variables in FH+ subjects. Forty-four healthy FH+ women (25.0+/-4.4 years) randomized to control (ConFH+) or to a three times per week equal-volume AIT (80-90% of VO(2MAX)) or CMT (50-60% of VO(2MAX)) regimen, and 15 healthy women with normotensive parents (ConFH-; 25.3+/-3.1 years) had their hemodynamic, metabolic and hormonal variables analyzed at baseline and after 16 weeks of follow-up. Ambulatorial blood pressure (ABP), glucose and cholesterol levels were similar among all groups, but the FH+ groups showed higher insulin, insulin sensitivity, carotid-femoral pulse wave velocity (PWV), norepinephrine and endothelin-1 (ET-1) levels and lower nitrite/ nitrate (NOx) levels than ConFH- subjects. AIT and CMT were equally effective in improving ABP (P<0.05), insulin and insulin sensitivity (P<0.001); however, AIT was superior in improving cardiorespiratory fitness (15 vs. 8%; P<0.05), PWV (P<0.01), and BP, norepinephrine, ET-1 and NOx response to exercise (P<0.05). Exercise intensity was an important factor in improving cardiorespiratory fitness and reversing hemodynamic, metabolic and hormonal alterations involved in the pathophysiology of hypertension. These findings may have important implications for the exercise training programs used for the prevention of inherited hypertensive disorder. Hypertension Research (2010) 33, 836-843; doi:10.1038/hr.2010.72; published online 7 May 2010
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Background We validated a strategy for diagnosis of coronary artery disease ( CAD) and prediction of cardiac events in high-risk renal transplant candidates ( at least one of the following: age >= 50 years, diabetes, cardiovascular disease). Methods A diagnosis and risk assessment strategy was used in 228 renal transplant candidates to validate an algorithm. Patients underwent dipyridamole myocardial stress testing and coronary angiography and were followed up until death, renal transplantation, or cardiac events. Results The prevalence of CAD was 47%. Stress testing did not detect significant CAD in 1/3 of patients. The sensitivity, specificity, and positive and negative predictive values of the stress test for detecting CAD were 70, 74, 69, and 71%, respectively. CAD, defined by angiography, was associated with increased probability of cardiac events [log-rank: 0.001; hazard ratio: 1.90, 95% confidence interval (CI): 1.29-2.92]. Diabetes (P=0.03; hazard ratio: 1.58, 95% CI: 1.06-2.45) and angiographically defined CAD (P=0.03; hazard ratio: 1.69, 95% CI: 1.08-2.78) were the independent predictors of events. Conclusion The results validate our observations in a smaller number of high-risk transplant candidates and indicate that stress testing is not appropriate for the diagnosis of CAD or prediction of cardiac events in this group of patients. Coronary angiography was correlated with events but, because less than 50% of patients had significant disease, it seems premature to recommend the test to all high-risk renal transplant candidates. The results suggest that angiography is necessary in many high-risk renal transplant candidates and that better noninvasive methods are still lacking to identify with precision patients who will benefit from invasive procedures. Coron Artery Dis 21: 164-167 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.
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Background. We assessed the results of a noninvasive therapeutic strategy on the long-term occurrence of cardiac events and death in a registry of patients with chronic kidney disease (CKD) and coronary artery disease (CAD). Methods. We analyzed 519 patients with CKD (56+/-9 years, 67% men, 67% whites) on maintenance hemodialysis with clinical or scintigraphic evidence of CAD by using coronary angiography. Results. In 230 (44%) patients, coronary angiography revealed significant CAD (lumen reduction >= 70%). Subjects with significant CAD were kept on medical treatment (MT; n=184) or referred for myocardial revascularization (percutaneous transluminal coronary angioplasty/coronary artery bypass graft-intervention; n=30) according to American College of Cardiology/American Heart Association guidelines. In addition, 16 subjects refused intervention and were also followed-up. Event-free survival for patients on MT at 12, 36, and 60 months was 86%, 71%, and 57%, whereas overall survival was 89%, 71%, and 50% in the same period, respectively. Patients who refused intervention had a significantly worse prognosis compared with those who actually underwent intervention (events: hazard ratio=4.50; % confidence interval=1.48-15.10; death: hazard ratio=3.39; % confidence interval 1.41-8.45). Conclusions. In patients with CKD and significant CAD, MT promotes adequate long-term event-free survival. However, failure to perform a coronary intervention when necessary results in an accentuated increased risk of events and death.
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Introduction: Association between ADAMTS13 levels and cardiovascular events has been described recently. However, no genetic study of ADAMTS13 in coronary patients has been described. Materials and Methods: Based on related populations frequencies and functional studies, we tested three ADAMTS13 polymorphisms: C1342G (Q448E), C1852G (P618A) and C2699T (A900V) in a group of 560 patients enrolled in the Medical, Angioplasty, or Surgery Study II (MASS II), a randomized trial comparing treatments for patients with coronary artery disease (CAD) and preserved left ventricular function. The incidence of the 5-year end-points of death and death from cardiac causes, myocardial infarction, refractory angina requiring revascularization and cerebrovascular accident was determined for each polymorphim`s allele, genotype and haplotype. Risk was assessed with the use of logistic regression and Cox proportional-hazards model and multivariable adjustment was employed for possible confounders. Results: Clinical characteristics and received treatment of each genotype group were similar at baseline. In an adjusted model for cardiovascular risk variables, we were able to observe a significant association between ADAMTS13 900V variant and an increased risk of death (OR: 1,92 CI: 1,14-3,23, p = 0,015) or death from cardiac cause (OR: 2,67, CI: 1,59-4,49, p = 0,0009). No association between events and ADAMTS13 Q448E or P618A was observed. Conclusions: This first report studying the association between ADAMTS13 genotypes and cardiovascular events provides evidence for the association between ADAMTS13 900V variant and an increased risk of death in a population with multi-vessel CAD. (C) 2009 Elsevier Ltd. All rights reserved.
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Background: Insulin resistance and obesity are recognized as left ventricular (LV) mass determinants independent of blood pressure (BP). Prevalence of LV hypertrophy (LVH) and the relationship between LV mass to body composition and metabolic variables were evaluated in normotensive individuals as participants of a population-based study. Methods: LV mass was measured using the second harmonic image by M-mode 2D guided echocardiography in 326 normotensive subjects (mean 47 +/- 9.4 years). Fasting serum lipids and glucose, BP, body composition and waist circumference (WC) were recorded during a clinic visit. Results: Applying a normalization criterion not related to body weight (g/height raised to the power 2.7) and the cut-off points of 47.7 (men) and 46.6 g/m(2.7) (women), LVH was found in 7.9% of the sample. Univariate analysis showed LV mass (g/m(2.7)) related to age, body mass index (BMI), WC, fat and lean body mass, systolic and diastolic BP, and metabolic variables (cholesterol, HDL-c, triglycerides and glucose). In multivariate analysis only BMI and age-adjusted systolic BP remained as independent predictors of LV mass, explaining 31% and 5% of its variability. Removing BMI from the model, WC, age-adjusted systolic BP and lean mass remained independent predictors, explaining 25.0%, 4.0% and 1.5% of LV mass variability, respectively. After sex stratification, LV mass predictors were WC (8%) and systolic BP (5%) in men and WC (36%) and systolic BP (3%) in women. Conclusion: BMI in general and particularly increased abdominal adiposity (WC as surrogate) seems to account for most of LV mass increase in normotensive individuals, mainly in women. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Objective: To evaluate physicians` attitudes and adherence to the use of risk scores in the primary prevention of cardiovascular disease (CVD). Design and methods: A cross-sectional survey of 2056 physicians involved in the primary prevention of CVD. Participants included cardiologists (47%), general practitioners (42%), and endocrinologists (11%) from several geographical regions: Brazil (n=968), USA (n=381), Greece (n=275), Chile (n=157), Venezuela (n=128), Portugal (n=42), The Netherlands (n=41), and Central America (Costa Rica, Panama, El Salvador and Guatemala; n=64). Results: The main outcome measure was the percentage of responses on a multiple-choice questionnaire describing a hypothetical asymptomatic patient at intermediate risk for CVD according to the Framingham Risk Score. Only 48% of respondents reported regular use of CVD risk scores to tailor preventive treatment in the case scenario. Of non-users, nearly three-quarters indicated that `It takes up too much of my time` (52%) or `I don`t believe they add value to the clinical evaluation` (21%). Only 56% of respondents indicated that they would prescribe lipid-lowering therapy for the hypothetical intermediate-risk patient. A significantly greater proportion of regular users than non-users of CVD risk scores identified the need for lipid-lowering therapy in the hypothetical patient (59 vs. 41%; p<0.0001).
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Objectives: To analyze the effect of a prevention program oil the estimated cardiovascular risk calculated by three risk scores. Methods: We prospectively evaluated 87 HIV+ patients with elevated cardiovascular risk estimation. Framirigham (FIRS), PROCAM and National Cholesterol Education Program (ATP-III) were applied. Cardiovascular risk was defined as elevated if >10%. All patients received non-pharmacological (diet, exercise, smoking cessation) and, when appropriate, pharmacological therapy. Results: Mean age was 52 years, 92% were male, 39.1% were smokers, 70.1% had hypertension, 18.4% had diabetes. All patients were under HAART, 56.3% were receiving protease inhibitors (131). After 6 months, intervention was associated to significant changes oil triglycerides (298 242 and 206 +/- 135 mg/dL, p<0.05), total-cholesterol (224 +/- 47 and 189 +/- 38 mg/dL, p<0.001). LDL-cholesterol (129 +/- 44 and 109 +/- 30 mg/dL,p<0.001). Frequencies of patients with elevated cardiac risk before and 6 months after intervention were 92% x 27.6% (p < 0.0001), 80.5% x 50.6% (p < 0.0002), and 25.3% x 14.9% (p = 0.12), for FIRS, ATP III and PROCAM, respectively. Conclusions: An intervention Program focused on reduction of traditional risk factors was able to decrease the frequency of patients with HIV infection and elevated cardiovascular risk estimation. FIRS showed greater sensitivity than the other scores. (C) 2008 Elsevier Ireland Ltd. All rights reserved.
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Background: Chagas` disease is the illness caused by the protozoan Trypanosoma cruzi and it is still endemic in Latin America. Heart transplantation is a therapeutic option for patients with end-stage Chagas` cardiomyopathy. Nevertheless, reactivation may occur after transplantation, leading to higher morbidity and graft dysfunction. This study aimed to identify risk factors for Chagas` disease reactivation episodes. Methods: This investigation is a retrospective cohort study of all Chagas` disease heart transplant recipients from September 1985 through September 2004. Clinical, microbiologic and histopathologic data were reviewed. Statistical analysis was performed with SPSS (version 13) software. Results: Sixty-four (21.9%) patients with chronic Chagas` disease underwent heart transplantation during the study period. Seventeen patients (26.5%) had at least one episode of Chagas` disease reactivation, and univariate analysis identified number of rejection episodes (p = 0.013) and development of neoplasms (p = 0.040) as factors associated with Chagas` disease reactivation episodes. Multivariate analysis showed that number of rejection episodes (hazard ratio = 1.31; 95% confidence interval [CI]: 1.06 to 1.62; p = 0.011), neoplasms (hazard ratio = 5.07; 95% CI: 1.49 to 17.20; p = 0.009) and use of mycophenolate mofetil (hazard ratio = 3.14; 95% CI: 1.00 to 9.84; p = 0.049) are independent determinants for reactivation after transplantation. Age (p = 0.88), male gender (p = 0.15), presence of rejection (p = 0.17), cytomegalovirus infection (p = 0.79) and mortality after hospital discharge (p = 0.15) showed no statistically significant difference. Conclusions: Our data suggest that events resulting in greater immunosuppression status contribute to Chagas` disease reactivation episodes after heart transplantation and should alert physicians to make an early diagnosis and perform pre-emptive therapy. Although reactivation led to a high rate of morbidity, a low mortality risk was observed.
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Objectives To compare carotid intima-media thickness (cIMT) of children and adolescents with and without HIV infection and to determine associations among independent socio-demographic, clinical or cardiovascular variables and cIMT in HIV-infected children and adolescents. Patients and methods This is a matched case-control study comparing 83 HIV-infected and 83 healthy children and adolescents. Clinical and laboratorial parameters, cIMT and echocardiogram were measured. Results The cIMT was higher in HIV-infected individuals (median 480 mu m; interquartile range 463-518 mu m) compared with controls (426 mu m; range 415-453 mu m, P < 0.001). In addition, the HIV-infected group showed higher levels of high-sensitive C-reactive protein (medians 1.0 mg/l vs. 0.4 mg/l, P < 0.001), glycated hemoglobin (6.1 +/- 0.9 vs. 5.7 +/- 0.8%, P= 0.028) and triglycerides (medians 0.9 vs. 0.8 mmol/l, P= 0.031). Finally, this group showed lower levels of total and high-density lipoprotein-cholesterol. After multivariate analysis, increased cIMT was positively associated with stavudine use [odds ratio (OR): 18.9, P=0.005], left atrial/aorta index (OR: 15.6, P=0.019), suprailiac skinfold (OR: 7.9, P=0.019), tachypnea (OR: 5.9, P=0.031), CD8 lymphocyte count (OR: 5.7, P=0.033) and CD4 T-lymphocyte count (OR: 5.5, P=0.025). cIMT increment was negatively associated with total cholesterol (OR: 0.2, P=0.025) and with CD8 zenith (OR: 0.1, P=0.007). Conclusion In this sample of children and adolescents, having HIV infection was associated with increased cIMT and elevated prevalence of cardiovascular risk factors. These findings suggest that this group should be included in cardiovascular prevention programs.
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Background: UV radiation is the major environmental factor related to development of cutaneous melanoma. Besides sun exposure and the influence of latitude, some host characteristics such as skin phototype and hair and eye color are also risk factors for melanoma. Polymorphisms in DNA repair genes could be good candidates for susceptibility genes, mainly in geographical regions exposed to high solar radiation. Objective: Evaluate the role of host characteristic.; and DNA repair polymorphism in melanoma risk in Brazil. Methods: We carried out a hospital-based case-control study in Brazil to evaluate the contribution of host factors and polymorphisms in DNA repair to melanoma risk. A total of 412 patients (202 with melanoma and 210 controls) were analyzed regarding host characteristics for melanoma risk as well as for 11 polymorphisms in DNA repair genes. Results: We found an association of host characteristics with melanoma development, such as eye and hair color, fair skin, history of pigmented lesions removed, sunburns in childhood and adolescence, and also European ancestry. Regarding DNA repair gene polymorphisms, we found protection for the XPG 1104 His/His genotype (OR 0.32; 95% CI 0.13-0.75), and increased risk for three polymorphisms in the XPC gene (PAT+; IV-6A and 939Gln), which represent a haplotype for XPC. Melanoma risk was higher in individuals carrying the complete XPC haplotype than each individual polymorphism (OR 3.64; 95% CI 1.77-7.48). Conclusions: Our data indicate that the host factors European ancestry and XPC polymorphisms contributed to melanoma risk in a region exposed to high sun radiation. (C) 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.
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The present study aimed to investigate the presence of corpus callosum (CC) volume deficits in a population-based recent-onset psychosis (ROP) sample, and whether CC volume relates to interhemispheric communication deficits. For this purpose, we used voxel-based morphometry comparisons of magnetic resonance imaging data between ROP (n = 122) and healthy control (n = 94) subjects. Subgroups (38 ROP and 39 controls) were investigated for correlations between CC volumes and performance on the Crossed Finger Localization Test (CFLT). Significant CC volume reductions in ROP subjects versus controls emerged after excluding substance misuse and non-right-handedness. CC reductions retained significance in the schizophrenia subgroup but not in affective psychoses subjects. There were significant positive correlations between CC volumes and CFLT scores in ROP subjects, specifically in subtasks involving interhemispheric communication. From these results, we can conclude that CC volume reductions are present in association with ROP. The relationship between such deficits and CFLT performance suggests that interhemispheric communication impairments are directly linked to CC abnormalities in ROP. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
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OBJECTIVE To examine cortical thickness and volumetric changes in the cortex of patients with polymicrogyria, using an automated image analysis algorithm. METHODS Cortical thickness of patients with polymicrogyria was measured using magnetic resonance imaging (MRI) cortical surface-based analysis and compared with age-and sex-matched healthy subjects. We studied 3 patients with disorder of cortical development (DCD), classified as polymicrogyria, and 15 controls. Two experienced neuroradiologists performed a conventional visual assessment of the MRIs. The same data were analyzed using an automated algorithm for tissue segmentation and classification. Group and individual average maps of cortical thickness differences were produced by cortical surface-based statistical analysis. RESULTS Patients with polymicrogyria showed increased thickness of the cortex in the same areas identified as abnormal by radiologists. We also identified a reduction in the volume and thickness of cortex within additional areas of apparently normal cortex relative to controls. CONCLUSIONS Our findings indicate that there may be regions of reduced cortical thickness, which appear normal from radiological analysis, in the cortex of patients with polymicrogyria. This finding suggests that alterations in neuronal migration may have an impact in the cortical formation of the cortical areas that are visually normal. These areas are associated or occur concurrently with polymicrogyria.
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Experimental data for E. coli debris size reduction during high-pressure homogenisation at 55 MPa are presented. A mathematical model based on grinding theory is developed to describe the data. The model is based on first-order breakage and compensation conditions. It does not require any assumption of a specified distribution for debris size and can be used given information on the initial size distribution of whole cells and the disruption efficiency during homogenisation. The number of homogeniser passes is incorporated into the model and used to describe the size reduction of non-induced stationary and induced E. coil cells during homogenisation. Regressing the results to the model equations gave an excellent fit to experimental data ( > 98.7% of variance explained for both fermentations), confirming the model's potential for predicting size reduction during high-pressure homogenisation. This study provides a means to optimise both homogenisation and disc-stack centrifugation conditions for recombinant product recovery. (C) 1997 Elsevier Science Ltd.
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A series of studies was conducted to compare group differences in the goal orientations of delinquent, at-risk, and not-at-risk adolescents. An Importance of Goals Scale was developed by examining the item responses of 230 high school students and validated by administering the revised scale to 80 delinquent, 90 at-risk, and 90 not-at-risk adolescents. Results identified differences in the importance attributed to different goals by the 3 groups. Delinquent and at-risk adolescents attached significantly more importance to goals associated with developing a social image (e.g., delinquency, freedom-autonomy), whereas not-at-risk adolescents were more concerned with goals associated with an academic image (e.g., educational, interpersonal). Results are discussed in terms of their implications for school achievement, peer relations, and future life paths.
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This paper considers a stochastic frontier production function which has additive, heteroscedastic error structure. The model allows for negative or positive marginal production risks of inputs, as originally proposed by Just and Pope (1978). The technical efficiencies of individual firms in the sample are a function of the levels of the input variables in the stochastic frontier, in addition to the technical inefficiency effects. These are two features of the model which are not exhibited by the commonly used stochastic frontiers with multiplicative error structures, An empirical application is presented using cross-sectional data on Ethiopian peasant farmers. The null hypothesis of no technical inefficiencies of production among these farmers is accepted. Further, the flexible risk models do not fit the data on peasant farmers as well as the traditional stochastic frontier model with multiplicative error structure.