Adolescentes: comportamento e risco cardiovascular / Adolescents: behavior and cardiovascular risk

Contexto: Os benefícios para a saúde decorrentes da prática regular de atividade física estão bem documentados. Entretanto, são raros os estudos associando essa prática ao comportamento sedentário e ao risco cardiovascular em adolescentes. Objetivos: Pretende-se avaliar a prática de atividade física, o comportamento sedentário e a associação com o risco cardiovascular mensurado pelo escore Pathobiological Determinants of Atherosclerosis in Youth (PDAY). Métodos: Estudo transversal desenvolvido nas escolas públicas estaduais de Campina Grande, PB, Brasil, com 576 adolescentes de 15 a 19 anos, incluindo variáveis socioeconômicas, demográficas, de estilo de vida e clínicas. Os dados foram coletados através de formulário validado, antropometria, aferição da pressão arterial e exames laboratoriais. Foram utilizadas medidas descritivas, teste do qui-quadrado de Pearson e regressão logística binomial. Trabalhou-se com o SPSS 22.0 se adotou intervalo de confiança de 95%. Resultados: A idade média foi de 16,8 anos. A maioria dos adolescentes era do sexo feminino (66,8%), não branco (78.7%) e pertencente às classes C, D e (69,1%). Quanto ao sedentarismo e à insuficiência de atividade física, as prevalências foram de 78,1% e 60,2%, respectivamente. De acordo com o escore PDAY, 10,4% dos adolescentes apresentaram alto risco cardiovascular; 31,8% risco intermediário; e 57,8%, risco baixo. Verificou-se que PDAY esteve associado ao sexo e à adiposidade abdominal. Conclusões: Ficou comprovado que adiposidade abdominal e sexo masculino representam importantes fatores de risco cardiovascular em adolescentes. Considerando-se a presença de um fator de risco modificável, medidas preventivas voltadas ao estilo de vida são essenciais

Background: The health benefits of regular physical activity are well documented. However, there are few studies associating this practice with sedentary behavior and cardiovascular risk in adolescents. Objectives: To evaluate physical activity levels and sedentary behavior and their associations with cardiovascular risk using the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) score Methods: A cross-sectional study carried out in state-owned public schools in Campina Grande, PB, Brazil, with 576 adolescents aged 15 to 19 years, investigating socioeconomic; demographic; lifestyle; and clinical variables. Data were collected using a validated form covering anthropometry data; blood pressure measurements; and laboratory tests. Data were analyzed using descriptive statistics, Pearson's chi-square test, and binomial logistic regression using SPSS 22.0 and adopting a 95% confidence interval. Results: Mean age was 16.8 years. The majority of the adolescents were female (66.8%); non-white (78.7%); and belonged to socioeconomic classes C, D and E (69.1%). The prevalence rates of sedentary behavior and physical inactivity were 78.1% and 60.2%, respectively. According to the PDAY score, 10.4% of adolescents were at high cardiovascular risk and 31.8% and 57.8% were at intermediate risk and low risk, respectively. PDAY scores were associated with sex and abdominal adiposity. Conclusions: It was found that abdominal fat and being male were important cardiovascular risk factors in adolescents. Considering that modifiable risk factors were present, preventive measures aimed at lifestyle changes are essential

Immobilization and stabilization of xylanase by multipoint covalent attachment on agarose and on chitosan supports.

Xylanases have important applications in industry. Immobilization and stabilization of enzymes may allow their reuse in many cycles of the reaction, decreasing the process costs. This work proposes the use of a rational approach to obtain immobilized commercial xylanase biocatalysts with optimized features. Xylanase NS50014 from Novozymes was characterized and immobilized on glyoxyl-agarose, agarose-glutaraldehyde, and agarose-amino-epoxy support and on differently activated chitosan supports: glutaraldehyde-chitosan, glyoxyl-chitosan, and epoxy-chitosan. Two different chitosan matrices were tested. The best chitosan derivative was epoxy-chitosan-xylanase, which presented 100% of immobilization yield and 64% of recovered activity. No significant increase on the thermal stability was observed for all the chitosan-enzyme derivatives. Immobilization on glyoxyl-agarose showed low yield immobilization and stabilization degrees of the obtained derivative. The low concentration of lysine groups in the enzyme molecule could explain these poor results. The protein was then chemically modified with ethylenediamine and immobilized on glyoxyl-agarose. The new enzyme derivatives were 40-fold more stable than the soluble, aminated, and dialyzed enzyme (70 degrees C, pH 7), with 100% of immobilization yield. Therefore, the increase of the number of amine groups in the enzyme surface was confirmed to be a good strategy to improve the properties of immobilized xylanase.