Indicadores antropométricos, bioquímicos, de composição corporal e pressão arterial como preditores de risco cardiovascular em adolescentes

• Autor(a) principal: Crizel, Morgana Martins
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2729
• topic: Circunferência da cintura; Índice de massa corporal; Índice de conicidade; Relação cintura/estatura; Risco cardiovascular; Adolescentes; Waist circumference; Body mass index; Conicity index; Waist/height; Cardiovascular risk; Adolescents; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

The present study aimed to evaluate the capability of anthropometric and body composition indicators to predict changes in body fat, cardiovascular risk factors and metabolic syndrome. This research is an epidemiological investigation, based on a crosscutting strategy, conducted at Divisão de Saúde of Universidade Federal de Viçosa (UFV), where were evaluated 172 adolescents of both sexes, with 16 to 19 years old got from a probabilistic student sample of public and private schools in the urban zone of Viçosa /MG. The anthropometric evaluation included wheight, height and waist circumference (WC) values. Based on those values we calculated waist / height ratio (WHR), conicity index (CI) and body mass index (BMI). To determine the percentage of body fat (% BF) we used the tetrapolar bioelectrical impedance analysis (BIA). We acquire arterial pressure using a monitor of automatic inflation (Omron ® HEM-741 Model CINT) and we categorized those values according to the V Brazilian Guidelines on Hypertension (2006). We performed analysis of blood fasting glucose, triglycerides, total cholesterol, HDL, LDL, VLDL, insulin. We calculated the insulin resistance index (HOMA) and we classified them according to the I Prevention Guidelines of Atherosclerosis for Child and Adolescence hood (2005). As criteria for metabolic syndrome we used the International Diabetes Federation parameters (IDF, 2007). This study was approved by the Committee of Ethics and Research for human beings of Universidade Federal de Viçosa. Our results indicate that weight, height, waist circumference, conicity index, percentage of fat-free mass and systolic blood pressure were higher among boys (p <0.01). The percentage of body fat was higher in girls (p <0.01), while BMI, WHR and diastolic blood pressure did not have differences between the sexes. Regarding the blood pressure of the adolescents assessed, it was observed that 8.8% of girls and 35.5% of boys had values at the borderline or higher than that. The metabolic syndrome prevalence in this population was 1.2%, taking as a parameter a boy and a girl who met the criteria proposed by IDF, 2007. Regarding risk factors for metabolic syndrome, 58.6% of boys and 48% of girls had at least one risk factor. The most prevalent biochemical changes are described in descending order as follow: high total cholesterol 59.8% (n = 61) high LDL 33.3% (n = 34), low HDL 16.6% (n = 17), high triglycerides 9 8% (n = 10) in the girls. Among the boys were: low HDL 52.8% (n = 37), high total cholesterol 28.6% (n = 20), high triglycerides 18.6% (n = 13) and high LDL 14.3% (n = 10). The Hyperglycemia was not frequent in this population, and only one girl (0.98%) had blood glucose above 100mg/dL. Moreover, hyperinsulinemia was present in 5.9% (n = 6) of the girls and 1.4% (n = 1) of the boys. These changes were still observed in the eutrophic adolescents suggesting a risk for metabolic syndrome in this group. Insulin resistance obtained by the HOMA-IR was 4.9% (n = 5) for girls and 1.4% (n = 1) for boys. These changes were still observed in eutrophic adolescents suggesting a risk for metabolic syndrome in this group. Insulin resistance obtained by the HOMA-IR was 4.9% (n = 5) for girls and 1.4% (n = 1) for boys. The results show that waist circumference has a good prediction capability for risk factors of metabolic syndrome, especially in females, and the criteria 69 cm was able to identify at least one risk factor for metabolic syndrome in this population. However, although the sensitivity and specificity have been appropriate, it is important to note that the value of sensitivity resulted in low average of 25 to 28.6% false negatives. Thus, it is important to consider that waist circumference provides an estimate of the risk and not diagnosis of excess body fat and its implications for health. The BMI had good predictive ability in girls, inasmuch as it identified changes in triglycerides, insulin, HOMA index and blood pressure. On the other hand, the BMI did not have the same prediction capability for the boys. Considering the ROC curve analysis, the anthropometric indicators, such as WC and WHR were the best predictors of body fat in females. Anthropometric indicators analyzed showed good discriminatory power of change in triglycerides, insulin, HOMA and blood pressure of adolescents, demonstrating that it has practical applicability for predicting cardiovascular risk factors in girls. In boys, only WHR had predictive ability for high LDL. Remember that changes in lifestyle such as healthy eating habits and physical activity are essential to improve the life quality as well as to reduce the impact that chronic diseases cause in spending on public health.