Estudo da gordura abdominal e esteatose hepática através de exames de imagem em adolescentes normais e obesos

Abstract

BACKGROUND: Obesity has been a worldwide public health problem, with a high prevalence in children and adolescents. Visceral fat is associated with increased metabolic risk and more subject to complications in relation to chronic diseases in adulthood. One of them is the nonalcoholic fatty liver disease alcoholic. Several diagnostic methods have been used to measure visceral fat and liver fat infiltration. MRI is an excellent accuracy in assessing visceral and subcutaneous abdominal fat in studies in adults and children mainly with the use of MRI 1.5T. One of our goals was to evaluate the 3T MRI to measure the visceral and subcutaneous abdominal fat, correlating anthropometric and laboratory values in obese and normal-weight adolescents. Moreover, ultrasound has been used as an evaluation tool of fatty infiltration of the liver. The hepatorenal index has been used in order to objectify the evaluation of steatosis. The aim of our study is to evaluate the hepatorenal index in the same group of adolescents, correlating it with anthropometric and laboratory parameters. MATERIAL AND METHODS: A prospective, observational study. Fifty-seven adolescents were divided into two groups: overweight / obese (24) and normal (33). All patients underwent ultrasonography, magnetic resonance 3T, anthropometric and laboratory tests. The images of US and MRI were analyzed using the ImageJ softwer. All variables were correlated with visceral and subcutaneous fat and the HRI. RESULTS: The results obtained in this study were divided into two articles. The first correlated the area and the percentage of visceral and subcutaneous fat with anthropometric and laboratory values in obese and normal weight. We observed a correlation between waist circumference in both obese and normal weight. In obese, the total cholesterol/HDL, insulin levels and HOMA-IR were positively correlated with visceral fat. In both groups, the positive correlation was also observed at the level of triglycerides. In the second article, the IHR was positively correlated with DBP and AST in obese, and negatively correlated with HDL. In eutrophic, only males was correlated with the HRI. CONCLUSION: both visceral fat and subcutaneous evaluated by MRI 3T as the HRI evaluated by the US, are easily analyzed with computer analysis using the ImageJ softwer. Waist circumference is a good predictor of both abdominal fat in obese as in normal weight. In obese, visceral fat is associated with insulin resistance-related indicators (insulin and HOMA-IR) and dyslipidemia (total cholesterol / HDL). HDL as a protection in the obese. Triglycerides are visceral fat predictors in both obese as in normal weight. The IHR correlates with DBP and ALT in obese, which again have a protective HDL. In eutrophic, the male has a higher positive correlation with hepatorenal index.