Acurácia da ultrassonografia, utilizando a técnica computadorizada, na avaliação da doença hepática gordurosa não-alcoólica, em adolescentes obesos e eutróficos, comparativamente com a RMN e correlação com exames laboratoriais

• Autor(a) principal: Nascimento, José Hermes Ribas do
• Data de Publicação: 2012
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da PUC_RS
• Texto Completo: http://tede2.pucrs.br/tede2/handle/tede/1406
• topic: MEDICINA; PEDIATRIA; FÍGADO GORDUROSO; FÍGADO - DOENÇAS; ULTRASSONOGRAFIA; DIAGNÓSTICO; OBESIDADE; ADOLESCENTES; CNPQ::CIENCIAS DA SAUDE::MEDICINA

Purpose : Evaluate the accuracy of ultrasonography by using computerized analysis in the NAFLD (NonAlcoholic Fatty Liver Disease) in obese and eutrophic adolescents: correlation with MR and laboratorial exams. Method : The prospective cross-sectional study evaluated fifty adolescents (from 11 to 17 years old) being 24 obese and 26 eutrophic ones. The adolescents were submitted to US exams with computerized analysis, MR, laboratorial exams and anthropometric evaluation. Sensibility, specificity, positive and negative predictive values and accuracy were calculated following ROC curve and area calculation under the established curve to determine the best Ultrasonographic Hepatorenal Gradient (UHRG) to predict steatosis using MR results as gold standard. Insulin, fibrinogen, alkalyne phosphatase (AF), triglycerides, GT Gama, aminotransferases, C-reactive protein (CRP) and HOMA-IR (homeostatic model assessment of insulin resistance índex) measures were analyzed and distributed through a long right (+) caudal curve. Non parametric tests were used in the analysis related to these variables. Results : In the obese group 29.2% were girls and 70.8% were boys and in the eutrophic group 69.2% were girls and 30.8% were boys. The obeseand eutrophic age range was 14.2 years old (±2;11-17 years old) and 14,7 (±2;12-17anos), respectively. The eutrophic patients with steatosis represented 19,2% and the obese ones represented 83% with steatosis. The prevalence of steatosis in the obese patients was significantly higher (83.3%; IC 95% : 64.5%) than in the eutrophic ones (19.2%; IC 95% : 7.4% -37.6%). After the analysis of the UHRG, calculated through the difference in ecogenicity between liver cortical and the liver parenchyma echogenicity a significant difference was revealed among the mean obese and eutrophic adolescents (mean = 19.5; P25=15.5; P75=28 vs mean: 10.0; P25=8; P75=11; p<0,001). A significant difference was also observed between adolescent with and without steatosis (median=22; P25=18.5; P75=29.5 vs median=9; P25=7,8; P75=10; p<0,001). The ROC curve generated for the UHRV estimated a cutoff point 13 and sensibility and specificity estimated in 100%. Considering the same cutoff point for the eutrophic, 9.5% false positives would be estimated (specificity =90.5%) and 0% false negatives (sensibility = 100%). The obese adolescents presented higher laboratorial values when compared with the eutrophic ones with the exception of cholesterol HDL (p<0,001). The adolescents with NAFLD presented higher lab values than the adolescents without NAFLD. In the multi varied analysis only the HOMA-IR poses a risk factor regardless of NAFLD. Conclusões : Sendo o US com a análise computadorizada e o cálculo do GHRU uma técnica simples para avaliação quantitativa da ecogenicidade hepática e não invasiva, o presente estudo sugere que esse procedimento pode tornar-se importante no seguimento de adolescentes obesos e eutróficos com DHGNA. Esse método poderá, ainda, servir no rastreamento populacional da DHGNA e em estudos clínicos. Conclusions : Being the ultrasonography with computerized analysis and hepatorenal gradient a simple quantitative noninvasive technique for hepato echogenicity, it can be of great support in the follow-up of obese and eutrophic adolescents with NAFLD. Such method can be useful to trace population with NAFLD and also for clinical studies.