Papel da atividade da alanina aminotransferase na doença hepática gordurosa não alcoólica

Abstract

Basis: Nonalcoholic Fatty Liver Disease (NAFLD) is often found and it can result in cirrhosis and its complication when there is a lack of significant alcohol use. Some people affected by NAFLD can present elevated serum levels of alanine aminotransferase (ALT). Although some authors imply such elevation is associated to liver damage, in many cases it remains unclear. Therefore, the purpose of this study was to evaluate the role of alanine aminotransferase activity in NAFLD bearers, by analyzing the association between ALT value and other aspects such as demographics, clinical, laboratorial, presence of metabolic syndrome and primary NAFLD. Methods: Transverse study with prospective inclusion of patients with fatty infiltration of the liver in imaging studies, who were assisted in gastroenterology and hepatology division at João de Barros Barreto Federal University Hospital and Gaspar Viana Clinics Hospital between 2001 and 2005. We excluded in this study the ones with alcohol consumption > 40g/week and the ones with positive serologic markers for hepatitis B and C. We also analyzed sex, age, symptoms, physical examination, laboratory liver tests, lipidic profile and glycemia. NAFLD was classified in primary and secondary. According to ALT values, patients were divided in high normal level and low normal level. For statistics analysis either chi- square (X²) test or Fisher exact were applied. Results: Thirty four patients were studied, most female (73,5%) with the mean age of 52±14,6 years. The symptoms found in 52,9% of patients were abdominal pain (44,1%), weakness (8,82%), anorexia (5,8%) and nausea. Altered physical examination was detected in 69,2% of patients, being painful abdominal palpation and hepatomegaly found in 61,1% and 44,4% respectively. The ALT average was 1,05±0,7 x the higher normal level. Elevated ALT values were found in 41,2 % of cases. 77,4% subjects accomplished criteria for metabolic syndrome. 55,9% presented hypertension, 26,5% diabetes mellitus, 9,1% low glucose tolerance, 78,8% hypertriglyceridemia, 82,8% low normal HDL level and 87% presented waist circumference increased. 85,3% of patients presented primary NAFLD and 14,7% secondary NAFLD. It was not observed any association between these features and the ALT values. However, there was association between high AST levels and high ALT levels ( P<0,001). Conclusion: Most of individuals in this research were female, symptomatic and had altered physical examination. The presence of metabolic syndrome was expressive meaning significant number of patients with primary NAFLD. High ALT levels were found in a considered number of patients; however, most of analyzed factors were not associated to high ALT levels. NAFLD carriers, who presented elevated ALT, also presented elevated AST. Such alterations mean that elevated AST and ALT in NAFLD carriers characterize liver damage.