Dieta com redução de carboidratos para o tratamento da doença hepática gordurosa não alcoólica

Abstract

The nonalcoholic fatty liver disease (NAFLD) is a clinical condition often asymptomatic, caused by fat accumulation in the liver, exceeding about 5% to 10% of body weight, unrelated to alcohol abuse. It is estimated that in developed countries the prevalence varies from 1% to 30% of adults. In Brazil, it is not known what the actual prevalence of the disease. NAFLD is associated with chronic diseases such as obesity, dyslipidemia, metabolic syndrome and insulin resistance; the latter appears in about 75% of individuals with this disease. Although it is not known exactly what the triggering mechanism of the disease, the accepted theory is the "two-hit", ie, it is believed that the onset and aggravation of the disease occurs in two stages. The first "hit" would be the accumulation of fat in the liver parenchyma and the second "hit" would constitute aggression caused by lipopolysaccharide, viruses or alcohol, which leads to oxidative stress, oxidative degradation of lipids and release of inflammatory cytokines, which cause cell damage, inflammation and fibrosis. This thesis is divided into two parts: the first is a chapter of narrative review, entitled: non-alcoholic fatty liver disease: etiology, progression, diagnosis and treatment, which addresses the main findings of NAFLD in our way. The second part is an original article of a systematic review and meta-analysis of five randomized clinical trials, whose objective was to evaluate the effects of a diet low in carbohydrates on blood levels of liver enzymes ALT and AST, as the primary outcome of individuals with NAFLD compared to those submitted to a diet without reducing carbohydrates. In the secondary outcomes was investigated improvement of body weight, serum lipid profile (total cholesterol, triglycerides, HDL-C) and glucose. The results showed no significant differences between the intervention and control groups for all variables. Although realize the need of studies involving more restrictive diets, therefore, most likely to induce more robust benefits and evidence plasma improvement of aminotransferases in the context of NAFLD, the meta-analysis carried out here showed that there is no evidence available to suggest one beneficial effect of diets low in carbohydrates in treating the disease, taking as reference serum aminotransferase levels.