Short-term multidisciplinary non-pharmacological intervention is effective in reducing liver fat content assessed non-invasively in patients with nonalcoholic fatty liver disease (NAFLD).

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) ranges from simple steatosis to steatohepatitis, and cirrhosis in patients with alcohol intake less than 20 g/day, and is usually associated with insulin resistance (IR). AIM: Given that no drugs are specifically approved for NAFLD, we tested the efficacy of a non-pharmacological multidisciplinary intervention based on a personalized diet, physical activity and behavior therapy. METHODS: In this open non-randomized study, personalized diet, physical exercise and behaviour therapy for 3 months were prescribed in 12 consecutive patients with NAFLD. Lifestyle, including total caloric intake, physical activity and resting energy expenditure was monitored by a SenseWear Armband. Insulin Resistance (IR) was measured by HOMA and oral glucose insulin sensitivity tests (OGIS); fat liver content was estimated by two different semi-quantitative scores and by the Doppler Power Index (DPI). RESULTS: Data show that the multidisciplinary intervention produced a significant reduction of total caloric intake, a 8% reduction in body weight, a modest increase in daily physical activity, a significant (P<0.001) reduction of aminotransferases and a decrease of total hepatic fat content. CONCLUSIONS: A 3-month multidisciplinary intervention inducing at least 8% of weight loss, improves liver tests and decreases liver fat content.

Influence of lifestyle habits, nutritional status and insulin resistance in NAFLD.

Non alcoholic fatty liver disease (NAFLD) is associated with obesity, diabetes and insulin resistance (IR). The aim of our study was to assess the relationship between IR, anthropometry, lifestyle habits, resting energy expenditure (REE) and degree of fatty liver at ultrasound in 48 overweight patients with NAFLD as compared to 24 controls without fatty liver, matched for age. Nutritional status, alcohol intake and physical activity were assessed by skinfold thickness measurements, a 7-day diary, and SenseWear armband (SWA). REE was assessed by both SWA (REE-SWA) and a Vmax metabolic cart (REE-Vmax). Fatty liver was measured by US and the Doppler Power Index was calculated. IR was assessed using the HOMA index. There was significant correlation between waist circumference, HOMA, Doppler power index and fatty liver grade at US. Multivariate analysis showed that alteration of waist circumference, Doppler power index, and HOMA were the major significant predictors of fatty liver. Our data demonstrated a significant association between NAFLD and central adiposity and IR.

Epidemiology of non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) is rapidly becoming the most common liver disease worldwide. The prevalence of NAFLD in the general population of Western countries is 20-30%. About 2-3% of the general population is estimated to have non-alcoholic steatohepatitis (NASH), which may progress to liver cirrhosis and hepatocarcinoma. As a rule, the prevalence of NAFLD is higher in males and increases with increasing age, and it is influenced by the diagnostic method and the characteristics of the population, especially lifestyle habits. Population-based studies provide better estimates of the prevalence of NAFLD as compared to autoptic and clinical studies, but few such studies have been performed to date. The diagnosis of NAFLD in population studies is usually obtained by ultrasonography, which is known to underestimate the prevalence of fatty liver. The Dallas Heart Study and the Dionysos Study reported that 30% of the adults in the USA and 25% in Italy have NAFLD. In these studies, 79% and 55% of patients with NAFLD had normal aminotransferase levels, showing that liver enzymes are not surrogate markers of NAFLD in the general population. Noninvasive markers such as the fatty liver index obtained from the Dionysos Study may be useful to screen for NAFLD in the general population. The most important risk factors for NAFLD are male gender, age, obesity, insulin resistance and the cardiometabolic alterations that define the metabolic syndrome. The prevalence of NAFLD is 80-90% in obese adults, 30-50% in patients with diabetes and up to 90% in patients with hyperlipidemia. The prevalence of NAFLD among children is 3-10%, rising up to 40-70% among obese children. Moreover, pediatric NAFLD increased from about 3% a decade ago to 5% today, with a male-to-female ratio of 2:1. The incidence and natural history of NAFLD are still not well defined, but it is recognized that the majority of individuals with NAFLD do not develop NASH. The incidence of NAFLD is probably increasing in Western countries, strictly linked to lifestyle habits.

Epidemiology and natural history of non-alcoholic fatty liver disease (NAFLD).

The authors summarize and update the most recent knowledge in the field of prevalence, natural history and incidence of Non Alcoholic Fatty Liver Disease (NAFLD) and Non Alcoholic Steatohepatitis (NASH). These novel diseases, firstly recognized at the beginning of the second millennium, arose suddenly to the attention of the clinicians, because they are the hepatic expression of the "so-called" metabolic syndrome. Due to the epidemic burden of obesity, diabetes, and metabolic diseases, NAFLD and NASH will become soon probably the most common hepatic disease worldwide, and they surely will keep busy our future young hepatologists.