Prevalence and risk factors of fatty liver in Portuguese adults

Background: Prevalence of fatty liver (FL) and nonalcoholic fatty liver disease (NAFLD) depends mainly on obesity, diabetes and genetic factors. FL and NAFLD prevalence was evaluated in Portuguese adult population and correlated with several risk factors and related mortality data, within the same period. Materials and methods: A cross-sectional, population-based multicenter study, voluntary and randomly selected in 834 Portuguese adults (18-79 years). Participants were evaluated after 12-hour fasting. Anthropometric data, past history including alcohol consumption, and associated diseases were registered. Blood samples were collected for biochemical testing. Dietary intake was evaluated using a semi-quantitative food frequency questionnaire. Presence of FL was evaluated using ultrasound, and NAFLD was diagnosed after exclusion of other causes for liver disease. Results: Adjusted prevalence of FL and NAFLD was 37.8% and 17.0%, respectively. FL individuals were older, more frequently males, with increased probability of having obesity, diabetes or harmful alcohol consumption (HAC). NAFLD individuals were also older, but had a similar sex distribution and an increased probability of obesity and diabetes. In both groups, no differences were found regarding dietary pattern or physical activity. During the same time period, nonalcoholic steatohepatitis (NASH) liver-related deaths in Portugal were 0.105/100 000, while alcohol-related liver disease mortality was 6.790/100 000. Conclusion: The large spectrum of FL was present in more than one third of the population, although only less than half could be classified as NAFLD. Other significant risk factors, such as HAC, are probably implicated in FL, explaining the low NASH-related mortality compared with the high alcohol-related mortality during the same time period.