Prevalence and factors associated with the presence of nonalcoholic fatty liver disease in an adult population in Spain.

BACKGROUND/AIMS: The prevalence of nonalcoholic fatty liver disease (NAFLD) is unknown in Spain. The purpose of detecting NAFLD patients is to determine the associated factors and prevent its evolution to more severe forms. The aim of this study is to determine the prevalence and factors associated with NAFLD. METHODS: This is a multicentre, cross-sectional, populational study. Individuals between 15 and 85 years of age were randomly selected from 25 primary healthcare centres in the province of Barcelona, Spain. Clinical histories were reviewed, and anamnesis, physical examination, blood analysis and hepatic echography were performed. Individuals with an alcohol intake greater than 30 g/day in men and greater than 20 g/day in women or with known liver disease were excluded. RESULTS: Seven hundred and sixty-six individuals with a mean age of 53+/-14 years (range 17-83, 42.2% men) were included in the study. One hundred and ninety-eight individuals presented NAFLD with echographic criteria (prevalence 25.8, 33.4% men and 20.3% women P<0.001). On multivariate analysis, the following were associated with NAFLD: male sex [odds ratio (OR): 2.34, 95% confidence interval (95% CI): 1.57-3.49], age (OR: 1.04 per year, 95% CI: 1.02-1.05), metabolic syndrome (OR: 2.19, 95% CI: 1.29-3.72), insulin resistance (OR: 6.00, 95% CI: 3.43-10.5) and alanine aminotransferase (OR: 4.21, 95% CI: 2.23-7.95). Of the individuals who consumed alcohol, 29.4% consumed alcohol within the inclusion criteria, with a mean of 9.17+/-6.75 standard beverage units per week. Moderate alcohol intake was not related to NAFLD, although a possible protector effect was found with the quantity consumed among the drinkers who did not consume excessive amounts of alcohol (OR: 0.93 per standard beverage units, 95% CI: 0.88-0.98). CONCLUSION: NAFLD prevalence in our population is very high. Male sex, age, metabolic syndrome, insulin resistance and alanine aminotransferase are the factors associated with NAFLD. Furthermore, studies should be carried out with respect to the controversial effect of alcohol on NAFLD.

Prevalence and factors associated with the presence of non alcoholic fatty liver disease in an apparently healthy adult population in primary care units.

BACKGROUND: Fatty liver disease is characterized by the accumulation of fat vacuoles inside of the hepatocytes. Non alcoholic fatty liver is associated with obesity, type 2 diabetes, dyslipemia, the intake of certain drugs and with the so-called metabolic syndrome. However, there is little information on the clinical relevance of this disorder as a healthcare problem in the general population, since the studies published generally include a limited number of patients and the diagnosis is established on the basis of clear biochemical alterations and liver biopsy. METHODS/DESIGN: The aim of the study is the prevalence of non-alcoholic fatty liver disease in a general adult population by hepatic ultrasonography.A population-based, descriptive, transversal, multicentre study. Eighteen primary care centres of the north of Barcelona and the Maresme Areas of Healthcare Management attending an urban and semi-urban population of 360.000 inhabitants.A randomized sample of 786 subjects of 15 years or older were selected from the population and assigned to the participating centres according to the Primary Care Information System (SIAP): This population is practically the same as the general population of the area. The following determinations will be carried out in all the participants: hepatic ultrasonography to detect fatty liver, a questionnaire concerning liver diseases, alcohol intake, smoking and drug use, physical examination including abdominal perimeter and body mass index and biochemical analysis including liver function tests and parameters related to the metabolic syndrome and the HAIR score. Ultrasonographic diagnosis of fatty liver will be made according to established criteria (American Gastroenterology Association) and diagnosis of metabolic syndrome according to the criteria of the European Group for the Study of Insulin Resistance. DISCUSSION: This study will attempt to determine the prevalence of non alcoholic fatty liver disease, as well as, the factors most frequently associated with the presence of this disease to thereby achieve the most appropriate treatment and avoid the evolution of the disease.