[Risk factors associated with non-alcoholic fatty liver disease: a case-control study]. / Factores de riesgo asociados a la presencia de hígado graso no alcohólico: un estudio de casos y controles.

BACKGROUND AND OBJECTIVES: To establish the factors associated with the presence of non-alcoholic fatty liver disease (NAFLD) and evaluate the influence of each component constituting the metabolic syndrome (MS) and the risk of developing NAFLD. PATIENTS AND METHODS: We performed a multicenter, population-based, observational, analytical study of cases and controls. A case was defined as any patient fulfilling the inclusion criteria and presenting NAFLD by abdominal echography for any reason. A control was randomly selected for each case, from the same health center and of the same age and sex. All the cases underwent anamnesis, physical examination, complete biochemical analyses and determination of MS according to the National Cholesterol Education Program-Adult Treatment Panel III criteria. All the controls also underwent an abdominal echography. RESULTS: We included 327 cases and 377 controls with a mean age of 56 ± 12 years for the cases and of 55 ± 13 years for the controls (range: 17 and 80 years); 52.0% of the cases were males and 49.1% of males were controls. The risk factors associated with NAFLD were obesity (odds ratio [OR] 3.82, 95% confidence interval [95% CI] 2.19-6.66), MS (OR 1.73, 95% CI 1.09-2.75), insulin resistance (OR 3.65, 95% CI 2.18-6.12), and an increase in alanine aminotransferase (ALT) (OR 4.72, 95% CI 2.58-8.61) and gamma glutamyl transferase values (GGT) (OR 1.95, 95% CI 1.14-3.34). The components of the MS best predicting NAFLD were hyperglycemia (OR 1.65, 95% CI1.06-2.56) and triglyceride values (OR 1.75, 95% CI1.13-2.72). CONCLUSIONS: The independent variables associated with NAFLD were obesity, insulin resistance and elevated ALT and GGT. The components of MS best predicting NAFLD were hyperglycemia and an increase in triglyceride values.

Metabolic syndrome and nonalcoholic fatty liver disease in a Spanish population: influence of the diagnostic criteria used.

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is highly prevalent and it is considered the hepatic component of the metabolic syndrome (MetS). The WHO, the National Cholesterol Education Program (NCEP) and the International Diabetes Federation (IDF) have different criteria to define MetS. The aim of this study was to analyze the association between NAFLD and MetS using the three existing criteria. METHODS: Cross-sectional, descriptive population-based study derived from a previous study on the prevalence and factors associated with NAFLD in Spain. RESULTS: A total of 696 individuals [mean age 53 ± 14 years (range 17-83 years)] were included, 59% of whom were women. The prevalence of MetS was 34.2% according to the IDF, 17.7% according to the NCEP and 15.5% according to the WHO. Concordance among the different criteria was between 76 and 87%, with kappa indexes between 0.39 and 0.54. NAFLD was present in 184 individuals according to echographic criteria (prevalence 26.4%). The prevalence of NAFLD among patients with MetS was 43% (IDF), 53% (NCEP) and 64% (WHO). The odds ratio (95% confidence interval) for a logistic regression using NAFLD as a dependent variable varied from 3.44 (2.42-4.88) for IDF to 7.28 (4.68-11.3) for WHO, being 4.28 (2.84-6.43) for NCEP. CONCLUSION: The MetS is quite frequent in the general population, although its prevalence varies considerably according to the criteria used for its definition. The MetS is associated with NAFLD, with the WHO definition being the best to determine its presence, probably because of the inclusion of insulin resistance as a main component. Unification of criteria is needed to adequately compare the prevalence of MetS and its relationship with NAFLD in different population groups.

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.