Prevalence of nonalcoholic fatty liver disease in subjects with metabolic syndrome.

Background: Nonalcoholic fatty liver disease (NAFLD) is the main cause of chronic liver disease. Metabolic syndrome (MetS) is an important predictor of NAFLD. Due to the increase of MetS in Mexico, a population-based cross-sectional study was conducted to estimate the prevalence of NAFLD.

Methods: One hundred ninety eight subjects with MetS were randomly selected from 1006 subjects and were invited to participate in the estimation of the prevalence of NAFLD. MetS was diagnosed following the criteria of the National Cholesterol Education Program (ATPIII-NCEP). Abdominal ultrasound was performed and left, right and caudate lobes were assessed according to size, echogenicity and hepatic borders. NAFLD was classified as mild, moderate and severe according to its echogenicity and visualization of the diaphragm and intrahepatic vessel borders. Prevalence of NAFLD was estimated with 95% confidence intervals (95% CI).

Results: Included in the study were 122 males (63.2%) and 71 females (36.8%). Prevalence of NAFLD was 82.9% (95% CI 77.6-88.2%). Prevalence was higher in males (p = 86.9%; 95% CI 80.9-92.9%) than in females (p = 76.1%; 95% CI 66.1-86.0%). There were no age differences. A higher proportion of patients had mild (52.3%) or moderate (22.3%) NAFLD and in only 16 patients was NAFLD severe (8.3%).

Conclusions: The observed prevalence is alarming because 8/10 subjects with MetS had NAFLD in any stage. Health-related measures oriented to decrease the incidence of the MetS will have a favorable impact on the occurrence of NAFLD.