Prevalence and severity of nonalcoholic fatty liver disease by transient elastography: Genetic and metabolic risk factors in a general population

Abstract

Background & AimsThe worldwide spread of obesity is leading to a dramatic increase in the prevalence of nonalcoholic fatty liver disease (NAFLD) and its complications. We aimed to evaluate both prevalence and factors associated with NAFLD in a general population in a Mediterranean area.MethodsResultsWe considered 890 consecutive individuals included in the community-based ABCD (Alimentazione, Benessere Cardiovascolare e Diabete) study (ISRCTN15840340). Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) were measured with FibroScan. Participants were genotyped for PNPLA3 rs738409 and TM6SF2 rs58542926 variants.The prevalence of NAFLD in the cohort was 48%. NAFLD participants exhibited elevated LSM values, suggesting advanced fibrosis (6.5% of cases). Both NAFLD and advanced fibrosis were independently associated with traditional risk factors (NAFLD: age >50years, obesity, hypertension, elevated ALT and low HDL-cholesterol serum concentrations. Advanced fibrosis: IFG/diabetes, elevated ALT serum concentrations). A high prevalence (>60%) of NAFLD was found in obese people, while it varied widely in non-obese people according to the presence of metabolic risk factors. PNPLA3G variant (OR=1.33, 95% C.I.=1.01-1.8; P<.05) was independently associated with NAFLD. Prevalence of advanced fibrosis (high LSM values) ranged from 3.4% (no risk factors) to 60% (presence of all risk factors). TM6SF2 T variant (OR=3.06, 95% C.I.=1.08-8.65, P<.05) was independently associated with advanced fibrosis (high LSM values).ConclusionsIn a cohort of a general population, the prevalence of NAFLD was very high, and among NAFLD patients a significant proportion had advanced fibrosis (high LSM values). Apart from traditional risk factors, genetic factors may have a significant role that needs to be further investigated.