Distribution of FIB-4 index in the general population: analysis of 75,666 residents who underwent health checkups.

BACKGROUND: Fatty liver is frequently found in a general population, and it is critical to detect advanced fibrosis. FIB-4 index is considered a useful marker for evaluating liver fibrosis but the distribution of FIB-4 index in the general population remains unknown. METHODS: This cross-sectional study included residents who underwent ultrasonography at health checkups in Hiroshima or Iwate prefectures. The distribution of FIB-4 index in the total study population (N = 75,666) as well as in non-alcoholic fatty liver disease (NAFLD) populations (N = 17,968) and non-drinkers without fatty liver populations (N = 47,222) was evaluated. The distribution of aspartate aminotransferase (AST) levels, alanine aminotransferase (ALT) levels was also evaluated. RESULTS: The mean FIB-4 index in the total study population was 1.20 ± 0.63. FIB-4 index ≥ 2.67, which indicates a high risk of liver fibrosis, was found in 16.4% of those aged ≥ 70 years. In the NAFLD population, 58.1% of those in their 60 s and 88.1% of those ≥ 70 years met the criteria for referral to hepatologists by using the recommended FIB-4 index cutoff value (≥ 1.3). The mean FIB-4 index in the NAFLD population (1.12 ± 0.58) was significantly lower than in the non-drinkers without fatty liver (1.23 ± 0.63, p < 0.0001). The non-drinkers without fatty liver tended to have higher AST relative to ALT levels (60.0% with AST/ALT > 1.0), whereas the results in the NAFLD population were opposite (14.8% with AST/ALT > 1.0). AST > ALT resulted in a higher FIB-4 index in non-drinkers without fatty liver due to the nature of FIB-4 index formula. CONCLUSIONS: The cutoff value of FIB-4 index (≥ 1.3) for triaging the elderly people with fatty liver for referral to hepatologists should be reconsidered to avoid over-referral. Due to the impact of age and characteristics of AST/ALT ratios, there is no prospect of using FIB-4 index for primary screening for liver fibrosis in a general population of unknown presence or absence of liver disease, even though it can be easily calculated using routine clinical indices. It is desired to develop a non-invasive method for picking up cases with advanced fibrosis latent in the general population.

Relationship between drinking frequency and fatty liver prevalence or incidence in Japanese undergoing health checkup in 2008-2019.

BACKGROUND & AIMS: The relationship between the frequency of drinking and fatty liver in the general population is still poorly understood. This study analysed data from a large cohort who underwent health checkups in Japan between 2008 and 2019 to investigate the prevalence and incidence of fatty liver by alcohol consumption and risk factors for fatty liver. METHODS: The prevalence of fatty liver diagnosed with ultrasonography was calculated in 75,670 residents. The incidence of fatty liver in 31,062 residents who underwent ultrasonography at least twice during the period without fatty liver at the first time was calculated using the person-year method. Multivariate logistic analysis was performed to investigate risk factors associated with the prevalence and incidence of fatty liver. RESULTS: The prevalence of fatty liver was 27.6% (95% confidence interval [CI], 27.2-27.9) in non-drinkers, 28.5% (27.5-29.5) in moderate-drinkers and 28.0% (26.0-29.9) in heavy-drinkers. The incidence of fatty liver was 3,084/100,000 person-years (2,997-3,172/100,000) in non-drinkers, 3,754/100,000 person-years (3,481-4,042/100,000) in moderate-drinkers and 3,861/100,000 person-years (3,295-4,497/100,000) in heavy-drinkers. The prevalence and incidence of fatty liver were not associated with drinking status. Obesity was the most important independent risk factor (prevalence: adjusted odds ratio [AOR], 6.3; 95% CI, 6.0-6.5; incidence: AOR, 2.4; 95% CI, 2.3-2.6). CONCLUSIONS: Drinking status does not affect the prevalence or incidence of fatty liver in Japanese residents undergoing health checkups. From a public health perspective, measures for obesity control must be prioritised to reduce the burden of disease of fatty liver in Japan.