Identification of risk groups for advanced liver fibrosis in the general population using the Fibrosis-3 index

We conducted a study using the Fibrosis-3 (FIB-3) index, which is the established age-independent index of fibrosis in nonviral liver disease and addresses the limitations of the FIB-4 index in older age group, to assess the liver fibrosis risk among diverse demographic groups in the general population.

We analyzed 31 327 individuals who underwent health examinations between 2013 and 2020 and investigated the distribution of the FIB-3 index by age group. In addition, we examined the age distribution of the FIB-3 index stratified by background factors, such as sex, body mass index (BMI), alcohol consumption habits, and the presence or absence of fatty liver.

In terms of age-specific distribution, the FIB-3 index remained below 1.5 in >90% of cases until the age of 50 years but exceeded 1.5 beyond the age of 50 years, in approximately 30% among those aged 70 years. Notably, the FIB-3 index above 31 years old was significantly higher in men than in women. Among the different BMI categories, individuals with BMI < 18.5 exhibited the highest prevalence of fibrosis. Habitual drinkers had a higher proportion with FIB-3. index ≥1.5, and some had FIB-3 index ≥2.5, raising the suspicion of advanced hepatic fibrosis. No distinct association was identified between the FIB-3 index and the presence of fatty liver.

The FIB-3 index was useful for identifying cases of advancing hepatic fibrosis in a health checkup population. Liver fibrosis progresses with age in the general population, especially among men, those with low BMI, and habitual drinkers.