Background: Although most epidemiological studies have been conducted using a relatively small population or subjects who had medical screenings, the present study aimed to investigate the incidence and prevalence of MASLD (formerly NAFLD) in Korea using nationwide registry data provided by the Health Insurance Review and Assessment Service (HIRA).
Methods: Using nationwide medical records provided by HIRA, we analyzed the entire dataset of patients with MASL (KCD10-K76.0) and MASH (KCD10-K75.8) from 2010 to 2021 and calculated the incidence and prevalence by year, age, and gender. The prevalence and incidence rates were calculated by analyzing the HIRA data covering almost the entire population of Korea for 12 years, from 2010 to 2021, with an average population of 50,856,244 during this period. Statistical analyses included calculating confidence intervals using Ulm's formula and conducting sex- and age-specific analyses with a Cochran-Armitage test for trends.
Results: The annual incidence of MASL/MASH increased significantly from 9.71/0.37 in 2010 to 13.95/5.52 per 1000 persons in 2021 (p < 0.01). The annual prevalence of MASL increased from 15.69 in 2010 to 34.23 per 1000 persons in 2021, while the annual prevalence of MASH increased from 0.49 to 9.79 per 1000 persons between 2010 and 2021 (p < 0.01). Regarding the sex-dimorphic feature of MASLD, there was a male predominance in those < 50 years old but a female predominance in those ≥ 50 years old for the incidence and prevalence of MASL and the incidence of MASH.
Conclusion: The incidence of MASL increased by 3% to 4% every year, while the incidence of MASH increased 14.91-fold from 2010 to 2021. The increasing trend is noteworthy compared with previous reports.
Keywords: HIRA records; MASLD; nationwide dataset; potential underestimation of prevalence; sex-specific differences.