Increasing Prevalence of Steatotic Liver Disease in a Japanese Health Checkup Population, 2004-2022

Steatotic liver disease (SLD) affects more than 30% of the global population; however, trends in its prevalence remain poorly understood. This study aimed to elucidate prevalence trends of metabolic dysfunction-associated steatotic liver disease (MASLD), MASLD with moderate alcohol intake (MetALD), and alcohol-associated liver disease (ALD) in the Japanese general population.

This retrospective study included participants who underwent health checkups between 2004 and 2022 in Gifu, Japan. SLD was defined by liver ultrasonography and categorised as either MASLD, MetALD, or ALD in the total population, as well as in non-obese (body mass index [BMI] ≤ 25 kg/m²), and lean (BMI ≤ 23 kg/m²) subgroups. Annual percent change (APC) in the prevalence of each SLD subtype was analysed using the Joinpoint regression model.

Among 184 463 participants, 49 651 (26.9%) were diagnosed with SLD, including 41 819 (22.7%) with MASLD, 3792 (2.1%) with MetALD, and 2037 (1.1%) with ALD. Over the study period, APC in the total population revealed significant increases in MASLD (APC, 2.02%; 95% confidence interval [CI], 1.46-2.66; p < 0.001) and MetALD (APC, 1.14%; 95% CI, 0.17-2.19; p = 0.026), with similar trends observed in the non-obese and lean subgroups. ALD prevalence increased only in the lean population (APC, 2.87%; 95% CI, 0.33-5.94; p = 0.031).

MASLD and MetALD increased significantly irrespective of body composition, whereas ALD increased in the lean population over the past two decades. These findings highlight a silent rise of SLD in the Japanese general population.