Changes in the prevalence of hepatitis B and metabolic abnormalities among young men in Korea.

Changes in the prevalence of disease over time provide valuable information from a public health perspective. We used data from Korea Military Manpower Administration medical examinations for conscription between 2003 and 2019 (n = 5,355,941), which involved young men aged 19 years, to observe changes in liver disease over time at a population level. Trends in the prevalence of hepatitis B surface antigen (HBsAg), elevated alanine aminotransferase (ALT) levels, the fibrosis-4 (FIB-4) index, obesity, and hypertension were assessed. The prevalence of HBsAg steadily decreased from 3.19% for men born in 1984 to 0.18% for men born in 2000. Among HBsAg-negative subjects, the prevalence of elevated ALT levels increased from 13.15% for men born in 1986 to 16.48% for men born in 2000. The prevalence of obesity, hypertension and the proportion with high FIB-4 scores (≥ 1.45) also increased. This population-based nationwide analysis showed a decreasing trend of HBsAg and increasing trends of possible non-alcoholic fatty liver disease.