Serum alanine aminotransferase level and liver‐related mortality in patients with chronic hepatitis B: A large national cohort study

Background The serum alanine aminotransferase ( ALT ) level has been used to identify at‐risk patients with chronic hepatitis B ( CHB ) who need antiviral therapy. However, the level associated with increased liver‐related mortality requiring active treatment is still unclear. Methods We used a Health Examination Cohort of the National Health Insurance Service of Korea that included approximately 0.5 million individuals aged 40‐79 years. In total, 12 486 patients with CHB and no other concurrent liver disease were enrolled, and patients’ liver‐related mortality, including that owing to liver cancer, was investigated over 9 years. Results The serum ALT level was correlated positively with liver‐related mortality. The rates in men were 0.14, 0.17, 0.24, 0.57, 0.63 and 0.85 per 100 person‐years (%) for serum ALT levels of <20, 20‐29, 30‐39, 40‐49, 50‐79 and ≥80 U/L, respectively, and the corresponding liver‐related mortality rates in women were 0.03%, 0.09%, 0.12%, 0.63%, 0.65% and 0.32%. In patients with ALT levels of 40‐79 U/L, the liver‐related mortality rates were 0.60% in men and 0.64% in women, which were similar to the overall mortality rate of age‐ and sex‐matched subjects without CHB (0.69%). The best cut‐off values for liver‐related mortality prediction were >34 U/L in men and >30 U/L in women. Conclusions The liver‐related mortality rate increased significantly, even in CHB patients with relatively low serum ALT levels. Careful monitoring or earlier antiviral therapy should be considered for patients aged >40 years with serum ALT levels above the upper limit of normal.