Becoming Physically Active and Risks of Mortality and Liver‐Related Events in Adults With Chronic Hepatitis B: A Nationwide Cohort Study

ABSTRACT Physical activity (PA) confers several health benefits; however, whether increasing PA among physically inactive adults with chronic hepatitis B (CHB) is associated with lower risks of adverse clinical outcomes remains unclear. We used the nationwide Korean National Health Insurance database. We included 318,131 adults with CHB who were physically inactive at the initial health screening (Exam 1) and completed a subsequent screening within 4 years (Exam 2). Among them, 58,703 initiated moderate‐to‐vigorous PA (MVPA), defined as vigorous activity ≥ 20 min/day on ≥ 3 days/week or moderate activity ≥ 30 min/day on ≥ 5 days/week. The primary outcome was all‐cause mortality, and the secondary outcomes were liver‐related events (hepatic decompensation, liver transplantation, hepatocellular carcinoma [HCC]) and HCC. Multivariable Cox and Fine–Grey competing‐risk models were adjusted for demographic, clinical, and behavioural factors. During a median 7.9‐year follow‐up (IQR, 5.2–9.5), 7609 deaths occurred. MVPA initiation was associated with lower all‐cause mortality (hazard ratio [HR], 0.89; 95% CI, 0.84–0.94), a lower risk of liver‐related events (subdistribution HR [subHR], 0.94; 95% CI, 0.92–0.97), and, more modestly, of HCC (subHR, 0.95; 95% CI, 0.91–0.99) compared with those remaining inactive. The association was more pronounced in older adults, women, never smokers, non‐drinkers, and untreated participants (all p for interaction ≤ 0.03). Initiating MVPA among physically inactive adults with CHB was associated with lower risks of mortality and liver‐related outcomes. These findings provide large‐scale epidemiological evidence supporting further evaluation of PA promotion in physically inactive patients with CHB.