Modelling the impact of physical activity on MASLD in Saudi Arabia

Background and aims: Insufficient physical activity contributes to the global rise of metabolic dysfunction–associated steatotic liver disease (MASLD). Although physical activity levels in Saudi Arabia have increased in recent years, MASLD shows an increasing prevalence trend, affecting over 30% of the population. This study aimed to determine the impact of increased physical activity, and resulting reduction in hepatic steatosis, on the projected health and economic burden of MASLD in Saudi Arabia. Methods: We simulated MASLD progression from 2025 to 2045 using a validated Markov model. Three aspirational physical activity intervention scenarios were evaluated, assuming that 10%, 20%, and 30% of individuals with MASLD achieved a clinically significant ≥30% relative reduction in hepatic steatosis. Health outcomes were measured in disability-adjusted life years (DALYs), and economic outcomes were analyzed using U.S.-based direct healthcare costs. Results: MASLD prevalence in Saudi Arabia is projected to increase from approximately 10.0 million in 2025 to 14.3 million in 2045. In scenarios where 10%, 20%, and 30% of individuals with MASLD achieved a ≥ 30% reduction in hepatic steatosis, cumulative liver-related deaths are projected to decline by 4.3%–12.3%, hepatocellular carcinoma cases by 4.9%–14.2%, and decompensated cirrhosis cases by up to 14.0%. Direct health care costs are estimated to reduce by 4.0%–11.5%, and DALYs are projected to decline by 8.6%–24.2% across scenarios. Conclusions: Increased physical activity could significantly reduce the future health and economic impacts of MASLD in Saudi Arabia. Achieving a ≥ 30% reduction in hepatic steatosis among individuals with MASLD could reduce liver-related complications, deaths, DALYs, and healthcare costs. These findings support the integration of MASLD-specific outcomes into national physical activity promotion campaigns and noncommunicable disease advocacy efforts, aligned with Saudi Vision 2030.