Increased physical activity achieving a ≥30% reduction in hepatic steatosis among individuals with MASLD in Saudi Arabia could reduce liver-related complications, deaths, DALYs, and healthcare costs by up to 14.2%, 12.3%, 24.2%, and 11.5% respectively over a 20-year horizon.
Key Findings
Results
MASLD prevalence in Saudi Arabia is projected to increase substantially from 2025 to 2045 under baseline conditions.
MASLD prevalence is projected to increase from approximately 10.0 million individuals in 2025 to 14.3 million in 2045.
This represents a projected increase of approximately 43% over the 20-year simulation period.
The current MASLD prevalence already affects over 30% of the Saudi population.
Projections were generated using a validated Markov model simulating MASLD progression from 2025 to 2045.
Results
Physical activity interventions achieving ≥30% relative reduction in hepatic steatosis are projected to reduce cumulative liver-related deaths by 4.3% to 12.3% depending on the proportion of patients achieving that reduction.
Three scenarios were evaluated: 10%, 20%, and 30% of individuals with MASLD achieving a clinically significant ≥30% relative reduction in hepatic steatosis.
Cumulative liver-related deaths declined by 4.3% in the 10% scenario, with proportionally greater reductions in the 20% and 30% scenarios up to 12.3%.
The model used disability-adjusted life years (DALYs) to measure health outcomes and U.S.-based direct healthcare costs to measure economic outcomes.
All three scenarios were described as 'aspirational' physical activity intervention scenarios.
Results
Physical activity interventions are projected to reduce hepatocellular carcinoma (HCC) cases by 4.9% to 14.2% across the three scenarios.
In the scenario where 10% of individuals with MASLD achieved ≥30% reduction in hepatic steatosis, HCC cases declined by 4.9%.
In the scenario where 30% of individuals achieved ≥30% reduction in hepatic steatosis, HCC cases declined by 14.2%.
Reductions in HCC cases were proportional to the percentage of the MASLD population achieving clinically significant hepatic steatosis reduction.
These projections were cumulative over the 2025–2045 simulation period.
Results
Decompensated cirrhosis cases are projected to decline by up to 14.0% under the most ambitious physical activity intervention scenario.
The reduction in decompensated cirrhosis cases ranged across the 10%, 20%, and 30% intervention scenarios, reaching up to 14.0% in the highest scenario.
Decompensated cirrhosis is a severe, life-threatening complication of advanced liver disease.
These reductions were modeled as resulting from upstream disease progression changes due to reduced hepatic steatosis.
The Markov model tracked disease stage transitions including steatosis, MASH, fibrosis, cirrhosis, decompensated cirrhosis, HCC, and death.
Results
Direct healthcare costs associated with MASLD are projected to decrease by 4.0% to 11.5% across the three physical activity intervention scenarios.
Economic outcomes were analyzed using U.S.-based direct healthcare costs applied to the Saudi MASLD population.
The 10% scenario yielded a 4.0% cost reduction; the 30% scenario yielded an 11.5% cost reduction.
Cost reductions are attributable to lower rates of advanced liver disease events including HCC, decompensated cirrhosis, and liver-related death.
The economic analysis covered the cumulative 20-year period from 2025 to 2045.
Results
DALYs associated with MASLD are projected to decline by 8.6% to 24.2% across the three intervention scenarios, representing the largest relative benefit measured.
DALYs declined by 8.6% in the 10% scenario and by 24.2% in the 30% scenario.
DALYs capture both years of life lost due to premature death and years lived with disability, making this a comprehensive measure of disease burden.
The DALY reductions were proportionally larger than cost reductions across all three scenarios, suggesting substantial quality-of-life gains.
These figures represent cumulative DALYs averted over the 2025–2045 projection period.
Methods
The study used a validated Markov model to simulate MASLD natural history and intervention impact over a 20-year horizon in Saudi Arabia.
The model simulated MASLD progression from 2025 to 2045.
The model was described as 'validated' and tracked transitions through MASLD disease stages.
The intervention mechanism modeled was a ≥30% relative reduction in hepatic steatosis, described as 'clinically significant,' achieved through increased physical activity.
Physical activity levels in Saudi Arabia have increased in recent years but MASLD prevalence continues to show an increasing trend.
Conclusions
The authors recommend integrating MASLD-specific outcomes into national physical activity promotion campaigns aligned with Saudi Vision 2030.
Saudi Vision 2030 is a national policy framework that includes health and physical activity promotion goals.
The findings were framed as supporting integration of MASLD outcomes into 'noncommunicable disease advocacy efforts.'
The authors concluded that 'increased physical activity could significantly reduce the future health and economic impacts of MASLD in Saudi Arabia.'
The study positioned its findings as evidence to support policy-level intervention rather than individual clinical guidance.
What This Means
This research suggests that getting more people with fatty liver disease (MASLD) in Saudi Arabia to exercise could have a substantial impact on the country's future health and economic burden. Using a computer simulation model, researchers projected that without intervention, the number of people with MASLD in Saudi Arabia would grow from about 10 million in 2025 to over 14 million by 2045. They then tested three scenarios in which 10%, 20%, or 30% of people with MASLD achieved a meaningful reduction in liver fat through increased physical activity, and measured the resulting changes in serious liver disease events, deaths, and costs over that 20-year period.
The results showed that even modest increases in the proportion of patients achieving liver fat reduction could produce meaningful benefits. In the most ambitious scenario—where 30% of MASLD patients achieved the target level of liver fat reduction—liver-related deaths could fall by more than 12%, liver cancer cases by more than 14%, and years of healthy life lost (DALYs) by nearly a quarter. Direct healthcare costs could also fall by more than 11%. These benefits scaled proportionally, meaning even getting 10% of patients to reach the goal produced measurable gains across all outcomes.
This research suggests that physical activity promotion, particularly when framed around measurable liver health outcomes, could be a cost-effective public health strategy in Saudi Arabia. The authors argue that national campaigns—such as those under Saudi Vision 2030—should explicitly incorporate MASLD-related health outcomes as goals, not just general fitness metrics, to motivate and measure progress. While the model relies on assumptions and U.S.-based cost data applied to Saudi Arabia, the findings highlight that treating physical inactivity as a modifiable risk factor for serious liver disease could have large-scale benefits for population health.
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Wallace C, Alessy S, Abaalkhail F, Alghamdi S, Alfadda A, Al Qabbani A, et al.. (2026). Modelling the impact of physical activity on MASLD in Saudi Arabia.. PloS one. https://doi.org/10.1371/journal.pone.0354332