Global disability trends in BMI-attributed knee osteoarthritis: Historical analysis and ARIMA-based projections...

Knee osteoarthritis (KOA) is a major cause of disability, particularly among individuals aged 50 and older. High body mass index (BMI) is a key risk factor for both the onset and progression of KOA. As obesity rates rise globally and populations age, understanding the long-term trends and projections of KOA burden attributable to high BMI is critical for informing public health interventions. Data from the Global Burden of Disease 2021 database were used to assess the years lived with disability (YLDs) attributable to high BMI in KOA. The study focused on 6 highly populated countries across 6 continents: the United States and Australia (high socio-demographic index [SDI] countries), and Russia, China, Brazil, and Nigeria (middle- and low-SDI countries). Temporal trends were analyzed using the autoregressive integrated moving average model, with projections for 2030, 2040, and 2050. An interactive visualization tool was also developed to explore global and regional variations in KOA burden. Autoregressive integrated moving average projections indicate that the global population aged 50 and older will reach 2.96 billion by 2050 (95% uncertainty interval: 2.44-3.49 billion). From 1990 to 2021, global YLDs due to high BMI in KOA increased by approximately 209%, rising from 1.1 million to 3.4 million. Projections suggest this number will rise to 6.6 million by 2050. Women were disproportionately affected, with a higher growth rate in YLDs compared to men. The increasing aging population is expected to further exacerbate the burden of KOA attributable to high BMI. The burden of KOA attributable to high BMI has risen steadily since 1990 and is projected to nearly double by 2050, reaching about 6.6 million YLDs. Women, older adults, and populations in middle- and low-SDI countries will face the greatest increases. These findings emphasize the urgent need for targeted obesity prevention and management, particularly in aging and resource-limited settings. Coordinated public health policies and multidisciplinary interventions are essential to reduce the future health and economic impacts of KOA.