Trends, inequalities and time-series based prediction of knee osteoarthritis attributed to high body-mass-index: findings from global burden of disease 2021.

Background: High body-mass-index (BMI) has been shown to be a risk factor for knee osteoarthritis (KOA). Previous studies have examined the global or regional burden of osteoarthritis in multiple joints, including the hip, knee, and hand. However, there is no comprehensive analysis and prediction of the global burden of KOA attributed to high BMI. Methods: Disease burden of KOA attributable to high BMI, from 1990 to 2021, were extracted from the Global Burden of Disease (GBD) 2021. Trends were analyzed at the global, regional, and national levels, with subgroup analyses. Joinpoint regression, age-period-cohort model, decomposition analysis, cross-country inequalities were used to analyze the trend of disease burden from multiple dimensions. Autoregressive integrated moving average (ARIMA) model, a time-series based forecasting algorithms, was applied to predict the burden for the next 20 years. Results: From 1990 to 2021, the risk factor attribution of high BMI in KOA increased from 25.44 % (95 % CI: -2.38 %-48.66 %) to 33.52 % (95 % CI: -3.38 %-61.92 %). Globally, regionally, and nationally, the burden of KOA attributed to high BMI showed a sharp increase. Except for the decline observed in high sociodemographic index (SDI) regions from 2000 to 2005, the burden exhibited an upward trend across all other time periods and regions. Age, cohort, and period had significant impacts on disease burden. Both population growth and epidemiological changes contributed positively to the increase in the burden. Economic and social development led to increasing disparities, with lower-SDI countries showing better health outcomes. ARIMA model showed that a continued rise in the burden of KOA due to high BMI globally through 2041. Conclusions: KOA attributable to high BMI has imposed a substantial burden globally, regionally, and nationally over the past 30 years, with a marked increase. The projections indicate a further increase in the global burden over the next 20 years. Measures need to be taken for targeted preventive intervention. The translational potential of this article: High BMI is an important risk factor for KOA. The disease burden of KOA attributable to high BMI has increased significantly over the past 30 years. This burden is concentrated in economically developed areas, although the growth rate in less developed regions surpasses that of developed regions. This study suggested that targeted interventions addressing disease patterns across socioeconomic contexts are crucial to mitigating the burden of KOA attributable to high BMI. In addition, it is necessary to pay more attention to the disease burden of female.