The Disease Burden of ILD at the Global, Regional, and National Levels from 1990 to 2021, and Projections Until 2035: Findings from the 2021 Global Burden of Disease Study with Focus on China.

OBJECTIVES: Interstitial lung disease (ILD) and pulmonary sarcoidosis are chronic respiratory conditions characterized by progressive inflammation and fibrosis, contributing to significant global health challenges. Understanding their epidemiological trends is critical for public health strategy development, particularly in China. STUDY DESIGN: Systematic analysis of the GBD 2021 dataset. METHODS: This study employed data from the Global Burden of Disease Study 2021 to assess incidence, prevalence, mortality, and disability-adjusted life years (DALYs) for ILD and pulmonary sarcoidosis across 204 countries and territories from 1990 to 2021, with detailed analysis of China. Methods included age-standardization, heatmap visualization, frontier analysis, and ARIMA modeling to project trends through 2035. RESULTS: Globally, from 1990 to 2021, the age-standardized incidence rate of ILD and pulmonary sarcoidosis increased by 21%, while the age-standardized mortality rate rose by 50%. In China, the age-standardized incidence rate increased by 20.8% (23.4% in males vs. 16.9% in females), and the age-standardized prevalence rate increased by 7.1%. In contrast to the global trend, China experienced a 4.9% decline in age-standardized mortality and a 13.9% decline in age-standardized DALY rate over the same period. The disease burden was highest among males aged 65-74 years, and all burden indicators were consistently higher in males than in females. Geographically, high-SDI regions had the highest age-standardized incidence rates, whereas China remained at an intermediate level. Projections through 2035 suggest that China's age-standardized incidence rate will remain stable, while the age-standardized mortality rate will continue to decline. CONCLUSIONS: The disease burden of ILD and pulmonary sarcoidosis shows substantial variation by region, age, and gender, with China demonstrating progress in mortality reduction despite rising incidence. Future efforts should prioritize targeted interventions for high-risk groups and enhance early diagnosis to mitigate the growing burden.