Global Insights into Interstitial Lung Diseases and Pulmonary Sarcoidosis:Demographic and Developmental Disparities, Projections, andBiomolecular Implications

INTRODUCTION: Interstitial Lung Diseases (ILDs) and lung sarcoidosis represent major global health challenges. Despite their increasing clinical incidence, comprehensive data on their global burden remain limited. METHODS: Using data from the Global Burden of Disease (GBD) 2021 study, we analyzed the incidence, prevalence, mortality, and Disability-Adjusted Life Years (DALYs) of ILDs across 21 regions, 204 countries from 1990 to 2021. Disparities in burden were assessed in relation to sex, age, and Socio-Demographic Index (SDI), and Bayesian projections were performed to 2035. RESULTS: From 1990 to 2021, global age-standardized rates (per 100,000) increased: Age- Standardized Incidence Rate (ASIR) from 3.77 (95% UI: 3.27-4.28) to 4.55 (4.06-5.04); Age- Standardized Prevalence Rate (ASPR) from 45.99 (39.42-53.78) to 50.01 (44.24-56.77); Age- Standardized Mortality Rate (ASMR) from 1.52 (1.25-1.87) to 2.28 (1.96-2.56); and DALYs from 37.15 (30.62-45.37) to 47.62 (41.26-53.17). Geographic heterogeneity was evident, with the highest burden in high-SDI regions. Males consistently exhibited higher rates than females, particularly in high-SDI areas. Burden increased with age, peaking at 85-89 years for ASPR. Projections to 2035 revealed a decline in age-standardized rates, but the decline in ASDR was expected to be more moderate. DISCUSSION: The epidemiology of ILDs and lung sarcoidosis showed marked disparities by geography, age, and SDI. The rising absolute burden warrants equitable healthcare resource allocation and integration of emerging clinical technologies. CONCLUSIONS: The epidemiology of ILDs and sarcoidosis exhibited marked disparities across geography, age, sex, and SDI. Although standardized rates are projected to decline, absolute disease burdens will continue to rise due to aging populations. Addressing this challenge requires equitable distribution of healthcare resources, biomarker-guided surveillance, innovative targeted therapies, and emerging technologies.