Global regional and national burden and trends of early-onset Parkinson’s disease from 1990 to 2021

Parkinson's disease (PD) is often perceived as an elderly condition, overshadowing its impact on younger populations. This study assesses the global, regional, and national burden of early-onset PD (EOPD) in individuals aged 20-49 years from 1990 to 2021 using data from the Global Burden of Disease Study 2021. The estimated annual percentage change (EAPC) quantified temporal trends, while the Socio-Demographic Index (SDI) evaluated socioeconomic development. Decomposition analysis identified factors driving burden changes, while health inequality analysis quantified cross-national disparities. Findings reveal that global incident cases, prevalent cases, and years lived with disability (YLDs) for EOPD more than doubled over three decades. Age-standardized rates per 100,000 increased for incidence (1.46-2.35), prevalence (10.03-14.00), and YLDs (1.65-2.27), with corresponding EAPCs of 1.42%, 1.09%, and 1.05%, respectively. Men had approximately 1.5 times higher burden than women. Health inequalities have worsened, with middle and high-middle SDI regions, especially East Asia and Andean Latin America, exhibiting the fastest growth rates. EOPD burden positively correlated with pesticide use. Rising YLDs were primarily driven by increased prevalence in higher SDI regions and population growth in lower SDI regions. These trends highlight the need for targeted strategies to reduce risk and promote early diagnosis in younger populations globally.