Global trends and projections of early-onset CKD burden: a GBD 2021 analysis

Background: Chronic kidney disease (CKD) is a major global health concern. While adult CKD has been widely studied, systematic evaluation of early-onset CKD (ages 0-25) remains limited. Using Global Burden of Disease 2021 data, this study provides the first comprehensive assessment of early-onset CKD burden from 1990 to 2021 to inform prevention and control strategies. Methods: We analyzed age-standardized incidence, mortality, prevalence, and disability-adjusted life years (DALYs) among individuals aged 0-25 across Socio-demographic Index (SDI) quintiles. Temporal trends were quantified using segmented regression and average annual percentage change. Cross-country inequalities were measured via slope and concentration indices. Bayesian Age-Period-Cohort models projected burden through 2050. Das Gupta decomposition assessed contributions from population growth, aging, and epidemiologic shifts. Frontier analysis examined the relationship between SDI and DALYs to estimate preventable burden. Results: Early-onset CKD demonstrated divergent global patterns: mortality declined [estimated annual percentage change (EAPC) -0.87%] while incidence increased (EAPC 0.31%). Total cases rose to 41.79 million (EAPC 0.13%), whereas DALYs fell to 3.32 million (EAPC -0.89%). Mortality reductions were greatest in medium/low SDI regions, but incidence increases were also most pronounced there. SDI was inversely associated with mortality. Age patterns showed bimodal peaks: children under 5 (45.58% of new cases) and young adults 20-24 years (32.32% of DALYs), with higher male mortality in the latter group. Unknown etiologies dominated (58%-68%), followed by glomerulonephritis; in East Asia, type 1 diabetes accounted for 20.42% of deaths. Frontier analysis indicated limited prevention efficiency in low SDI settings and untapped potential in high SDI regions. Conclusions: Early-onset CKD showed declining mortality but rising incidence, likely reflecting improved survival, better ascertainment, and persistent risk exposures. Reducing this burden will require targeted action on SDI-related disparities, the high proportion of unknown etiology, and the shifting burden across childhood and young adulthood. In the context of the 2025 World Health Organization resolution integrating kidney health into the global noncommunicable disease agenda, these findings support stronger surveillance, early detection, and equitable resource allocation for younger populations.