Prevalence, incidence, and mortality of autoimmune diseases among adolescents and young adults in Mexico: an analysis based on the global burden of disease study 2021.

This nationwide analysis quantified the contemporary and future burden of six autoimmune diseases (ADs)-rheumatoid arthritis (RA), inflammatory bowel disease (IBD), multiple sclerosis (MS), type 1 diabetes mellitus (T1DM), asthma, and psoriasis-among Mexican adolescents and young adults (AYAs, 10-24 years) using the Global Burden of Disease 2021 database. Age-standardised prevalence (ASPR), incidence (ASIR), and mortality (ASMR) rates for 2021 were calculated by direct standardisation to the GBD world population; 1990-2021 temporal patterns were explored through Joinpoint regression to derive average annual percentage change, and Box-Jenkins ARIMA models projected trends up to 2035, incorporating diagnostic-capacity covariates. In 2021, RA had the greatest burden (ASPR 45.7/100,000; ASIR 9.1), with a striking female predominance and north-south variability. Although IBD remained infrequent, its mortality rose in states where colonoscopy access expanded, suggesting detection bias yet underscoring rising severity. MS prevalence and incidence climbed steadily, particularly among young women in urbanised regions. T1DM maintained the highest absolute caseload and incidence but showed slowly declining rates; nevertheless, ASMR inched upward, reflecting suboptimal metabolic control. Asthma, while still the most prevalent AD, exhibited a modest downward trajectory, whereas psoriasis incidence was stable, yet prevalence remained substantial, signalling chronic disease accumulation. Forecasts predict moderate growth in RA and MS cases, relative plateauing of IBD, asthma, and psoriasis, and continued contraction of T1DM incidence with a slight mortality uptick. Persistent geographic and sex-related inequities highlight the necessity for region-specific prevention strategies, earlier immune-modulating therapy, and equitable access to specialised care to mitigate the projected AD burden in Mexican AYAs.