Endocrine Abstracts

Background: It is uncertain whether targeted monitoring of acute adrenal insufficiency (AI)–related adverse events, including sick day episodes (SDEs), adrenal crises (AC) and hospitalisations affects the occurrence of these events in children with 21-hydroxylase deficiency congenital adrenal hyperplasia (21-OHD CAH). This study aimed to evaluate temporal trends in AI-related adverse events in children with 21-OHD CAH using real-world data in the I-CAH registry.

Methods: Data on SDE, AC and hospitalisations were collected from 2022 to 2025 for children with 21-OHD CAH aged <18 years. These data were compared to results from 2016–2019 and 2019–2022.

Results: In 2025, 980 children (55 centres, 25 countries) with 5,053 visits and 1,723 patient-years were evaluated. Registry participation increased over time [222 patients (27 centres, 17 countries, 256 patient years data) in 2016–2019 and 513 patients (38 centres, 21 countries) with 880 patient years in 2019–2022]. There were no differences in the proportion of centres from low/middle-income vs high-income countries [33% (9/27) vs 67% (18/27), 29% (11/38) vs 71% (27/38) and 33% (18/55) vs 67% (37/55), P >0.1] in 2016, 2022 and 2025, respectively. The proportion of patients with salt-wasting (SW) CAH were lower over time [92% (204/222) in 2016, 79% (405/513 and 771/976) in 2022 and 2025, respectively], P<0.05. Daily glucocorticoid dosing regimens (hydrocortisone equivalent, mg/m²/day) differed, with a decrease in doses within the recommended range [59% (1288/2172) vs 56% (1734/3112] and an increase in values in the higher range [20% (439/2172) vs 23% (723/3112)] in 2019 and 2025, respectively, P =0.02. The median SDEs per patient-year per centre was 0.6 (10^th,90th: 0,8.3) in 2016–2019, 0 (0,1.7) in 2019–2022 and 0 (0,1.2) in 2022–2025 (P =0.04). Amongst 32 centres that participated in both 2022 and 2025 exercises, SDE rates decreased in 28% (9/32), increased in 31% (10/32) and remained unchanged in 40% (13/32).

Conclusion: I-CAH enables global benchmarking of acute AI-related adverse events in CAH and the number of centres that are participating in this exercise continues to increase. The fall in SDE rates that was previously observed in 2022 has been sustained over the following three years.