SAT-458 - Predicting Treatment Quality in Children and Adolescents with Congenital Adrenal Hyperplasia using Insulin and Renin

Background: Monitoring treatment quality in congenital adrenal hyperplasia (CAH) remains challenging. Current assessment relies on bone age and serum steroid measurements, which are imprecise and require considerable expertise. Reliable biochemical indicators are lacking. Most research has focused on mass spectrometry–based steroid metabolite profiling, which demands specialized equipment and expert interpretation. Whether treatment adequacy can be predicted by other, routinely available non steroid laboratory parameters has not been systematically explored, despite their established relevance for long term cardiometabolic risk.

Aim: To develop and evaluate a predictive score for undertreatment in children and adolescents with CAH using clinical and non steroid laboratory parameters.

Methods: We prospectively recruited patients with genetically confirmed 21 hydroxylase deficiency (CYP21A2 mutations) from four European pediatric endocrinology centers. Clinical features and standard laboratory analyses—including steroid and lipid profiles, glucose, insulin, and renin—were assessed at three outpatient visits. Treatment status was classified as optimal, undertreatment, or overtreatment by expert endocrinologists. Logistic regression analyses were performed to identify predictors of undertreatment and construct a predictive model.

Results: A total of 233 visits from 81 patients (37 female, 43 prepubertal) were analyzed. Undertreated patients showed significantly lower HDL-cholesterol (p = 0.007), higher insulin (p = 0.005), higher renin (p = 0.003), and increased height SDS (p = 0.014) compared to optimally treated patients. The final predictive model, based on 60 visits, retained insulin (coefficient 1.15) and renin (1.038) as independent predictors. At a threshold of ≥30–36, sensitivity was 71%, specificity 84%, and overall correct classification 80%. The ROC curve yielded an AUC of 0.785.

Conclusion: Serum insulin and renin, two inexpensive and routinely measured parameters, predict undertreatment in children and adolescents with CAH with high accuracy. Their dual relevance for short term treatment monitoring and long term cardiometabolic risk underscores their potential as practical, accessible tools to complement current strategies.

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