The Use of Routine Laboratory 17-Hydroxyprogesterone for Identification of Cases of 21-Hydroxylase Deficiency Congenital Adrenal Hyperplasia.

BACKGROUND: Clinical outcome studies of 21-hydroxylase deficiency congenital adrenal hyperplasia (21OHD CAH) may be subject to selection bias due to incomplete case ascertainment. This study aimed to develop a methodology for identifying existing CAH cases and explore its utility to study clinical outcomes. METHODS: 17-hydroxyprogesterone assays (17OHP) processed in NHS Greater Glasgow and Clyde between 2014 and 2022 were analysed based on 17OHP result (≥ 6 or < 6nmol/L), location, test frequency and clinical details. Identified cases were cross-referenced against local clinical data logs. For confirmed cases, current age, sex, age at diagnosis, mortality status, most recent blood pressure (BP) and anthropometry were collected. RESULTS: Assay results from 57,011 cases were extracted and, of these, 116 (F:M, 81:35) had confirmed CAH but 66 (57%) were not reported by any local clinical data logs. The median age at the time of the study was 33 years (range, 2, 75) and 95 (82%) were over 16 years (F:M, 69:26). In these adults, 52 (55%) were diagnosed in childhood (i.e. ≤ 16 years) and only 1 male was diagnosed in adulthood. The median body mass index (BMI) standard deviation score of children was 0.70 (-2.43, 3.15). Median BMI of adults was 28 (15, 56) and median adult and paediatric systolic BP was 120 mmHg (95, 153) and 106 mmHg (83, 130), respectively. CONCLUSION: The 17OHP-based algorithm that was used in this study represents a useful method for identifying existing cases of CAH and can allow improved understanding of routinely collected markers of clinical outcome.