6703 Age-Related Reference Intervals for 11-Oxygenated Androgens in Children

Abstract Disclosure: L. IJsselstijn: None. R. Zellerer: None. R. Oude Engberink: None. B. van Zelst: None. S.A. van den Berg: None. Context: 11-Oxygenated androgens have emerged as major components of several disorders of androgen excess. Levels of 11-keto androstenedione (11KA4), 11β-hydroxy androstenedione (11OHA4), 11-keto testosterone (11KT) and 11β-hydroxy testosterone (11OHT) have been mainly studied in adults and in relation to various disorders. Although it is known that 11-oxygenated androgens are pivotal in adrenarche and pubarche, well established reference intervals for children are lacking. Objective: To establish age-related reference intervals for 11-oxygenated androgens in children. Methods: Serum samples were collected from apparently healthy children with ages ranged 0-18 years (n=186, 108 boys and 78 girls). Concentrations of 11KA4, 11OHA4, 11KT and 11OHT were determined by isotope dilution mass spectrometry. Before measurement the serum was deproteinized and purified by solid-phase extraction. The lower limit of quantitation for 11KA4, 11KT and 11OHT were 3.0 ng/dL (0.10 nmol/L), and for 11OHA4 9.1 ng/dL (0.30 nmol/L). Results: For 11KA4 a difference between boys and girls was observed until the age of 6. In girls 11KA4 was undetectable where in boys concentration up to 9.61 ng/dL (0.32 nmol/L) were measured. From the age of 6 an increase of 11KA4 was observed with increasing age. From the age of 13 concentrations stabilized at 4.21-28.5 ng/dL (0.14-0.95 nmol/L) without a difference between boys and girls. 11OHA4 was detectable at all ages and showed no differences between boys and girls, except for an apparently slightly higher concentration for boys until the age of 4. The concentration 11OHA4 increased with age in an almost linear way. At the age of 18 concentrations were observed of 60.5- 296.4 ng/dL (2.00-9.80 nmol/L). For 11KT a similar relation between the concentration and age was observed until the age of 14. At the age of 14 a plateau seems to be reached at concentrations of 14.5-74.4 ng/dL (0.48-2.46 nmol/L), which slightly decreased from the age of 17. 11OHT was undetectable in both boys and girls up to the age of 9 years. After the age of 9 the concentration range increased by age up to 30.4 ng/dL (1.00 nmol/L). From the age of 12 11OHT was detectable in all girl samples, where as in boys samples with undetectable concentrations were present at all ages. Conclusions: Age-related reference ranges were established for 11KA4, 11OHA4, 11KT and 11OHT. Overall no differences were observed between boys and girls, except for 11KA4 at a young age. The concentrations measured at the age of 18 correspond to the adult values known from literature for all 4 11-oxygenated androgens. Presentation: 6/1/2024