Reference ranges for serum dehydroepiandrosterone sulfate and testosterone in adult men.J Androl. 2008 Nov-Dec; 29(6):610-7.JA
Dehydroepiandrosterone (DHEA) is the main adrenal androgen, which mostly exists in a sulfated version (DHEAS). Both DHEA and DHEAS are metabolic intermediates in the biosynthesis of the male sex hormone testosterone. In men, testosterone is involved in the regulation of fertility, libido, and muscle mass and is valuable for the assessment of gonadal, adrenal, and pituitary function and for the diagnosis of hypogonadism. The objective of the present study was to calculate age-specific reference ranges for serum DHEAS and serum testosterone using 1) linear regression and the mean +/- 1.96 standard deviation concept and 2) quantile regression. From the cross-sectional Study of Health in Pomerania a total of 1078 men aged 20-79 years were included in the analyses. Serum DHEAS and testosterone levels were quantified using IMMULITE 2500 immunoassays. Linear and quantile regression were performed to calculate age-specific reference ranges. Both statistical methods generated different results: The reference ranges based on linear regression identified 17 men (1.6%) with DHEAS levels and 45 men (4.2%) with serum testosterone levels outside the reference range. Using quantile regression, 54 men (5.0%) and 50 men (4.6%) with serum DHEAS and testosterone levels outside the range were detected, respectively. The present study established age-specific reference ranges for serum DHEAS and testosterone levels for men. Quantile regression should be preferred to calculate reference ranges; a better concordance with original data is possible because no distribution assumption is required and the robustness against outliers is given.