Serum and hair steroid profiles and their associations with body composition in adolescence.

Objective
Accurate assessment of steroid hormones is essential for understanding sexual development and metabolic health. Blood-based steroid assays are informative but invasive and reflect only short-term fluctuations. We compared serum and hair steroid hormone profiles in adolescents and examined their associations with body size and composition, with attention to sex-specific patterns.Design
Cross-sectional analyses in a population-based sample of adolescents attending the 8-year follow-up examinations of the PANIC study in the city of Kuopio, Finland.Methods
The analyses included 241 late- or post-pubertal adolescents aged 15 to 16 years (104 girls, 137 boys). The participants underwent detailed clinical assessments, including anthropometry and dual-energy X-ray absorptiometry. Paired serum and scalp hair samples were collected and analyzed using liquid chromatography-mass spectrometry to quantify progestagens, androgens, 11-oxy androgens, mineralocorticoids, and glucocorticoids.Results
A broad spectrum of steroids was reliably detected in both serum and hair. Hair samples revealed distinct profiles characterized by pronounced accumulation of pregnenolone and measurable levels of cortisone, cortisol, dehydroepiandrosterone, androstenedione, androstanedione, 11β-hydroxyandrostenedione, 11-ketoandrostenedione, testosterone, and dihydrotestosterone, indicating active peripheral metabolism. Importantly, androgen levels in both serum and hair correlated more strongly with body size and composition in boys than in girls, suggesting sex-specific regulation of metabolic processes.Conclusions
Hair steroid profiling represents a feasible, non-invasive alternative to serum analysis, capturing both systemic hormone levels and localized metabolic activity. This approach shows considerable promise for clinical endocrinology; however, further validation across developmental stages and diverse disease contexts is necessary before it can be adopted into clinical practice.