Session: THR 270-288-Steroid Hormone Actions and Biosynthesis
Poster Board THR-270
Methods: Serum samples were collected from 12 male and 12 female subjects. Samples were collected early in the morning and in the evening of the same day for each subject to assess diurnal variation. Subsequent samples were collected early morning on 6 different days to assess intra-individual variation. Inter-individual variation was assessed using all the data form the samples collected in the mornings.
Analysis of testosterone, androstenedione, DHT and DHEA was performed using LC-MS/MS with on-line solid phase extraction.
Results: The analytical CV of the assay in the female range was 4, 7, 7 and 10%. In males it was 3, 4, 9 and 9% for testosterone, androstenedione, DHT and DHEA respectively. All androgens gave higher results in the morning compared to the evening. This difference was statistically different for all androgens for both sexes (paired sample t test <0.005).
The mean inter-individual CVs were similar in males and females for testosterone, androstenedione and DHEA. DHT showed a higher inter-individual (55% vs 37%) and intra-individual (24% vs 12%) CV in females compared to males.
The reference change values for females were 28, 34, 42 and 72% for testosterone, androstenedione, DHT and DHEA respectively. In males the reference change values were 22, 41, 25 and 48% for testosterone, androstenedione, DHT and DHEA respectively.
Conclusions: Determination of the biological variation for androgens in males and females separately enables the clinician to better interpret results obtained. The calculation of the reference change value incorporates the analytical CV to aid in the determination of significant changes within individuals.
Acknowlegements: The NATSAL team
Disclosure: FCWW: Consultant, Besins Healthcare, Consultant, Repros Inc, Research Funding, Besins Healthcare, Research Funding, Bayer Schering Pharma. Nothing to Disclose: LO, JA, WM, BGK
*Please take note of The Endocrine Society's News Embargo Policy at https://www.endocrine.org/news-room/endo-annual-meeting
See more of: Abstracts - Orals, Poster Previews, and Posters