Likhona Masika (Presenter)
NIH
Bio: Dr Likhona Masika, MBChB, FCPath (South Africa). Currently working as a Post Doc Fellow in Clinical Chemistry at NIH
Authorship: L.S Masika1 ,B Stolze1, E. Elliott, J. Gu1, B.S Abel, M.C Skarulis , S. J Soldin1,2
1 Department of Laboratory Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, 2 Department of Medicine, Georgetown University
| Short Abstract Our findings showed a significant diurnal fluctuation for DHEA similar to that observed by Stolze et al. The morning values were higher than evening. The mean at 08h00 was 566ng/mL and at midnight 230ng/dL, the mean decrease was 60%, P= <0.001 and n=19. We demonstrated large DHEA diurnal concentration fluctuations requiring strict adherence to time of the blood draw and use of separate time dependent reference intervals. |
Long Abstract
Background: The study recently published by Stolze et al revealed significant diurnal fluctuations for 11-DOC, corticosterone, cortisone, androstenedione, and 17-OHP, all of which showed significantly higher values in the morning than in the evening (1). The literature has clearly documented diurnal variation in concentration measured for testosterone and cortisol.Data for DHEA variation have not been available. Method: We used an Agilent 6490 triple-quadrupole LC/MS-MS system equipped with an Agilent atmospheric pressure photo ionization (APPI) source. The liquid chromatography component was an Agilent 1100 isocratic pump and a 1200 Infinity liquid chromatography system including a micro vacuum degasser, binary pump and auto sampler. The column used was an Agilent Poroshell 120 SB-C8. 100 μL of sample was mixed with 150 μL of acetonitride containing deuterated internal standard and vortexed for 30 seconds, then centrifuged for 10 minutes at 13 000 RPM. 150 μL of the supernatant was transferred to 250 μL of HPLC grade water and vortexed for 10 seconds and 300 μL was injected into the system. Quantification by multiple reaction-monitoring (MRM) analysis was performed in the positive mode. The transitions selected were: mass-to-charge (m/z) 271.3 to 213.2. Nitrogen served as curtain and collision gas.
The study was performed in 19 normal adult volunteers. Morning samples were collected between 07h30 and 08h00, and paired midnight sample were taken between 23h30 and 24h00
Results: Our findings showed a significant diurnal fluctuation for DHEA similar to that observed by Stolze et al. The morning values were higher than evening. The mean at 08h00 was 566ng/mL and at midnight 230ng/dL, the mean decrease was 60%, P= <0.001 and n=19. Conclusion: We demonstrated large DHEA diurnal concentration fluctuations requiring strict adherence to time of the blood draw and use of separate time dependent reference intervals.
References & Acknowledgements:
1.Brian Stolze, Verena Gounden, Jianghong Gu, Brent S. Abel, Deborah P. Merke, Monica C. Skarulis and Steven J Soldin. Use of Micro-HPLC-MS/MS Method to Assess Diurnal Effects on Steroid Hormones. Clin Chem March 2015 vol 61 no 3 556-558
2.Barterl M, Van den Berg M, Sluyter F, Boomsma DI, de Geus EJ. Heritability of cortisol levels: review and simultaneous analysis of twin studies. Psychoneuroendocrinology 2003; 28: 121-37
3.Holst JP, Soldin SJ, Tractenberg RE, Guo T, Kundra P, Verbalis JG, et al. Use of steroid profile in determining the cause of adrenal insufficiency. Steroids 2007; 72:71-4
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