Hormone stability in human whole blood

Area of Science:

• Clinical Chemistry
• Endocrinology
• Laboratory Medicine

Background:

• Accurate hormone measurement is crucial for clinical diagnosis and monitoring.
• Pre-analytical variables, such as sample handling and storage, can significantly impact assay results.
• Understanding the stability of hormones in whole blood before plasma separation is essential for reliable testing.

Purpose of the Study:

• To investigate the impact of delayed plasma separation on the concentrations of 17 key hormones in human whole blood.
• To determine the effects of storage temperature (4°C vs. 24°C) and time (up to 24 hours) on hormone stability.

Main Methods:

• Human whole blood samples (EDTA) were stored at 4°C or 24°C for varying durations (0.5, 6, 24 hours).
• Plasma was separated, and concentrations of 17 hormones, including ACTH, AVP, insulin, and VIP, were measured.
• Statistical analysis, including nonlinear regression, was employed to identify significant changes and determine the time to a 10% concentration change.

Main Results:

• Significant concentration changes were observed for adrenocorticotropic hormone (ACTH), arginine vasopressin (AVP), insulin, and vasoactive intestinal peptide (VIP).
• ACTH decreased, while AVP and VIP increased, with time- and temperature-dependent patterns.
• Insulin levels decreased significantly after approximately 17 hours at both temperatures.

Conclusions:

• Delayed plasma separation from whole blood can compromise the accurate measurement of certain hormones.
• While many hormones remain stable, ACTH, AVP, insulin, and VIP are susceptible to changes during storage.
• Prompt processing of blood samples is recommended to ensure the integrity of hormone measurements.