BACKGROUND
“Short-term” samples are not the most appropriate for reflecting Chronic Cortisol Concentration (CCC). Although hair is used for reflecting the systemic cortisol level over “long-term”, its use appears clinically problematic. Local stress and non-stress related factors may release a circumscribed cortisol secretion that is accumulated in hair. Non-stressful earwax extraction methods may provide a more accurate specimen to measure CCC.
OBJECTIVE
Correlate cortisol levels using hair, serum and earwax samples
METHODS
Earwax from both ears of 37 controls were extracted using a clinical procedure commonly associated with local pain. One month later, earwax from the left ear side was extracted using the same procedure, and earwax from the right ear side was comfortably extracted, using an earwax self-sampling device. Participants also provided one centimetre of hair that represented the retrospective month of cortisol output, and one serum sample that reflected the effect of systemic stressors on cortisol levels. Earwax (ECC), Hair (HCC) and Serum (SCC) Cortisol Concentration were correlated and compared. Confounders´ effect on cortisol levels were studied.
RESULTS
Serum showed the largest and hair the lowest cortisol concentration (p<0.01). Left-ECC was larger than Right-ECC (p=0.03). Right-ECC was the only sample unaffected by confounders (all p>0.05). Right-ECC and HCC showed the only significant association (r=0.39; p=0.03).
CONCLUSIONS
The self-sampling device did not represent a local stressor for the ceruminous glands. It provided the cortisol level with the least likely to be affected by confounding factors over the previous month. ECC using the novel device may constitute another accurate, but more suitable and affordable specimen for measuring CCC.
Salivette, a relevant saliva sampling device for SARS-CoV-2 detection
