Add-On: CAR

This test measures the cortisol awakening response (CAR). It can be added to any of the following tests: Adrenocortex Stress Profile, Menopause Plus™, Rhythm Plus™, Male Hormones Plus™, and One Day Hormone Check™.

The cortisol awakening response (CAR) can be a valuable addition to other hormone panels.

What Exactly is Tested in the Cortisol Awakening Response Add-On by Genova Diagnostics?

Three salivary measurements are taken to  assess the cortisol awakening response, which is the natural increase in cortisol levels that occurs within the first hour after waking. By evaluating cortisol levels at these time points, the CAR profile provides insights into the body's stress response dynamics and diurnal cortisol rhythm.

The test assesses the CAR through the following salivary measurements:

Cortisol levels immediately upon waking (0 minutes post-waking)

Cortisol levels approximately 30 minutes after waking

Cortisol levels between 7 and 9 am, or about 60 minutes after waking

Why is the Cortisol Awakening Response Clinically Relevant?

In healthy individuals, cortisol is expected to rise in the morning by as much as 50%, peak approximately 30 minutes after waking, and fall back to morning waking levels within 60 minutes of waking.  [5.]  This is called the Cortisol Awakening Response, or CAR, and it provides valuable insight into the functioning of the HPA axis.  [7.]

The CAR is clinically relevant because it reflects HPA axis function, which is associated with various physiological and psychological factors.  Research suggests that a robust CAR is indicative of healthy stress regulation and adaptation, while blunted or exaggerated CARs are linked to conditions such as chronic stress, PTSD, depression, chronic fatigue, and burnout.  [4., 5., 8., 10., 11.]  

Assessing CAR through laboratory testing such as the Cortisol Awakening Response Add-On by Genova Diagnostics can aid in identifying dysregulations in the hypothalamic-pituitary-adrenal (HPA) axis, which plays a central role in the body's stress response system. [1.]

The addition of the CAR test to other hormone panels provides additional insight into the effects of chronic stress on an individual’s unique hormone balance.  Chronic stress alters HPA axis function, which can also alter HPG (hypothalamic-pituitary-gonadal) function and cause a range of downstream effects.  [9.]

Who Can Benefit from the Cortisol Awakening Response Add-On test by Genova Diagnostics? 

The Cortisol Awakening Response (CAR) Add-On by Genova Diagnostics may shed light on stress-related factors in people already struggling with a variety of hormonal issues. [11.]  This may include complex concerns including: 

Infertility in men or women

Men or women with hormone issues and chronic fatigue syndrome, chronic pain, fibromyalgia, certain autoimmune diseases, depression, or PTSD [1., 3., 4., 11.]

Men or women who have not responded as expected to prior therapies for hormone imbalance 

Men or women with complex presentations, especially in the setting of subjective or objective high stress levels

Presentations that include sleep problems [4.]

Men with chronically low testosterone or a testosterone/estrogen imbalance

Women with irregular cycles

PCOS

Women with variable luteal phase shifts from month-to-month

Women whose hormonal symptoms tend to fluctuate throughout her cycle

Women struggling with PMS, mid-cycle spotting, migraines, etc.

Women struggling with difficult symptoms in perimenopause or menopause

Collection and Shipping

This is an add-on test.  For full collection and shipping instructions, click here.  

References

[1.] Adam EK, Quinn ME, Tavernier R, McQuillan MT, Dahlke KA, Gilbert KE. Diurnal cortisol slopes and mental and physical health outcomes: A systematic review and meta-analysis. Psychoneuroendocrinology. 2017 Sep;83:25-41. doi: 10.1016/j.psyneuen.2017.05.018. Epub 2017 May 24. PMID: 28578301; PMCID: PMC5568897.

[2.] Ahn RS, Lee YJ, Choi JY, Kwon HB, Chun SI. Salivary cortisol and DHEA levels in the Korean population: age-related differences, diurnal rhythm, and correlations with serum levels. Yonsei Med J. 2007 Jun 30;48(3):379-88. doi: 10.3349/ymj.2007.48.3.379. PMID: 17594144; PMCID: PMC2628086.

[3.] Clow A, Thorn L, Evans P, Hucklebridge F. The awakening cortisol response: methodological issues and significance. Stress. 2004 Mar;7(1):29-37. doi: 10.1080/10253890410001667205. PMID: 15204030.

[4.] Fries E, Dettenborn L, Kirschbaum C. The cortisol awakening response (CAR): facts and future directions. Int J Psychophysiol. 2009 Apr;72(1):67-73. doi: 10.1016/j.ijpsycho.2008.03.014. Epub 2008 Sep 30. PMID: 18854200.

[5.] Lim WT, Torpy DJ. Chronic Fatigue Syndrome. [Updated 2023 Aug 30]. In: Feingold KR, Anawalt B, Blackman MR, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279099/

[6.] Nomura S, Fujitaka M, Jinno K, Sakura N, Ueda K. Clinical significance of cortisone and cortisone/cortisol ratio in evaluating children with adrenal diseases. Clin Chim Acta. 1996 Dec 9;256(1):1-11. doi: 10.1016/s0009-8981(96)06392-9. PMID: 8960783.

[7.] Stalder T, Kirschbaum C, Kudielka BM, Adam EK, Pruessner JC, Wüst S, Dockray S, Smyth N, Evans P, Hellhammer DH, Miller R, Wetherell MA, Lupien SJ, Clow A. Assessment of the cortisol awakening response: Expert consensus guidelines. Psychoneuroendocrinology. 2016 Jan;63:414-32. doi: 10.1016/j.psyneuen.2015.10.010. Epub 2015 Oct 20. PMID: 26563991.

[8.] Stanczykiewicz Bartłomiej Stańczykiewicz, Bogudzinska Bogna Bogudzińska, Kowalski KE, Misiak B. The association between depression and the cortisol awakening response is moderated by loneliness in men from a non-clinical sample. Psychoneuroendocrinology. 2024;160:106924-106924. doi:https://doi.org/10.1016/j.psyneuen.2023.106924

[9.] Toufexis D, Rivarola MA, Lara H, Viau V. Stress and the reproductive axis. J Neuroendocrinol. 2014 Sep;26(9):573-86. doi: 10.1111/jne.12179. PMID: 25040027; PMCID: PMC4166402.

[10.] Wessa M, Rohleder, Kirschbaum C, Flor H.  Altered cortisol awakening response in posttraumatic stress disorder. Psychoneuroendocrinology. 2006;31(2):209-215. doi:https://doi.org/10.1016/j.psyneuen.2005.06.010

[11.] Wüst S, Wolf J, Hellhammer DH, Federenko I, Schommer N, Kirschbaum C. The cortisol awakening response - normal values and confounds. Noise Health. 2000;2(7):79-88. PMID: 12689474.