Cortisol Awakening Response (CAR)
Performed by: NutriPATH
The Cortisol Awakening Response (CAR) test is a non-invasive saliva test that serves as a reliable marker of stress response and a critical tool for revealing adrenal imbalances. Lifestyle, physical and psychological stresses put constant demands on the adrenal glands. If they become depleted adrenal fatigue or insufficiency may be experienced.
The Cortisol Awakening Response (CAR) test is a unique assessment measuring the predictable rise and fall in cortisol within the first hour of awakening. The test is essential in evaluating the overall function of the HPA axis. In this particular test we measure cortisol immediately on rising, 30 minutes post waking, 60 minutes post waking, 12:00 (noon), 4:00pm and 8:00pm.
The CAR test allows your physician to determine how healthy your HPA axis is which useful in assessing the HPA-axis.
The CAR test is an appropriate tool in practice for most of your patients as it provides an easy assessment of their ability to deal with stressors and is also reflective of how well they have dealt with stressors in the past.
Analytes:
- Cortisol (on waking)
- Cortisol +30 mins
- Cortisol +60mins
- Cortisol 12:00noon
- Cortisol 4:00pm
- Cortisol 8:00pm
- DHEAs
CORTISOL AWAKENING RESPONSE:
The cortisol awakening response (CAR) test is a transient, immediate rise in cortisol upon awakening and is distinct from the diurnal rhythm. In a normal individual without significant stressors, cortisol is highest in the morning shortly after awakening, rises by up to 60% roughly 30 minutes after awakening, then steadily drops throughout the day, reaching the lowest level during sleep in the very early morning about 2 am. A loss of the expected curve with its characteristic morning peak and steady decline towards evening may suggest HPA axis dysfunction.
CAR RISE RESPONSE WITHIN NORMAL RANGE:
The rise in Cortisol from waking to 30 minutes post-waking is within normal range. This indicates normal Cortisol production/metabolism.
CAR DECLINE RESPONSE WITHIN NORMAL RANGE:
The decline in Cortisol from waking to 60 minutes post-waking is within normal range.
This is consistent with normal Cortisol production/metabolism.
LOW/LOW NORMAL MIDDAY CORTISOL LEVEL:
Midday Cortisol level is below mean range and suggestive of adrenal insufficiency. This suggests suboptimal adrenal functioning, and if accompanied by low evening cortisol and low DHEA, suspect adrenal fatigue. Suggest supplementation with DHEA and standard adrenal support.
LOW/LOW NORMAL LATE AFTERNOON:
Late afternoon cortisol level insufficiency. This suggests by low evening cortisol and low DHEA, suspect adrenal fatigue. Suggest supplementation with DHEA and standard adrenal support.
EVENING CORTISOL LEVEL WITHIN RANGE:
Saliva evening cortisol level is normal and within range.
References:
Tsigos C, Chrousos GP. Hypothalamic-pituitary-adrenal axis, neuroendocrine factors and stress. J Psychosom Res. 2002 Oct;53(4):865-71. doi: 10.1016/s0022-3999(02)00429-4. PMID: 12377295. [L]
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. [L]
Clow A, Hucklebridge F, Stalder T, Evans P, Thorn L. The cortisol awakening response: more than a measure of HPA axis function. Neurosci Biobehav Rev. 2010 Sep;35(1):97-103. doi: 10.1016/j.neubiorev.2009.12.011. Epub 2009 Dec 22. PMID: 20026350. [L]
Hackett RA, Kivimäki M, Kumari M, Steptoe A. Diurnal Cortisol Patterns, Future Diabetes, and Impaired Glucose Metabolism in the Whitehall II Cohort Study. J Clin Endocrinol Metab. 2016 Feb;101(2):619-25. doi: 10.1210/jc.2015-2853. Epub 2015 Dec 8. PMID: 26647151; PMCID: PMC4880118. [L]
Hammer F, Deutschbein T, Marx A, Güder G, Michalski R, Ertl G, Allolio B, Angermann CE, Störk S, Fassnacht M. High evening salivary cortisol is an independent predictor of increased mortality risk in patients with systolic heart failure. Int J Cardiol. 2016 Jan 15;203:69-73. doi: 10.1016/j.ijcard.2015.10.084. Epub 2015 Oct 20. PMID: 26492313. [L]
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Biomarkers included in this panel:
CAR Decline Response
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Learn moreCortisol Profile, Evening
The marker "Cortisol Profile, Evening" refers to the measurement of cortisol levels in the body during the evening hours, typically reflecting the end-of-day physiological status of an individual's hypothalamic-pituitary-adrenal (HPA) a
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The cortisol profile, particularly measurements taken at midday, provides significant insights into the diurnal pattern of cortisol secretion, which is critical for assessing adrenal gland function and the body's response to stress. Cortisol, a g
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Learn moreCortisol Profile, Waking
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Learn moreCortisol/DHEAS Ratio CAR
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Learn moreDHEAS Profile, Waking+30min
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