The cortisol awakening response (CAR) by Precision Analytical offers a comprehensive assessment of cortisol levels at specific time points after waking, providing valuable insights into the body's stress response dynamics.
Cortisol, often termed the "stress hormone," plays a crucial role in regulating various physiological processes, including metabolism, immune function, and the body's response to stressors. The CAR profile measures cortisol levels upon waking and at subsequent time points, allowing for the evaluation of the natural diurnal rhythm of cortisol secretion and the magnitude of the cortisol response to the morning awakening.
This information can aid in assessing individual stress resilience, identifying abnormalities in cortisol secretion patterns, and guiding personalized interventions to optimize stress management and overall well-being.
This test cannot be ordered for patients under 12 years of age.
Five salivary measurements are taken during a 24 hour period in the Cortisol Awakening Response Profile. These measurements allow for the assessment of 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.
Additionally, an individual’s salivary cortisone measurements are reported for each of the 5 time points. Knowing the cortisone levels in saliva is necessary for a complete understanding of adrenal function; for example, if the diurnal cortisol curve is low but the cortisone curve is elevated, this demonstrates increased activity of the enzyme 11b-HSD2 that deactivates cortisol to cortisone. When only the diurnal cortisol curve is available, the total amount of adrenal cortisol produced is not known. [6.]
The test assesses the following measurements throughout a 24 hour period:
Cortisol/cortisone levels immediately upon waking (0 minutes post-waking)
Cortisol/cortisone levels approximately 30 minutes after waking
Cortisol/cortisone levels approximately 60 minutes after waking
Cortisol/cortisone levels in the afternoon
Cortisol/cortisone levels at bedtime
It also provides a total cortisol level and a total cortisone level over the 24 hour collection period.
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 Cortisol Awakening Response (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., 9., 10.] Assessing CAR through laboratory testing such as the Cortisol Awakening Response by Precision Analytical 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 Cortisol Awakening Response (CAR) by Precision Analytical may shed light on underlying health and disease factors in many groups of people, providing information that can direct the course of stress-related treatment:
Individuals with Stress-related Disorders: Research suggests that dysregulation of the CAR is associated with various stress-related disorders such as anxiety, depression, and post-traumatic stress disorder (PTSD). [3., 10.]
Individuals with Underlying Chronic Inflammation or Immune Dysfunction: the CAR may help clinicians understand the link between a patient’s mental or emotional stress and immune dysfunction (the mind-body connection). [3.]
People with Mood Disorders: Blunted or exaggerated CARs have been linked to mood disorders, including major depressive disorder and bipolar disorder, making CAR assessment valuable in diagnosing and managing these conditions. [1.]
Patients with Sleep Disturbances: Disturbances in the CAR have been observed in individuals with sleep disorders such as insomnia and obstructive sleep apnea, indicating the potential utility of CAR testing in evaluating sleep-related issues. [4.]
Individuals Experiencing Fatigue or Burnout: The CAR has been implicated in fatigue and burnout, with blunted CARs often seen in individuals experiencing chronic fatigue syndrome or burnout syndrome. [1., 4.]
People with Chronic Pain: Chronic pain conditions have been associated with alterations in the CAR, highlighting the relevance of CAR assessment in individuals with chronic pain conditions. [4.]
Individuals Undergoing Stress Management Interventions: CAR profiling can aid in monitoring the effectiveness of stress management interventions, allowing clinicians to adapt and emphasize treatment strategies based on an individual’s needs. [10.]
By assessing CAR, clinicians can gain insights into HPA axis function and stress response dynamics, facilitating personalized treatment approaches and improved patient outcomes.
⏰ Your healthcare practitioner will tell you when during the day to collect this sample.
💤 Collect your sample on a day in which you did not have significant sleep disturbances.
❌ You must avoid certain beverages and activities before and during the collection period.
💊 If you are taking hormones, consult the information below and your healthcare provider to discuss collection timing.
🧊 Freeze all samples within 12 hours of collection. Keep your saliva samples frozen until you ship them.
📦 Samples should be shipped to the lab as soon as possible after sample collection.
📄 You MUST send the completed test requisition form back to the lab with your samples. If you are in MD, NY, or RI, you must also send a lab order document from your healthcare provider. Failure to send these forms with your samples may result in a recollection.
Collect your sample on a day in which you did not have significant sleep disturbances.
If you are taking:
Oral Hydrocortisone: Please review the video instructions HERE.
Glucocorticoids, check with your healthcare provider regarding when you should collect your samples.
Day before sample collection
DO NOT use hydrocortisone cream.
This applies to both the patient and anyone else in the household.
DO NOT exercise.
DO NOT drink caffeine or alcohol the night before sample collection.
Day of sample collection
DO NOT floss your teeth until all samples have been collected.
WAIT to brush your teeth until
Morning: After collection 3
Evening: After collection 5
WAIT to eat until:
Morning: After collection 3
Evening: After collection 4
Saliva Collection
Set the following items next to your bed the night before your collection:
Saliva collection device
Requisition form
Pen
Collect the first sample immediately upon waking, before getting out of bed.
Remove the tube cap.
Place the cotton swab from the collection device in your mouth.
Touch the swab as little as possible with your hands.
Leave the swab in your mouth until fully saturated.
DO NOT leave it in longer than 5 minutes.
TIP: Lightly chewing on the swab may help stimulate saliva flow.
Once the swab is saturated, place the swab back into the same tube as you found it.
DO NOT remove the inner tube.
DO NOT spit into the tube.
Complete all information on the tube label.
Freeze the saliva sample until ready to ship.
After you have completed the first collection,
Set a timer for the second and third collections.
Repeat steps 3-8 for each collection.
Your kit has been prepaid. You DO NOT need to pay anything extra.
Since you pre-paid for your tests, you do not need to fill in the payment information on this form.
You must complete your requisition form and send it back with your samples. Failure to complete and send the test requisition form may result in a sample recollection.
Click here for instructions on how to fill out your requisition form.
Failure to complete and send the test requisition form may result in a sample recollection.
Place all devices in the resealable plastic bag.
Place the completed requisition form and samples into the test kit box to ship back to the lab.
If you are in MD, NY, or RI, you must get one of the following documents from your healthcare provider and send it back with your samples:
Written prescription
Lab order on a document with letterhead from the healthcare facility
Please ship your samples as soon as possible after collection.
If you have to wait to ship your samples, please keep all samples in the freezer until you are ready to ship.
To prepare your samples for shipping:
Place the frozen saliva tubes into the test kit box.
Place the test kit box into the provided UPS envelope.
Place the completed requisition form into the provided UPS envelope.
If you are in MD, NY, or RI, place the lab order document from your healthcare provider into the provided UPS envelope.
Seal the envelope.
Make a note of the tracking number so that you can track your sample back to the lab.
Results should be released to your provider 7-10 business days after samples are received at the lab. Rupa Health cannot guarantee processing time.
[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.] 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
[10.] 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.
The DUTCH CAR test provides an analysis of the cortisol awakening response, as well as the daily patterns of free cortisol and cortisone. It also includes the insomnia cortisol sample. This test cannot be ordered for patients under 12 years of age.
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