What is Cortisol?
Cortisol is a steroid produced and secreted by the adrenal glands. Cortisol affects many different body systems, including: bone growth, blood pressure control, immune system function, metabolism of fats, carbohydrates, and protein, and nervous system function. Additionally, our brain releases a chemical called adrenocorticotropic hormone in response to threatening stimuli. This triggers your adrenal glands to release cortisol and adrenaline, giving you a burst of new energy and strength.
Let’s take a closer look at cortisol levels:
Cortisol levels follow a pattern called “diurnal variation,” peaking in the early morning then declining throughout the day and reaching the lowest level at night.
Why are cortisol tests performed?
Cortisol tests are done to check for increased or decreased cortisol production, which is an indication of how well the pituitary and adrenal glands are working. Tests may also be ordered when women have irregular menstrual periods and increased facial hair or when children have delayed development and short stature.
More details on the fight or flight response - a modern take:
The fight or flight response which triggers a release of cortisol is a natural and necessary tool for our survival. However, in our modern world threatening situations usually take the form of bills and deadlines not bears and tigers. Our bodies have a limiting response when a threat passes that brings cortisol levels back to baseline; however, when stressors are always present cortisol levels remain elevated. This long-term activation and subsequent overexposure to cortisol and other stress hormones can disrupt almost all of our body’s processes. This puts us at risk for a number of serious health problems, including:
- Anxiety
- Depression
- Digestive problems
- Heart disease
- Weight gain
- Sleep problems
Normally, cortisol levels rise within 10 to 30 minutes of waking to help boost energy levels and then drop throughout the day. This is known as the cortisol awakening response (CAR). In the DUTCH test the 24hr Free Cortisol biomarker is the sum of the Waking, Morning, Afternoon and Night cortisol levels. Cortisol levels are a good indication of baseline HPA axis function since they represent the lowest level during the circadian rhythm. Cortisol is often reflective of glycemic control due to the post-prandial timing of collection. Cortisol measurement reflects peak ACTH-mediated adrenal gland response.
References:
– The cortisol awakening response (CAR): Facts and future directions [L]
– Stress on the dance floor: the cortisol stress response to social-evaluative threat in competitive ballroom dancers. [L]
– Comparison of the cortisol awakening response in women with shoulder and neck pain and women with fibromyalgia. [L]
– Timing the end of nocturnal sleep. [L]
– Enhanced cortisol production rates, free cortisol, and 11β-HSD-1 expression correlate with visceral fat and insulin resistance in men: effect of weight loss [L]
– Awakening cortisol response in lean, obese, and reduced obese individuals: effect of gender and fat distribution. [L]
– Central adiposity and cortisol responses to waking in middle-aged men and women. [L]
– Rise in morning saliva cortisol is associated with abdominal obesity in men: a preliminary report. [L]
– Components of the diurnal cortisol cycle in relation to upper respiratory symptoms and perceived stress. [L]
– A single sleeping midnight cortisol has 100% sensitivity for the diagnosis of Cushing’s syndrome. [L]
– Hyperinsulinemia causes activation of the hypothalamus-pituitary-adrenal axis in humans. [L]
– Cortisol and its relation to insulin resistance before and after weight loss in obese children. [L]
– Hyperthyroidism and cortisol secretion in man. [L]
– Cortisol as a marker for improvement in mindfulness-based stress reduction. [L]
– Daytime napping after a night of sleep loss decreases sleepiness, improves performance, and causes beneficial changes in cortisol and interleukin-6 secretion. [L]
– Cortisol level modulated by integrative meditation in a dose-dependent fashion. [L]
– Effect of Buddhist meditation on serum cortisol and total protein levels, blood pressure, pulse rate, lung volume and reaction time. [L]
– Cortisol decreases and serotonin and dopamine increase following massage therapy. [L]
– Effects of soy lecithin phosphatidic acid and phosphatidylserine complex (PAS) on the endocrine and psychological responses to mental stress. [L]
– The influence of phosphatidylserine supplementation on mood and heart rate when faced with an acute stressor. [L]
– A new view on hypocortisolism. [L]
– Seasonal differences in the diurnal pattern of cortisol secretion in healthy participants and those with self-assessed seasonal affective disorder. [L]
– A blunted cortisol awakening response and hippocampal atrophy in type 2 diabetes mellitus [L]
– Preliminary Evidence for Obesity and Elevations in Fasting Insulin Mediating Associations between Cortisol Awakening Response and Hippocampal Volumes and Frontal Atrophy [L]
– Awakening cortisol responses are influenced by health status and awakening time but not by menstrual cycle phase. [L]
– Sleep disturbances are correlated with decreased morning awakening salivary cortisol. [L]
– Altered cortisol awakening response in posttraumatic stress disorder. [L]
– Enhanced cortisol suppression in response to dexamethasone administration in traumatized veterans with and without posttraumatic stress disorder. [L]
– Hypocortisolism and increased glucocorticoid sensitivity of pro-Inflammatory cytokine production in Bosnian war refugees with posttraumatic stress disorder. [L]
– PTSD symptoms predict waking salivary cortisol levels in police officers. [L]
– Salivary cortisol response to awakening in chronic fatigue syndrome. [L]
– Psychoneuroimmunological correlates of persisting sciatic pain in patients who underwent discectomy. [L]
– Evidence for altered hypothalamus-pituitary-adrenal axis functioning in systemic hypertension: blunted cortisol response to awakening and lower negative feedback sensitivity. [L]
– Basal and stimulated hypothalamic-pituitary-adrenal axis activity in patients with functional gastrointestinal disorders and healthy controls. [L]
– Comparison of the cortisol awakening response in women with shoulder and neck pain and women with fibromyalgia. [L]
– Addison’s disease. [L]
– Comprehensive study of urinary cortisol metabolites in hyperthyroid and hypothyroid patients. [L]
– Low-Serum Cortisol Associated With Opioid Use: Case Report and Review of the Literature [L]
– Low-dose adrenocorticotropin test reveals impaired adrenal function in patients taking inhaled corticosteroids. [L]
– The effect of different doses of isotretinoin on pituitary hormones. [L]
– Cortisol evaluation during the acute phase of traumatic brain injury-A prospective study. [L]
Salivary Cortisol (11AM-1PM)
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