Cortisol (PM):
Why Cortisol (PM) Test?
CLINICAL INFORMATION
Cortisol (also known as stress hormone pumps maximum cortisol under intense stress such as being anxious, emotional stress etc) is a steroid hormone that regulates a wide range of processes throughout the body which includes mainly helping the body respond to stress (during physical stress, excessive cortisol is secreted – i.e strenuous activity, injuries, etc) and also is involved in the regulation of blood pressure (by controlling the salt and water balance), immune response (anti-inflammatory effect, influencing memory formation, fight infections, etc), metabolism (mainly regulating body’s blood sugar levels in carbohydrate metabolism other than fat and protein metabolism), At cellular level (gene transcription factor influencing a multitude of cellular response in all tissues), bone growth, maintenance of vascular tone, CNS function and in pregnancy (development of the fetus) other than its vital role on combating one’s stress response. Almost every cell contains a receptor for cortisol and according to the organs/cell type and/or its receptor type (to where it bends in the body, its action varies in different parts of the body. The adrenal cortex produces glucocorticoids (corticosteroid) that are released into the bloodstream that circulates in the body and when it binds to its receptor manifests its effect. Blood levels of cortisol fluctuate in the body according to time (time-dependent variation), thus there is variation throughout the day, since it has diurnal rhythm as synchronized with the biological clock (i.e it is higher in the morning when we wake up (around 7 AM) and then it falls throughout the day – lowest around midnight), moreover, the timing of cortisol release also depends upon daily activity patterns (eg. For people who work at night, the natural pattern of secretion is reversed when one’s biological clock is altered). Cortisol is regulated by three inter-communicating regions in the body (hypothalamus, pituitary gland, and the adrenal glands hence called hypothalamic-pituitary-adrenal axis). When cortisol level is low in the body, the hypothalamus releases Corticotrophin-Releasing Hormone (CRH) which causes the pituitary to release adrenocorticotropic hormone, into the blood. Thus high levels of Adreno-Corticotropic Hormone (ACTH) in adrenal glands trigger to stimulate cortisol release. When levels of cortisol become higher than necessary, it triggers a feedback mechanism (negative-loop) by blocking the release of CRH. Sometimes in certain disorders/ disease conditions (like Cushing's syndrome – i.e Hyper-Cortisolism, tumors, etc), cortisol levels remain high for a prolonged period of time. Causes of Cushing syndrome include tumors (ACTH producing pituitary gland, tumors of adrenals causing adrenal hyperplasia), rare genetic disorders, damage to hypothalamic-pituitary-adrenal axis, ectopic tumors in the pituitary and/or adrenal glands, severe depression, Immuno-suppressive medications for autoimmune disease (eg. Lupus) and in certain other tumors, etc. Symptoms of Cushing's syndrome include weight gain (fatty tissue deposits in the upper back forming hump-like appearance) in the abdomen, face, and chest but limbs remain slender, flushed round face, high BP, osteoporosis, skin changes ( thining of skin that bruises easily, pink or purple stretch marks called striae), muscle weakness, psychiatric conditions (mood swings, anxiety, extreme stress, depression and/or irritability), libido, diarrhea, constipation, increased thirst with a high frequency of urination, in children it may show delayed physical or cognitive development and in women it causes amenorrhoea, excessive face, and chest hair. While very low levels of cortisol due to pituitary insufficiency and/or acute adrenal crisis in disorders of adrenal gland leads to Addison disease (also called primary adrenal insufficiency is a potentially a life-threatening condition) and its symptoms include chills /fever-like symptoms, fatigue due to extreme weakness, dizziness leading to fainting, (especially upon standing), weight loss due to loss of appetite, muscle weakness, mood changes, darkening of regions of the skin and sudden onset of severe pain in the lower back abdomen or legs. Causes of Addison disease include pituitary gland tumor or that causes underactive pituitary activity that inhibits ACTH production – causing secondary adrenal insufficiency, hypo-pituitarism (absence of signal to trigger adrenal gland to produce a synthesis of cortisol), suppression of normal pituitary or adrenal function by glucocorticoid medications including pills, skin creams, eye drops, inhalers, joint injections, chemotherapy and withdrawal from gluco-corticoid treatments, etc. Cortisol serum test and Urine Cortisol test(also known as urinary free cortisol test or UFC or 24 hours urine cortisol test) helps to enable physicians to screen or confirm certain conditions for diagnosis such as disorders of adrenal gland namely Cushing’s syndrome (production of excessive cortisol in the body), Addison disease (inadequate synthesis of cortisol). Thus this serum cortisol test assists in the diagnosis of medical conditions like Cushing's syndrome, Addison disease, and screens for diseases in differential diagnosis to rule out diseases of the pituitary and adrenal glands. Timing of the test such as Cortisol (PM) test is an important test, like Cortisol (AM) test (since cortisol levels vary throughout the day) to check patient’s abnormal variation of rhythm caused in disturbed diurnal-variation (if the patient has adapted to altered biological clock that reflects in usual normal variation to time of cortisol secretion). Cortisol (PM) testis thus ordered if the physician suspects in case of hyper-cortisolism and hence suggests for this test to check the levels of cortisol at the later part of the day to confirm disturbed diurnal variation and also to screen to diagnose congenital anomalies, Addison’s disease, Cushing’s syndrome, Adrenocortical insufficiency, and its hormone-related disorders. Levels of cortisol in the body can be measured on body fluids such as blood, saliva, and/or urine, so performing in the different specimens can give more accurate results. Certain conditions that interfere with cortisol test results include alcoholism, renal disease (decreased excretion may show low urinary cortisol) medications like diuretics, estrogen, glucocorticoids, ketoconazole, lithium, tricyclic anti-depressants, anti-seizure medicines, HRT such as androgens and/or estrogens like oral contraceptives, steroids - synthetic glucocorticoids medications such as hydrocortisone, prednisone, prednisolone, etc. Additional tests for supporting evidence include ACTH stimulation test, Dexamethasone suppression test, etc. Other tests methodologies include liquid chromatography-tandem mass spectrometry – LC-MS/MS, immunoassays, etc.
General Instructions:
Sample Requirement: Specimen - Blood sample collected from the vein at night. Test Preparation: As guided by the physician.
NOTE - Sample for specimen collections may vary based on the patient’s condition/cases according to patient’s presenting complaints/signs or symptoms:
SPECIMEN REQUIREMENT (Special or Rare Cases) - As instructed and guided by Physician / Clinician / Pathologist / as per Laboratory’s requirements, according to procedures and protocols.
Sample Requirement: Blood Sample taken from the vein at night
Test Preparation: As guided by the physician or the pathologist
This Multi-Specialty Clinical Referral Laboratory RT DIAGNOSTICS provides precise and accurate tests with an extensive range of testing services to the medical centers to help in the diagnosis and identification of pathology in the test specimens for infectious diseases and also to evaluate the function of organ systems of the patient. It prevents further complications and helps to stabilize and restore health to near normalcy at the earliest without delay.
