What is the function of cortisol in the body?

From the Guidelines

Cortisol is a steroid hormone produced by the adrenal glands that plays a crucial role in regulating metabolism, stress response, inflammation, blood pressure, sleep-wake cycles, and immune function, with its levels carefully regulated by the hypothalamus and pituitary gland to maintain overall health. The function of cortisol in the body is multifaceted, including:

• Regulating metabolism by controlling the use of carbohydrates, fats, and proteins
• Increasing blood sugar when needed by stimulating glucose production in the liver
• Reducing inflammation throughout the body, which is why synthetic versions are used as anti-inflammatory medications
• Maintaining blood pressure
• Regulating sleep-wake cycles following a daily rhythm (highest in the morning, lowest at night)
• Supporting proper immune function According to the most recent evidence 1, cortisol plays a vital role in the body's response to stress, and its imbalance can lead to significant health problems, such as Cushing's syndrome or Addison's disease. The body's regulation of cortisol is complex, involving a feedback system with the hypothalamus and pituitary gland, as described in 1 and 1. It is essential to maintain balanced cortisol levels, and any imbalance can have severe consequences on morbidity, mortality, and quality of life. In cases of cortisol imbalance, treatment options are available, including glucocorticoid replacement therapy, as discussed in 1 and 1. Overall, cortisol is a vital hormone that plays a central role in maintaining the body's homeostasis, and its regulation is crucial for overall health and well-being.

From the FDA Drug Label

Acting primarily through the hypothalamus a fall in free cortisol stimulates the pituitary gland to produce increasing amounts of corticotropin (ACTH) while a rise in free cortisol inhibits ACTH secretion. Normally the HPA system is characterized by diurnal (circadian) rhythm Serum levels of ACTH rise from a low point about 10 pm to a peak level about 6 am. Increasing levels of ACTH stimulate adrenocortical activity resulting in a rise in plasma cortisol with maximal levels occurring between 2 am and 8 am.

The function of cortisol in the body is to be part of the hypothalamic-pituitary-adrenal (HPA) axis, where it plays a role in the body's response to stress and has a diurnal rhythm with levels varying throughout the day. Cortisol helps to regulate the body's metabolism, immune response, and response to stress. It also helps to regulate the body's circadian rhythm. 2

From the Research

Function of Cortisol in the Body

• Cortisol, a stress hormone, plays a crucial role in regulating metabolic, hemodynamic, inflammatory, and behavioral processes 3, 4, 5.
• Its secretion is governed by the hypothalamic-pituitary-adrenal axis, which senses changes in the external and internal environment that may disrupt the homeostatic balance of the organism 5.
• Cortisol affects metabolic, cardiovascular, and central nervous systems both acutely and chronically, and its chronic exposure is associated with insulin resistance and visceral obesity, both significant contributors to metabolic syndrome 3, 4.
• The hormone is synthesized in the adrenal cortex and released into the circulation in a pulsatile and circadian pattern, with its secretion triggered by the release of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from the hypothalamus 5.

Regulation of Cortisol

• The hypothalamic-pituitary-adrenal (HPA) axis comprises the hypothalamus, pituitary, and adrenal glands, and is the major endocrine stress axis of the human organism 4, 5.
• The axis is regulated by a negative feedback mechanism, which can be disrupted by chronic stress exposure, leading to changes in physiological and psychological performances, and increased risk for various somatic diseases 6.
• Cortisol responsiveness is an important determinant in the metabolic sequelae to stress, and individuals with high cortisol responsiveness may be more prone to obesity and metabolic disorders 7.

Effects of Cortisol on the Body

• Cortisol increases the consumption of foods enriched in fat and sugar, and can lead to weight gain and obesity, particularly in individuals with high cortisol responsiveness 7.
• Chronic exposure to excessive cortisol can result in detrimental metabolic effects, including insulin resistance and visceral obesity, and can also affect the central nervous system, leading to changes in behavior and mood 3, 4.
• Oxytocin, a neuropeptide, may have a beneficial effect on adrenal gland function and cortisol regulation, particularly in conditions accompanied by high glucocorticoid levels, such as chronic stress exposure 6.