Cortisol

Cortisol is a corticosteroid hormone that is produced and secreted by the human adrenal cortex. This hormone is generally responsible for restoring homeostasis in response to stress. General effects of normal levels of cortisol include elevating blood pressure, elevating blood sugar level, suppressing the immune system with a specific effect on T-cell lymphocytes, enhancing catecholamine activity, enhancing short-term memory, and enhancing bone metabolism. However, irregular levels of this hormone may have detrimental effects.

Cortisol in the serum is mostly found bound to proteins. It is a cholesterol-based hormone and its production depends on the levels of pituitary adrenocorticotropic hormone (ACTH). High levels of cortisol, however, inhibit the production of ACTH by inhibiting corticotropin-releasing hormone (CRH), which forms a negative feedback loop that functions to regulate the serum level of cortisol. Acute levels of cortisol undergo diurnal variations, meaning they change throughout the course of the day, with highest levels in the morning and the lowest at night. Disruption of this cycle can be caused by physical factors or psychological factors.

Clinically used as hydrocortisone, also known as compound F, it is injected into arthritic joints to help treat rheumatoid arthritis. Another common pharmacological use is as a topical cream that reduces skin inflammation or itchiness such as Cortisone-10. It is also used to suppress allergic reactions and is orally implemented.

While these treatments using cortisol derivatives are highly useful, improper levels of cortisol in the body may cause serious conditions. Usually, these syndromes are caused by tumors of the adrenal [Page 168]cortex or the pituitary gland. A highly elevated level of cortisol, hyperadrenocortical syndrome or Cushing syndrome, is usually caused by an adrenal cortex tumor(s) and causes extreme weight gain in the face (“moon face”) and in the trunk, hypertension, susceptibility to pulmonary infections, as well as other effects. Another form of hyperadrenocortical syndrome, Cushing disease, also causes increase levels of cortisol; however, it is caused by tumor(s) in pituitary gland, which in turn causes increased levels of ACTH release. On the contrary, hypocortisolism or Addison's disease is characterized by decreased levels of cortisol by either diseased or damaged adrenal glands or pituitary gland. Results of this imbalance may cause excessive weight loss, muscle weakness, and increased blood acidity.

Cortisol levels are typically elevated in obesity, although circulating concentrations usually appear to be normal. Increased cortisol levels in obesity, particularly in abdominal obesity, may be one source of difference in the metabolic efficiency of lean vs. obese individuals, and high cortisol levels may exacerbate certain disease conditions (e.g., Type 2 diabetes). For this reason, several companies have formulated medications such as CortiSlim to lower cortisol levels in obese individuals. These medications have not proven to be effective.”