Adrenocorticotropic Hormone (ACTH)

Overview

Adrenocorticotropic hormone (ACTH) is a peptide hormone produced by the anterior pituitary gland. It plays a crucial role in the body by stimulating the adrenal glands to produce cortisol, often referred to as the "stress hormone," and other hormones like androgens^[1]. ACTH levels are tracked to diagnose and manage conditions affecting the pituitary and adrenal glands, such as Cushing"s disease, Addison"s disease, and hypopituitarism^[3].

Scientific Background

ACTH is derived from the precursor molecule pro-opiomelanocortin (POMC) and is released in response to corticotropin-releasing hormone (CRH) from the hypothalamus^[1]. It acts through the hypothalamic-pituitary-adrenal (HPA) axis, a feedback system that regulates cortisol levels. High cortisol levels inhibit CRH and ACTH release, while low cortisol levels stimulate their production^[3]. ACTH also influences the production of other hormones and has effects outside the adrenal glands, such as on bone formation^[1].

Measurement and Testing

ACTH levels are typically measured through plasma tests, often in conjunction with cortisol measurements^[4]. Testing may require fasting or dietary restrictions. Since ACTH levels vary throughout the day, with peaks in the morning and troughs in the evening, timing of sample collection is important for accurate interpretation^[4].

Reference Ranges

Normal ACTH levels typically range from 10 to 60 pg/mL, though this can vary slightly depending on the laboratory and the time of day the sample is taken^[2]. Demographic factors such as age and sex may influence these ranges, but generally, they remain consistent across different populations. Interpretation of results requires consideration of cortisol levels and clinical context^[4].

High Values

Elevated ACTH levels can indicate conditions like Cushing"s disease or Addison"s disease^[3]. High ACTH may lead to excessive cortisol production, causing symptoms such as weight gain, hypertension, and mood changes. In Addison"s disease, high ACTH levels result from the adrenal glands" inability to produce cortisol^[1].

Low Values

Low ACTH levels often suggest secondary adrenal insufficiency due to pituitary dysfunction or hypopituitarism^[1]. This can lead to insufficient cortisol production, resulting in symptoms like fatigue, weight loss, and decreased blood pressure. Low ACTH may also be seen in cases of adrenal tumors that autonomously produce cortisol^[3].

Improving Biomarker Levels

Lifestyle modifications such as stress management and adequate sleep can help regulate ACTH and cortisol levels. In cases of deficiency or excess, medical interventions may be necessary, including hormone replacement therapy or surgical removal of tumors^[5]. Supplements like vitamin C and omega-3 fatty acids may support adrenal function, but their effectiveness is variable and should be discussed with a healthcare provider^[5].

Importance of Tracking

Monitoring ACTH levels is crucial for diagnosing and managing conditions related to the pituitary and adrenal glands. It helps healthcare providers make informed decisions about treatment and assess the effectiveness of interventions. Regular tracking can also prevent complications associated with cortisol imbalances^[3].

Disclaimer

The information provided in this document is for educational purposes only and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.