Parathyroid Hormone (PTH)

Overview

Parathyroid hormone (PTH) is a peptide hormone produced by the parathyroid glands, located near the thyroid gland in the neck. It plays a crucial role in maintaining calcium balance in the body by regulating the levels of calcium in the blood. PTH is secreted in response to low blood calcium levels and acts on bones, kidneys, and the intestine to increase calcium availability^[1]. Tracking PTH levels is important for diagnosing and managing conditions like hyperparathyroidism and hypoparathyroidism, which can lead to abnormal calcium levels and related health issues^[2].

Scientific Background

PTH is a polypeptide hormone consisting of 84 amino acids, with a molecular mass of approximately 9500 Da^[1]. It is secreted primarily by the chief cells of the parathyroid glands and is regulated by serum calcium levels through a negative feedback mechanism^[1]. PTH influences bone resorption, enhances calcium absorption in the intestine by stimulating vitamin D activation, and increases calcium reabsorption in the kidneys^[1]. Its effects are opposed by calcitonin, another hormone involved in calcium regulation^[1].

Measurement and Testing

PTH levels are typically measured through a blood test, which can be ordered by a healthcare provider to diagnose or monitor conditions affecting calcium balance^[2]. The test involves drawing a blood sample, usually without the need for fasting^[3]. Factors affecting test results include recent calcium intake and kidney function^[2].

Reference Ranges

The normal reference range for PTH varies slightly between laboratories but generally falls between 15 and 65 pg/mL^[5]. Demographic variations, such as age and sex, may influence these ranges, and interpretation should consider concurrent calcium levels^[5]. Elevated PTH levels can indicate hyperparathyroidism, while low levels suggest hypoparathyroidism^[2].

High Values

Elevated PTH levels often result from hyperparathyroidism, where the parathyroid glands produce excessive amounts of hormone, leading to high blood calcium levels^[2]. This can cause symptoms such as bone pain, kidney stones, and fatigue^[4]. Associated health risks include osteoporosis and kidney damage^[4].

Low Values

Low PTH levels are characteristic of hypoparathyroidism, leading to decreased blood calcium levels^[2]. Symptoms may include muscle cramps, tingling, and seizures^[2]. Health risks include impaired bone health and increased risk of seizures due to low calcium levels^[2].

Improving Biomarker Levels

Lifestyle modifications to improve PTH levels include maintaining adequate calcium and vitamin D intake through diet or supplements^[5]. In cases of hyperparathyroidism, surgical removal of overactive glands may be necessary^[4]. For hypoparathyroidism, calcium and vitamin D supplements are often prescribed to manage symptoms^[2].

Importance of Tracking

Monitoring PTH levels is crucial for managing conditions that affect calcium balance, such as hyperparathyroidism and hypoparathyroidism^[2]. Regular tracking helps healthcare providers make informed decisions about treatment and assess the effectiveness of interventions^[3]. It also aids in identifying potential complications early, such as bone disease or kidney problems^[4].

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.