What to know about parathyroid hormone and osteoporosis

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Osteoporosis is a condition in which bones become weak over time and may break easily. A person may not realize that they have osteoporosis until one of their bones breaks, as there are not any noticeable outward symptoms.

Osteoporosis most commonly affects bones in the hip, wrist, and spine.

The body breaks down old bone tissue and replaces it with new tissue, which helps keep the bones strong. When a person reaches the age of about 30 years, their bone mass stops increasing. From this point, the aim of bone health is to maintain as much bone mass as possible.

By the time a person reaches their 40s and 50s, their bones may consist of more broken down tissue than replaced tissue.

In the bones of a person with osteoporosis, the spaces in the structure of bone tissue widen and become porous. This makes the bones less dense, and the outer shell of the bone thins. The bones become weaker and more brittle, increasing the risk of fractures.

The thyroid gland is a butterfly-shaped gland at the base of the throat near the trachea. The parathyroid glands are four pea-sized glands in the neck near the thyroid.

The parathyroid glands produce hormones called parathyroid hormones (PTH). Through the secretion of PTH, the glands regulate how much calcium:

• the body absorbs from a person’s diet
• the bones store
• the kidneys secrete

If parathyroid glands produce either too much or too little PTH, the balance of calcium will not be right.

If the glands overproduce PTH, a person will develop hyperparathyroidism, and the calcium level in their blood will rise. A benign tumor on a parathyroid gland or the enlargement of a gland can cause it to become overactive. In very rare cases, cancer can cause hyperparathyroidism.

If the parathyroid glands do not produce enough PTH, a person will have hypoparathyroidism. This causes too little calcium in the body and too much phosphorous.

The most common causes of hypoparathyroidism include:

• low levels of magnesium in the blood
• injury to the parathyroid glands
• autoimmune attack on the parathyroid glands
• in rare cases, radioactive iodine treatment for hypothyroidism

If a person has hyperparathyroidism and one of the parathyroid glands overproduces PTH, the hormones signal the constant release of calcium stores from the bone into the blood. This can cause the bones to lose density and structure and become more porous because calcium is what makes bones hard in structure.

This loss of calcium can lead to osteoporosis.

In people with hyperparathyroidism, the bone continues to dissolve and weaken, and osteoporosis causes the risk of breakage to increase. The increased blood levels of calcium may also cause bone pain, which is a common symptom of hyperparathyroidism.

The treatment for hyperparathyroidism usually involves surgery or medication. Doctors may also treat osteoporosis with medication.

Surgery

Surgery is the only sure way to cure hyperparathyroidism. There are different types of surgery for hyperparathyroidism.

Parathyroidectomy is a minimally invasive surgery. A surgeon makes a small incision in the neck and removes the overactive gland. The recovery time is usually short, and a person can typically go home the same day. The surgeon may give a person a regional or general anesthetic during the surgery.

In bilateral neck exploration, the surgeon will make a larger incision to examine all four parathyroid glands and remove the overactive ones. This surgery usually requires general anesthesia, and a person may need to stay in the hospital overnight.

Medication

A doctor may prescribe medication, such as cinacalcet, to people who are unable to have surgery. This medication decreases the amount of PTH that the parathyroid glands make and lowers calcium levels in the blood. However, cinacalcet does not improve bone density.

Osteoporosis treatment

To diagnose osteoporosis, a doctor may perform a bone density scan and develop a treatment plan based on the person’s age and sex, as well as their history of bone breakages and risk of future bone breakages. Treatment will aim to strengthen the bones and prevent fractures.

Medication options may include:

• Selective estrogen receptor modulators (SERMs): These work in a similar way to the hormone estrogen and help maintain bone density, especially in the spine.
• Bisphosphonates: These help maintain bone density by slowing the rate at which the body breaks down bone.
• Parathyroid hormone: Doctors may inject parathyroid hormone treatments to stimulate cells to produce new bone.
• Hormone replacement therapy (HRT): Doctors might prescribe HRT to replace hormones lost during menopause, which can be a factor in the onset of osteoporosis.

If a person does not require medication, a doctor may suggest monitoring the situation and keeping track of bone density.

If a person has hyperparathyroidism, PTH will signal to the bones to release calcium in a constant stream. The loss of calcium from the bones can cause the bones to lose density and become weak and porous. This condition is called osteoporosis.

The most effective treatment for hyperparathyroidism is surgery, which will help slow the loss of bone density. A surgeon may remove one parathyroid gland or open a larger incision to view and remove multiple affected parathyroid glands.

A doctor may prescribe medication if a person cannot have surgery. This treatment can help lower the levels of calcium in the blood, but it will not address osteoporosis. To treat osteoporosis, a doctor may suggest monitoring the person’s bone density, or they may prescribe medication to slow the loss of bone.