Osteoporosis is a bone disease that involves a loss of bone density. It causes the bones to become more fragile and prone to fractures. Secondary osteoporosis develops either as a result of a medical condition or as a side effect of a medication.

Osteoporosis affects about 10 million people in the United States. The disease may be primary or secondary. Primary osteoporosis occurs as a result of the natural aging process, whereas secondary osteoporosis occurs due to other reasons.

This article describes the difference between primary and secondary osteoporosis. It also outlines the possible causes of secondary osteoporosis and provides information on the symptoms, diagnosis, and treatment options.

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Doctors categorize osteoporosis into primary and secondary osteoporosis.

Primary osteoporosis is a consequence of the aging process. In females, hormones such as estrogen and progesterone decline after menopause. These hormones are essential for healthy bones, and when their levels are low, the body becomes less able to produce new, healthy bone tissue.

Secondary osteoporosis develops when an underlying medical condition or the use of a certain medication interferes with the body’s ability to produce new bone tissue.

Secondary osteoporosis may develop when certain medical conditions or medications interrupt the formation of new bone tissue. An imbalance between the loss of old bone and the production of new bone leads to a lower bone turnover rate. The result is a loss of bone density.

Medical conditions

Medical conditions that may lead to secondary osteoporosis include:

Medications

In most cases, secondary osteoporosis occurs as a result of taking certain medications, which include those below.

Hormones and medications that affect the endocrine system

The endocrine system is a network of glands that produce and secrete hormones for a wide range of bodily functions. Hormones and other medications that affect the endocrine system may cause secondary osteoporosis. Examples include:

  • thyroid hormone
  • glucocorticoids
  • thiazolidinediones
  • hypogonadism-inducing agents:
    • aromatase Inhibitors
    • medroxyprogesterone acetate
    • gonadotropin-releasing hormone (GnRH) agonists

Medications that affect the immune system

The immune system consists of various organs, cells, and proteins that work together to protect the body from pathogens and toxins. Medications that affect the immune system may cause secondary osteoporosis. Examples include antiretroviral therapy and calcineurin inhibitors.

Medications that act on the central nervous system

The central nervous system (CNS) consists of the brain and spinal cord. Medications that affect the CNS can increase the risk of secondary osteoporosis. These include anticonvulsants and antidepressants.

Medications that affect the gastrointestinal tract

The gastrointestinal tract consists of all the organs involved in the digestive process. Medications that affect the gastrointestinal tract can increase the risk of secondary osteoporosis. An example is proton pump inhibitors, which reduce the production of stomach acid.

People with osteoporosis are usually unaware that they have the condition, as they typically do not experience any symptoms. Often, people only receive a diagnosis of osteoporosis following a bone break from a fall or sudden impact.

The most common injuries associated with osteoporosis are:

  • broken hip
  • broken wrist
  • broken vertebrae

As the bones become increasingly fragile, people may experience fractures in other parts of the body. Seemingly harmless activities, such as sneezing or coughing, can sometimes cause these fractures.

Some older people with the condition may develop a stooped posture due to bone fractures within the spine.

A doctor will perform a thorough medical examination to look for conditions that may cause secondary osteoporosis. They will also take a full medical history to help identify any medications that may be associated with the condition.

Simple screening procedures can help identify possible causes of secondary osteoporosis. These procedures may include:

  • testing blood or other bodily fluids for the following:
    • metabolic bone markers
    • protein
    • electrolytes
    • blood cell count
    • creatinine
    • calcium
    • alkaline phosphates
    • liver enzymes
  • blood tests to assess thyroid function
  • DEXA or ultrasound scans to assess bone density

Various treatment options are available for secondary osteoporosis. A doctor will decide on the best treatment approach on a case-by-case basis. Possible treatment options include:

  • Treating the underlying medical cause: Doctors will prescribe medications or therapies to treat any underlying medical condition that is causing or contributing to secondary osteoporosis.
  • Reducing medication dosages: Doctors may reduce the dosage of any medications that are causing or contributing to secondary osteoporosis. Where possible, they may change the medication entirely.
  • Vitamin D supplementation: Vitamin D is essential for bone health, and a deficiency in this vitamin can cause osteoporosis. A doctor may prescribe vitamin D supplements to help boost the levels of this vitamin in people who have a deficiency.
  • Testosterone replacement: In males, osteoporosis may be associated with low levels of testosterone. Doctors may prescribe testosterone to replenish the levels of this hormone.
  • Treating glucocorticoid-induced osteoporosis: In some cases, medications called glucocorticoids may cause osteoporosis. Doctors may prescribe medications to counteract the effects of these drugs.
  • Bisphosphonates: Bisphosphonates are medications that help strengthen bones and reduce the risk of bone fractures. Doctors may prescribe these medications for people with good kidney function and adequate levels of vitamin D and calcium. Examples of bisphosphonates include:
  • Parathyroid hormone (PTH) antagonists: PTH contributes to the formation of new bone tissue. PTH antagonists include:
  • Weight-bearing exercise: This type of exercise may be helpful in stimulating the formation of new bone.

Osteoporosis is a condition that causes a loss of bone density, making bones fragile and prone to fractures. The condition may be primary or secondary. Primary osteoporosis occurs as a result of the natural aging process. Secondary osteoporosis results from certain underlying medical conditions or the use of particular medications.

Osteoporosis typically does not cause any obvious symptoms. A person may only become aware that they have the condition following a bone fracture from a fall or sudden impact.

A doctor may diagnose secondary osteoporosis using a variety of tests, such as blood tests and bone imaging tests. The treatment for secondary osteoporosis involves identifying and treating the underlying cause. This may involve addressing any underlying medical issues or reducing the dosages of any medications that may be causing or contributing to the disease.