What is osteoporosis?

Osteoporosis occurs when your bones become brittle and are more easily fractured. It is more common in women, particularly after menopause when oestrogen levels are low, as oestrogen helps maintain bone mass.

Oestrogen

One of a group of steroid hormones involved in the development and maintenance of female sex characteristics. These are the primary female sex hormones.

Causes

Normally your bones undergo a constant cycle of remodelling. The two stages of this remodelling are bone resorption, in which bone is broken down, and bone formation, in which it is created. The two are normally kept in balance, but in osteoporosis the breakdown of bone occurs faster than the creation of it. This imbalance in the cycle of bone remodelling occurs as a result of menopause and ageing, as well as from a range of conditions.

osteoporotic femur, healthy bone compared to bone with osteoporosis, effects of osteoporosis on bone.Visual appearance of osteoporotic bone.  

Risk factors

Family history

If you have a family history of osteoporosis, you have a greater chance of developing it.

Calcium and vitamin D levels

Low calcium and vitamin D levels can lead to osteoporosis. Vitamin D is important for the absorption of calcium. 

Medical history

Conditions such as hyperthyroidism, Cushing's syndrome, premature menopause, chronic kidney disease or liver failure can predispose a person to osteoporosis. Other conditions such as coeliac disease or inflammatory bowel disease, which impair absorption of calcium or vitamin D, can also increase the risk of developing osteoporosis. 

Medications

Certain medications, such as corticosteroids or medications used to treat breast cancer, prostate cancer, epilepsy and depression can increase your risk of osteoporosis. 

Lifestyle

Smoking, drinking excessive alcohol and lack of exercise can increase your risk of getting osteoporosis. 

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

Corticosteroids

A medication that resembles the cortisol hormone produced in the brain. It is used as an anti-inflammatory medication.

Inflammatory bowel disease

A group of conditions characterised by chronic, episodic inflammation of the bowels, including Crohn's disease and ulcerative colitis.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Epilepsy

A common nervous system condition marked by a tendency for recurrent seizures.

Signs and symptoms

There are usually no obvious symptoms of osteoporosis until it causes a fracture, which is why it is sometimes referred to as a silent disease. Collapse of the vertebrae in the spine is the hallmark of osteoporosis.

Fracture

A complete or incomplete break in a bone.

Vertebrae

The bones that make up the spinal column.

Spine

The bony structure that comprises the individual vertebrae that enclose and protect the spinal cord and nerves located in the middle.

Methods for diagnosis

Bone density testing

The following bone density tests can be used to detect a loss of bone strength in people who might not have symptoms, or to monitor the effects of treatment for bone disease:

Dual-energy X-ray absorptiometry

Dual-energy X-ray absorptiometry (DEXA) is a special type of scan that uses low-dose X-rays. Depending on the size of the bone being measured, you may need to lie down in a large machine.

Standard measurements are usually taken from the spine and hip, and a measurement of bone density is given. The readings are usually given in three ranges - normal for age, mildly lower than expected for your age (osteopaenia), or significantly lower than expected for your age (osteoporosis).

Diagnosis of osteoporosis, imaging for osteoporosis.DEXA imaging. 

Quantitative computerised tomography

Quantitative computerised tomography can determine bone density of the spine, but it is not regularly used, as it uses a higher radiation dose than DEXA and is more expensive.

Ultrasound

Ultrasound is sometimes used to measure bone density in the heel bone when DEXA is not available.

Computerised tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.

Radiation

Energy that is emitted, such as heat, light, or energy in electromagnetic waves. Different types of radiation can be used to diagnose and treat disease.

Ultrasound

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Spine

The bony structure that comprises the individual vertebrae that enclose and protect the spinal cord and nerves located in the middle.

Types of treatment

Depending on your circumstances, your doctor will recommend the most suitable osteoporosis treatment for you. This may depend on the underlying cause, whether you are male or female and any side effects you may have had to previous treatment. If you are female, your menopausal status will be taken into account.  

Lifestyle

Modification of lifestyle factors is recommended to improve treatment outcomes. Quitting smoking, reducing your alcohol intake, meeting your recommended daily intake of calcium, maintaining a healthy body weight and exercising regularly can all help slow the progress of osteoporosis. 

Bisphosphonates

Bisphosphonates are a type of antiresorptive medication, which means that they block the breakdown of bone. They include alendronate, ibandronate, risedronate and zoledronic acid. 

Other antiresorptive medications

Raloxifene

Raloxifene is a selective oestrogen receptor modulator (SERM), which can be used in postmenopausal women to help prevent or treat osteoporosis. 

Denosumab

Denosumab reduces bone resorption by blocking the activation and function of cells called osteoclasts, which normally resorb bone. 

Calcitonin

Calcitonin is a hormone that is produced by the thyroid gland. For the treatment of osteoporosis, it is administered by injection or a nasal spray. It is usually only used for postmenopausal women who do not respond to other treatment. It is not widely used any more, due to other more effective medications.

Hormone replacement therapy

Hormone replacement therapy (HRT) is not recommended as a main treatment of osteoporosis by authorities in Australia, which is contrary to international menopause recommendations. HRT programs contain oestrogen, which can help to reduce bone loss and prevent fractures in postmenopausal women. The response to treatment is dose-dependent and even small doses can have a beneficial effect in preserving bone density. 

Anabolic medications

Anabolic medications, such as teriparatide, increase bone formation. They build bone, as opposed to antiresorptive medications, which prevent it from being broken down.

Vitamins and minerals

Your doctor will assess your individual need for calcium and vitamin D supplements. Calcium is only required if your dietary intake is not adequate for your age and menopausal status. Vitamin D levels can be measured with a blood test and if low, a daily oral dose of vitamin D may be recommended.

Anabolic

Anabolic refers to anabolism, which is the process of making complex molecules in living organisms.

Bisphosphonates

A group of drugs that prevent the loss of bone mass by reducing the normal turnover of bone. They are used to treat osteoporosis and other bone diseases.

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.

Cells

The fundamental unit of life; the simplest living unit that can exist, grow, and reproduce independently. The human body is composed of trillions of cells of many kinds.

Fractures

A complete or incomplete break in a bone.

Hormone

A chemical substance secreted in one part of an organism and transported to another part of that organism, where it has a specific effect.

Oestrogen

One of a group of steroid hormones involved in the development and maintenance of female sex characteristics. These are the primary female sex hormones.

Thyroid

A large gland located in the lower front part of the neck that produces hormones that regulate metabolism, growth and development, especially during childhood.

Vitamin D

A vitamin that is important for the health of bones and teeth as it promotes absorption of calcium from the diet.

Postmenopausal

The stage in a woman's life where she no longer experiences menstruation. This is usually defined as occuring 12 months after her last period/menses.

Potential complications

The main complications of osteoporosis are bone fractures, particularly of the hip and spine. Hip fractures may result from a fall and often require surgery. Hip fractures can lead to ongoing disability and potentially death.

Spinal fractures are common and can occur even without injury. They can accumulate over time, causing you to hunch over and become shorter (known as kyphosis).

Treatment options can cause a wide range of side effects, such as heartburn and gastritis, pain in bones and joints, and rarely, damage to the jaw bone. 

However, your doctor will usually closely monitor you while you are on these treatments to detect any side effects. If any are present, your dose or medication can be changed. Talk to your doctor or pharmacist to find out about the possible side effects of the medications you are currently taking. 

Fractures

A complete or incomplete break in a bone.

Spine

The bony structure that comprises the individual vertebrae that enclose and protect the spinal cord and nerves located in the middle.

Prognosis

Treatment helps slow the progression of osteoporosis. Monitoring how you respond to treatment takes the form of a DEXA scan every one to two years. Treatment outcomes vary from person to person, but in general, the earlier you start treatment the better.

Prevention

If you are at high risk of developing osteoporosis, treatment can help prevent the onset of disease. Not smoking or drinking to excess, meeting your recommended daily intake of calcium, maintaining a healthy body weight and exercising regularly all help lower your risk. 

Calcium

A chemical element, important for many biological functions. Particularly central to maintaining bone and tooth health.