Osteoporosis: A brief overview
Osteoporosis is a condition which is characterised by loss of calcium and other minerals from the bone matrix leading to weakened bones and fractures after trivial trauma. Although osteoporosis affects both men and women, fractures due to osteoporosis are twice more common in women than men.
The bones in our body are constantly changing. Every day old bone is broken down and new bone produced. During childhood and early adulthood the net increase in bone mass is positive and the peak bone mass is achieved by 30 years of age. From here on the balance of bone formation and resorption tip in to negative and there is a constant loss of bone mass. This rate of loss is increased in women after menopause as the beneficial effect of estrogen on the bone is lost and osteoporosis ensues.
Although osteoporosis affects men as well, it affects many more women, probably because women have less bone mass to start with. Worldwide millions of women are affected by osteoporosis and it is the most commonest cause of fracture in women over 50 years of age. Although the exact cause of osteoporosis is not clear, many risk factors are known to increase the risk of osteoporosis. These risk factors can be broadly divided into modifiable and non-modifiable.
Non modifiable factors
- Sex: Women are twice more likely to suffer from osteoporosis than men.
- Age: Osteoporosis is a disease which predominantly affects people over 55 years of age. The older one gets the more are the risks of developing osteoporosis.
- Race: Whites and people of Asian descent are more likely to develop osteoporosis.
- Family history: Having a parent or sibling with osteoporosis puts you at greater risk, especially if you also have a family history of fractures.
- Frame size: Men and women who are exceptionally thin (with a body mass index of 19 or less) or have small body frames tend to have a higher risk because they may have less bone mass to draw from as they age.
- Thyroid hormone: Excess of thyroid hormones as seen in hyperthyroidism can lead to osteoporosis.
- Medical conditions and procedures that affect bone health: Stomach surgery (gastrectomy) and weight-loss surgery can affect your body's ability to absorb calcium. So can conditions such as Crohn's disease, celiac disease, hyperparathyroidism and Cushing's disease — a rare disorder in which your adrenal glands produce excessive corticosteroid hormones.
Modifiable risk factors
- Low calcium intake: A lifelong lack of calcium plays a major role in the development of osteoporosis. Low calcium intake contributes to diminished bone density, early bone loss and an increased risk of fractures.
- Tobacco use: The exact role tobacco plays in osteoporosis isn't clearly understood, but researchers do know that tobacco use contributes to weak bones.
- Eating disorders: Women and men with anorexia nervosa or bulimia are at higher risk of lower bone density.
- Sedentary lifestyle: People who spend a lot of time sitting have a higher risk of osteoporosis than their more-active counterparts. Any weight-bearing exercise is beneficial for your bones, but walking, running, jumping, dancing and weightlifting seem particularly helpful for creating healthy bones.
- Excessive alcohol consumption: Regular consumption of more than two alcoholic drinks a day increases your risk of osteoporosis, possibly because alcohol can interfere with the body's ability to absorb calcium.
- Corticosteroid medications: Long-term use of corticosteroid medications, such as prednisone, cortisone, prednisolone and dexamethasone, is damaging to bone. These medications are common treatments for chronic conditions, such as asthma, rheumatoid arthritis and lupus, and you may not be able to stop taking them to lessen your risk of osteoporosis. If you need to take a steroid medication for long periods, your doctor should monitor your bone density and recommend other drugs to help prevent bone loss.
- Other medications: Long-term use of aromatase inhibitors to treat breast cancer, the antidepressant medications called selective serotonin reuptake inhibitors (SSRIs), the cancer treatment drug methotrexate, some anti-seizure medications, the acid-blocking drugs called proton pump inhibitors and aluminum-containing antacids are all associated with an increased risk of osteoporosis.
Osteoporosis per se has no symptoms of itself. Initially as the bone loss begins women may not feel any complaints, but as the disease progresses, women may start complaining of vague back aches and joint pains. This due to the weakness of the bones. As osteoporosis advances, bones become completely demineralised and at this fractures are common with even trivial trauma and falls. The most commonly fractured bones include the spine, hips and wrist.
Hip joint is the most commonly affected bone in osteoporosis. This is mainly because hips are the major weight bearing joints of our body. These bones typically fracture after trivial falls or twisting injury to the feet. Women may also fracture their wrists in a fall. The bones of the spinal column can fracture spontaneously and is called as a compression fracture. Compression fractures of the spine are very painful and require a long time to heal. Multiple compression fracture may lead to loss of height and a stooped posture.
Osteoporosis can cause fracture of any bone other than those mentioned above. Other commonly fractured bones are the ribs, the long bones of the leg and pelvic fractures.
Since Osteoporosis is so common a few guidelines on screening for this disease has been developed. The following categories of people are at a higher risk of osteoporosis and may benefit from screening for osteoporosis.
- A woman older than age 65 or a man older than age 70, regardless of risk factors
- A postmenopausal woman with at least one risk factor for osteoporosis
- A man between age 50 and 70 who has at least one osteoporosis risk factor
- Older than age 50 with a history of a broken bone
- Take medications, such as prednisone, aromatase inhibitors or anti-seizure drugs, that are associated with osteoporosis
- A postmenopausal woman who has recently stopped taking hormone therapy
- A woman who experienced early menopause
The diagnosis of osteoporosis is done by a combination of history, X-Rays and DEXA scan. When you first visit the doctor, he is likely to ask a few questions about any complaints you have. Try to mention all complaints you have even if you consider them to be irrelevant. The doctor will also ask you about any previous fractures, medical conditions, and medication use and calcium supplements. Although not much is found in a physical exam, the doctor is still likely to give you a general exam including checking your B.P.
There are two major investigations available for diagnosis of osteoporosis. X-Ray will detect changes of osteoporosis in form of demineralisation of the bone. In late osteoporosis, the X-Ray appearance shows mineralised and demineralised bone alternating. These are called as looser’s zones and are diagnostic of osteoporosis.
Dual energy X-ray absorptiometry
The best screening test is dual energy X-ray absorptiometry (DXA). This procedure is quick, simple and gives accurate results. It measures the density of bones in your spine, hip and wrist — the areas most likely to be affected by osteoporosis — and it's used to accurately follow changes in these bones over time.
Other tests that can accurately measure bone density include:
- Quantitative computerized tomography (CT) scanning
- Single-photon absorptiometry