All you may need to know about osteoporosis

Osteoporosis

1. What is osteoporosis?

2. What are the risk factors of osteoporosis?

3. What are the clinical manifestations of osteoporosis?

4. How is osteoporosis diagnosed, and how are its risk factors evaluated?

5. How is osteoporosis prevented and treated? 


1. What is osteoporosis?

Being one of the most common diseases in the skeletal system, osteoporosis is a systematic disease feature low bone mass, destruction of micro-structures of the bone, increased bone fragility and tendency of fracture.

Microscopic images of normal and porotic bones, source: WebMD


Osteoporosis can happen in each gender and age, but more frequently in women after menopause and men in old age. Some diseases & medications that affect the metabolism of bones can also cause osteoporosis.

One serious consequence of osteoporosis is fracture, which can be caused by minor injuries or even activities in everyday life.


2. What are the risk factors of osteoporosis?

Major risk factors of osteoporosis include: 

1) Race: The Caucasians and Asians are statistically at a higher risk for osteoporosis than the African.

2) Old age: Osteoporosis is a degenerative disease, so its risk increases as the age grows.

3) Menopause

4) Life style: nicotine use, alcohol abuse, lack of physical activities, unbalanced diet (over sufficiency or deficiency of protein, high sodium, deficiency of calcium & vitamin D)

5) Others: underweight, diseases & drugs that affect bone metabolism


3. What are the clinical manifestations of osteoporosis?

The typical clinical manifestations of osteoporosis include pain, deformation of the spine and osteoporotic fracture.

Deformation of the spine in different stages of osteoporosis, source: WebMD


Locations of osteoporotic fracture, source: WikipediaStatistically, after the age of 50, 1/3 of women can experience fracture, so as 1/5 of men (IOF, International Osteoporosis Foundation). The most frequent sites of fracture are the spine, the hips and the distal forearms. The osteoporotic fracture can either cause death due to various complications, or damage the life quality of survivors.


4. How is osteoporosis diagnosed, and how are its risk factors evaluated?

Osteoporosis can be diagnosed by the loss of bone mass, decrease in bone mineral density and/or occurrence of fracture. The bone mineral density (BMD) measurement is an objective and quantified index for the diagnosis of osteoporosis and evaluation on the progression state of the disease.

BMD refers to the bone mass in a volume or space unit. It can be measured with many in-vitro techniques, including dual energy X-ray absorptiometry (DXA), peripheral DXA, quantitative computed tomography (QCT) and quantitative ultrasound (QUS), and etc.

The measurement result of BMD is often written as the T-score. When the T-score is 2.5 times SD (standard deviations) lower than the reference value, a diagnosis of osteoporosis can be made.

FRAX®, a handy prediction tool recommended by the WHO, can be applied to calculate the probability of the occurrence of hip fractures and other major osteoporosis related factures in 10 years.


5. How is osteoporosis prevented and treated?

It is worth noting that osteoporotic fracture is preventable and treatable. Early prevention measures can avoid the occurrence of osteoporosis and fracture; even though a fracture is experienced, proper treatment can still effectively lower the risk of another fracture.

For those with risk factors of osteoporosis but have not met the diagnosis standards, prevention is even more cost-effective, and thus more important. For those who are diagnosed with osteoporosis, or with a T-score below -2.5, or have experienced fracture, the aims of prevention and treatment is to avoid fracture, or a second fracture.

A comprehensive prevention and treatment strategy of osteoporosis can comprise general management, pharmacological interventions and recovery work-ups.

1) General management

a. Life style adjustment: a nutritional and balanced diet, sufficient sunlight, regular sport, refusal to nicotine, limitation in alcohol use, protective precautions against falls;

b. Supplements for bone health: calcium, vitamin D.

2) Pharmacological interventions

For those who have met the standards for pharmacological interventions, for example, osteoporosis patients, patients of low BMD and/or with FRAX® results over the threshold, many pharmacological products can be adopted to intervene through different working mechanisms, such as bone resorption inhibition and bone formation promotion. There are also drugs that work through multiple mechanisms.

It helps with the evaluation of drug efficacy to regularly follow the change of BMD in central bones in every 6-12 months.

3) Recovery work-ups

Sport is one of the successful measures to keep the bones healthy. In each phase of life, sport can help the bones in its own way. For children sport can help increase the bone mass; for adults, to keep the bone mass; for the elderly, to cut down the bone mass loss. A work-up plan for osteoporosis recovery shall emphasize two aspects: to increase BMD and to avoid falls.