Everything you need to know about Osteoporosis

Osteoporosis is characterized by a loss of bone strength which predisposes to fractures. To find out more, see our detailed fact sheet.

Osteoporosis, what is it?

Osteoporosis is characterized by a loss of bone strength which predisposes to fractures. In most cases, the bones become fragile due to a lack of calcium, phosphorus and other minerals.

Osteoporosis makes bones more porous and more likely to fracture in a trivial fall that would normally have been harmless.

It should be noted that it is not a disease, but a natural process most often linked to aging.

Objective: to prevent fractures

According to guidelines issued by Osteoporosis Canada, physicians should focus on preventing fractures rather than treating osteoporosis at all costs. This new orientation is based on the most recent scientific data.

Indeed, it turns out that osteoporosis is just one of many risk factors for fractures. This means that it is possible to have osteoporosis, but a low risk of fracture. Conversely, it is possible to have a high fracture risk without osteoporosis.

The doctor must therefore carry out an overall assessment of the patient's state of health, the medications he takes, his family history, his lifestyle, etc. Only if he deems it necessary will he offer a bone densitometry test, which measures bone mineral density. Previously, the decision to treat or not was essentially based on the results of this test.

All the data collected is used to establish the probability that a fracture will occur over the next 10 years. Several questionnaires have been developed to allow the doctor to assess this risk. These vary slightly from country to country and have been tested with large sample populations.

Note that a diagnosis of osteoporosis can be issued following one of the following two situations:

an X-ray examination, or bone densitometry test, reveals osteoporosis;
a fracture caused by bone fragility.

When osteoporosis is diagnosed and treated, it is possible to stabilize or improve the condition of the bones to the point of reducing the risk of sustaining a fracture by 50%.

Evolution of bone mass with age

All individuals do not have the same bone “capital”. 3/4 of it is determined by heredity. Good lifestyle habits (exercise, calcium consumption, etc.) help preserve this capital and make it grow.

Maximum peak bone mass is reached around the age of 35 (see diagram below). This is generally maintained for up to 40 years. Thereafter, bone mass tends to decline by 1 to 2% per year.

During the 10 years following the onset of menopause, bone loss accelerates by 2% to 3% per year, due to the decline in estrogen production. The loss then stabilizes at about 1% per year.

In the case of men, the loss is more gradual. From the age of 65, however, their risk of suffering from osteoporosis increases and they are more likely to have fractures.

The following graph gives an idea of the evolution of bone mass with age. This is an average curve. Thus, the curve relating to a particular individual may be different, as it depends on his heredity and lifestyle. To learn about the factors that contribute to the onset of osteoporosis, see the sections People at risk and Risk factors.

Osteoporosis: who is affected?

Most of the time, osteoporosis appears in people aged 65 and over, but it can occur earlier.

It is estimated that in Canada, 1 in 4 women and 1 in 8 men will be affected during their lifetime. From the age of 50 until the end of their life, 4 out of 10 women will experience a fracture due to osteoporosis.

The bones of the hip, wrist and spine are the bones most often fractured due to osteoporosis.

Osteoporosis: possible complications

By trying to limit or prevent bone fractures, we essentially want to avoid the consequences: pain, loss of autonomy, reduced quality of life (especially for hip fracture), etc.

20 to 25% of people who have a hip fracture will die within the next year.

The consequences are often more serious for men who, at the same age, are generally in poorer health than women.

Osteoporosis: symptoms

Osteoporosis usually causes no symptoms, hence its nicknames “silent thief” or “silent evil”. Often, bone loss is not noticed until after a fracture that occurs during a fall.

One of its first symptoms is sometimes a reduction in height (by 4 cm or more). This decrease is linked to a curvature of the back caused by a collapse of the vertebrae. This sagging can lead to severe back pain.

Osteoporosis: people at risk

People over the age of 65;
people who have already suffered a crushed vertebra or a vertebral fracture;
people with a family history of fractures caused by osteoporosis;
people with a disease that interferes with the absorption of calcium in the gut;
women who have had periods of amenorrhea for more than 6 months (excluding pregnancy);
people who have already taken treatment with oral corticosteroids for more than 3 months or anticonvulsant drugs;
to a lesser extent, people with rheumatoid arthritis or who have already had hyperthyroidism. These 2 factors are considered minor;
women who have had an early menopause (before the age of 45), for natural reasons or after the removal of their ovaries.

The production of estrogen, which contributes to the maintenance of bone mass, decreases significantly at menopause. The longer the body is exposed to estrogen, the lower the risk of osteoporosis. Additionally, women who lack estrogen due to a condition called hypogonadism are also at increased risk.

Osteoporosis: preventive measures

The main goal is to prevent fractures. Prevention reduces the risk of fractures associated with osteoporosis by half.

Attention should be given to preventing osteoporosis and fractures from an early age. As mentioned by the World Health Organization (WHO), the earlier you adopt a healthy lifestyle, the better the gains.

Screening measures

The majority of expert groups, including Osteoporosis Canada33, recommend that the following people undergo an in-depth fracture risk assessment by a doctor, as mentioned at the beginning of the sheet:

women and men aged 65 and over;
postmenopausal women potentially at risk, according to the doctor;
men 50 and older potentially at risk, according to the doctor.

In certain special cases, for example in the case of rheumatoid arthritis, screening could be offered before the age of fifty.

Basic preventive measures

The following 3 measures are the most important. It is also a good idea to avoid the risk factors described above as much as possible.

Exercise

Studies show that physical exercise is good for the bones, throughout life. Being active during childhood and adolescence is particularly important, because it allows you to build a more resistant skeleton, therefore to build up reserves of bone mass that will be used in adulthood.

Physically fit people develop better balance and coordination, which reduces their risk of falling.

It is recommended to practice a minimum of 30 minutes of physical activity at least 3 times a week. What matters most is not the duration of the sessions, but their frequency.

Eat calcium-rich foods

Almost every cell in the body needs calcium to function well. Having a diet that contains enough calcium makes it possible to meet the body's needs without having to draw on its reserves, that is to say the bones.

Adequate calcium intake can be obtained by regularly eating dairy products, salmon (with bones), sardines, dark green vegetables (broccoli, etc.), soy products (tofu, soy milk enriched with calcium). To find out if you're getting enough calcium, use our interactive calculator. To find out more, see our Calcium sheet.

Have an adequate intake of vitamin D

This vitamin is vital for healthy bones and teeth. It improves the absorption of calcium in the intestine and participates in the fixation of this mineral in the bones. Its active form is synthesized in the skin when it is exposed to the ultraviolet rays of the sun.

There is little vitamin D in food in its active form, except in fish (sardines, mackerel, herring, salmon, etc.). This is why, in North America, milk and margarine are fortified with vitamin D. Certain cereals and certain rice or soy drinks are also fortified. Consult the Vitamin D sheet for more information.

Everything you need to know about Osteoporosis