Osteoporosis

Osteoporosis is a bone disease which consists of reducing bone mass and disturbing the proper bone tissue architecture. Osteoporosis is the main cause of fractures in postmenopausal women and elderly people. Fractures in the course of osteoporosis are characterized by low-energy injuries, i.e. they may occur in situations which in a healthy person do not cause bone fractures, e.g. as a result of a slight fall, leaning on the hand, or even during changing the body position. Osteoporosis fractures occur most frequently within the neck of the femur, spine and the distal epiphysis of the forearm bone, but may also affect any other part of the body skeleton.

Osteoporosis is called a “silent disease” because its early stages run without any specific symptoms until bone cracks or fractures occur. Gradually increasing osteoporosis pains are often confused with degenerative changes of the spine or rheumatoid disease. Many people believe that osteoporosis is a natural process resulting from the ageing of the body. It is worth noting that osteoporosis can be prevented to a large extent, and in case of its detection, the progress can be inhibited and the risk of fractures reduced.

What does bone strength depend on?

Bone tissue consists of osteocytes (bone cells) and an extracellular substance containing, among others, collagen fibres and mineral compounds of calcium, phosphorus, and magnesium. Collagen and calcium compounds are most important for maintaining optimal elasticity and mechanical resistance of the bone.

Cells in the bone tissue take part in continuous bone remodelling. Osteoclasts are responsible for bone resorption and osteoblasts for the formation of new bone tissue. In childhood and teenage years, bone formation processes prevail over resorption processes, which enables bone growth in length. After this time, the skeleton stops growing but the bone formation processes still prevail, which results in the highest bone mass value in life at the age of twenty plus years. In subsequent periods of life, the bone mass remains constant and then gradually decreases due to the predominance of bone resorption processes. The height of peak bone mass and the rate at which it falls depend on a number of factors, some of which can be influenced to reduce the risk of osteoporosis.

Types of osteoporosis and its causes

Primary osteoporosis

The most common form of osteoporosis is primary osteoporosis (80% of cases). Very important for the development of the disease are:

genetic factors,
vitamin D3 deficiency,
calcium absorption disorders of the gastrointestinal tract,
a fragile body structure,
physiological decline in the level of sex hormones,
inadequate lifestyle (low physical activity, monotonous diet, stimulants).

There are two types of primary osteoporosis:

Postmenopausal osteoporosis

Postmenopausal osteoporosis affects postmenopausal women with a decrease in oestrogen levels. Oestrogen is a female sex hormone produced by the ovaries, the role of which it is, among others, to stimulate bone formation processes. Initial symptoms of postmenopausal osteoporosis usually appear after the age of 40-45 years. The advanced stage of osteoporosis is dominated by fractures of the distal epiphysis of the forearm bone and vertebral body fractures within the spine.

Senile osteoporosis

Senile osteoporosis affects both women and men. Symptoms appear after the age of 70 years. Fractures usually concern the neck of the femur and the spine.

A rare form of primary osteoporosis is the so-called idiopathic osteoporosis, which can occur at any age (also in children). The aetiology of idiopathic osteoporosis has not yet been explained – its direct cause remains unknown.

Secondary osteoporosis

Secondary osteoporosis accounts for 20% of all cases. The causes of secondary osteoporosis include:

Endocrine diseases:

hyperthyroidism,

oestrogen deficiency in women or testosterone deficiency in men,

Diabetes mellitus type I and II,
Rheumatic diseases, e.g. rheumatoid arthritis (RA), ankylosing spondylitis (IBD),
Inflammatory bowel diseases, e.g. ulcerative colitis, Crohn’s disease,
Cancer,
Some medicines:

Antiepileptic drugs
Anticoagulants, e.g. heparin,
Glucocorticosteroids used in the treatment of bronchial asthma and RA,
Medicines used in chemotherapy,

Long-term immobilisation.

Risk factors for osteoporosis

Low peak bone mass is an important factor increasing the risk of osteoporosis in older age. Other osteoporosis risk factors are associated with a too high rate of bone mass loss due to a significant imbalance between bone resorption and bone formation processes. There are risk factors for osteoporosis that can be influenced (determined by our lifestyle) and such that cannot be directly influenced by ourselves.

Lifestyle-independent risk factors are:

Gender

Osteoporosis is more common in women than in men. Women achieve a lower peak bone mass than men. In addition, women are exposed to a higher rate of bone mass loss due to the decrease in oestrogen levels after menopause and in the course of hormonal disorders.

The risk of developing osteoporosis increases with age. A clear advantage of bone tissue resorption begins in women at the age of 40 and men at the age of 50. As a result of continuous bone loss, the mechanical strength of the bone constantly decreases, generating the highest risk of osteoporosis fracture in the elderly.

Body structure

People with a delicate, lean body (ectomorphic type) are more likely to develop osteoporosis.

Race

The white (Caucasian) breed is the most predisposed to develop osteoporosis.

Genetic factors

The susceptibility to osteoporosis can be inherited. People whose parents have been affected by osteoporosis often have abnormally reduced bone mass.

Deficiencies in sex hormones

Women with premature menopause are more likely to develop osteoporosis. Oestrogen deficiency may also occur after surgical removal of the ovaries or as a result of chemotherapy and radiotherapy used to treat reproductive organ cancer. Hormone replacement therapy is a solution for postmenopausal women and women with oestrogen deficiency. Elderly men experience a decrease in testosterone, which can also lead to accelerated development of osteoporosis.

Risk factors depending on the lifestyle:

Nutrition disorders, poor diet

In the reproductive period, oestrogen deficiency may be associated with restrictive weight-loss diets, too low body weight, or competitive sports. The problem of too low oestrogen levels often concerns women engaged in sports, in which it is important to maintain a slim body silhouette (ballet dancers, long-distance runners).

Hunger cures and strict diets can also lead to a shortage of calcium and vitamin D, which increases the risk of osteoporosis. Nutrition during the growth of the body, when the peak bone mass is built up, is of great importance.

Low level of physical activity

A sedentary lifestyle or periods of prolonged immobilization reduce the load on the bone skeleton, leading to reduced osteoblast activity (decrease in bone formation processes) and reduced bone mass.

Alcohol abuse
Smoking

Symptoms of osteoporosis

Early stages of osteoporosis are often asymptomatic. It is only when bone fractures occur that pain and secondary skeletal deformities appear. In osteoporosis patients, deformities of the vertebral bodies occur, which manifest themselves in:

spinal pain that intensifies during movement,
a humped body (rounded back in the region of the thoracic spine),
reduction of body height,
reducing the distance between the ala of the ilium and the costal arch.

As the disease progresses, more serious fractures can occur as a result of minor injuries. The most common are fractures of:

the neck of the femur – as a result of a fall on the hip,
the spine – during sudden bending, straightening or turning of the torso,
the distal epiphysis of the forearm bone – due to leaning on the wrist.

Further development of osteoporosis leads to spontaneous fractures, which occur even in consequence to a slight change in body position or for no apparent reason.

Diagnostics of osteoporosis

Who should consult a physician to assess the risk of osteoporosis?

People who have had a low-energy fracture, regardless of their age,
Persons over 50 years of age who have suffered a broken bone at least once in their lifetime,
Women over 65 years of age (even without experienced fractures),
Premenopausal women with menstrual disorders,
People who have noticed a loss of body height, a humped back and started to feel back pain,
People taking steroid drugs (glucocorticosteroids) for at least 2 months,
Persons suffering from chronic diseases of the digestive system,
Persons with BMI < 20 kg /m2,
People with anorexia, bulimia.

The physician decides on the basis of an interview whether it is necessary to broaden the diagnosis of osteoporosis.

Densitometric examination

The basic type of osteoporosis tests is densitometry using the DEXA technique (dual-energy X-ray absorptiometry). Densitometry allows evaluating bone mineral density. The examination is performed with the use of an apparatus which emits small amounts of X-rays. During the diagnosis, the patient lies on a special table and the device x-rays the bone tissue of a given area of the body – usually the proximal femoral epiphysis or lumbar spine. Densitometry is a completely painless examination and does not require special preparation.

The results are presented in the form of indicators, which compare the bone mineral density of the examined person with the bone density of the healthy population (T-score) and people in the same age group (Z-score).

FRAX calculator

The FRAX Calculator is a publicly available form that can be used to assess the risk of osteoporosis fracture over the next 10 years. The FRAX calculator takes into account the risk factors of osteoporosis and the result of the densitometric examination (although it is not absolutely necessary to have the latter). The form for the Polish population is available here.

Imaging studies

X-rays can only show advanced osteoporosis, which is why they are not used for diagnostic purposes. X-ray examination is, however, necessary in the case of suspected osteoporosis fracture. Similarly, computed tomography or magnetic resonance imaging are mainly helpful in the assessment of the fracture type and in the planning of a surgical procedure.

Laboratory tests

Blood and urine are collected for testing. Most frequently evaluated parameters in the diagnostics of osteoporosis are:

Phosphates and total calcium in blood serum,
Daily excretion of calcium in urine,
Vitamin D – determined in the results as 25(OH)D,
Parathyroid hormones (parathormone),
ALP (alkaline phosphatase) – an enzyme which plays a role in the process of bone mineralization.

Prevention of osteoporosis

In order to reduce the risk of developing osteoporosis, it is worth taking care of your bones throughout your life. In order to do so, it is necessary to:

exercise regularly,
eat products rich in calcium and vitamin D,
stop smoking,
reduce alcohol consumption.

Physical activity

Young people with regular physical activity reach a higher peak bone mass than those with sedentary lifestyles. The best form of exercise are exercises or activities with a load of own body weight and resistance exercises with instruments. The effort should be taken every day for about 30 minutes. Examples of recreational sports worth practising are walks, Nordic Walking, dancing, tennis, jogging. In case of health problems (e.g. heart disease, hypertension, diabetes), it is necessary to consult an orthopaedic surgeon or physiotherapist in order to choose a safe form of activity.

Adequate diet

Insufficient calcium supply in the diet may lead to the development of osteoporosis. Between 9 and 18 years of age, the daily calcium intake in the diet should be 1300 mg, and in people over 19 years of age 1000-1300 mg depending on gender (postmenopausal women require higher calcium intake). The final calcium requirement should be determined by a physician or clinical nutritionist. In order to provide your body with the right amount of calcium, you should regularly consume products such as:

fish (sardines, salmon),
eggs,
cottage cheese,
natural yoghurt,
milk.

Lack of the required amount of vitamin D in the body may contribute to disturbances in calcium absorption in the gastrointestinal tract and its secondary deficiency. Approximately 80% of vitamin D is produced in the skin under the influence of sunlight, while the remaining 20% comes from food sources. In Poland, due to the periodical lower exposure to sunlight (autumn, winter), many people may be exposed to insufficient vitamin D supply. The sources of vitamin D in food are mainly milk, dairy products and fish. Calcium and vitamin D supplements are particularly recommended for people who spend most of their time in closed rooms and people with lactose intolerance who give up eating milk products.

Treatment of osteoporosis

Treatment of osteoporosis should be comprehensive and conducted under the strict supervision of a physician, physiotherapist, and dietician. The aim of osteoporosis treatment is to limit bone resorption processes, stimulate bone tissue structure processes and prevent falls which are the main cause of osteoporosis fractures.

Appropriate supply of calcium and vitamin D

In the treatment of osteoporosis, diet alone is often not enough, therefore, it is worth taking dietary supplements containing calcium and vitamin D. During the supplementation control tests should be performed (concentration of calcium and vitamin D in the blood and the level of excreted calcium in the urine).

Physiotherapy

Properly directed exercises conducted under the supervision of a physiotherapist allow for the improvement of:

body posture,
stability of the body and equivalent reactions,
strength and resistance of the muscles.

Physiotherapy reduces the risk of bone fractures by learning active trunk stabilization, safe body position changes, and strategies to prevent falls. Allowed forms of recreational activity are quiet exercises in the pool and riding a stationary bicycle with minimal resistance. The final choice of exercises and activities depends on the level of osteoporosis, age, and diseases accompanying the patient.

Drugs for osteoporosis

Treatment of osteoporosis also includes the use of drugs the action of which reduces the risk of bone fractures. Some drugs stimulate the bone formation process, others inhibit the process of excessive bone resorption. Drugs used in the treatment of osteoporosis include, among others:

biphosphonates,

strontium ranelate,
salmon calcitonin,
hormone replacement therapy.

The choice of pharmacological therapy belongs to the responsibilities of the attending physician.

References:

FAQ

What is osteoporosis?

Osteoporosis is a metabolic bone disease that involves a gradual loss of bone mass. The essence of the disease is an excessive advantage of bone resorption processes over the processes of creating new bone tissue. Osteoporosis leads to a decrease in the mechanical strength of the bone, thus significantly increasing the risk of fractures. Osteoporosis fractures occur as a result of a minor injury, e.g. as a result of leaning on a hand or a fall from the standing position. Osteoporosis may result from an inadequate diet, sedentary lifestyle, hormonal disorders, co-morbidities, and chronic use of certain drugs.

Does osteoporosis hurt?

Early stages of osteoporosis are often asymptomatic. It is only when bone rupture or fracture occurs that pain in the spine and long bones occurs. Gravity and high weight of the body lead to deformations of the vertebral bodies, which is manifested by changes in the body shape – reduction in body height and rounding of the back in the thoracic section of the spine.

How does an osteoporosis test look like (densitometry)?

Densitometry allows evaluating bone mineral density. The examination is performed with the use of an apparatus which emits small amounts of X-rays. During the diagnosis, the patient lies on a special table and the device x-rays the bone tissue of a given area of the body – usually the proximal femoral epiphysis or lumbar spine. Densitometry is a completely painless examination and does not require special preparation. The results are presented in the form of indicators, which compare the bone mineral density of the examined person with the bone density of the healthy population (T-score) and people in the same age group (Z-score).

What to eat in case of osteoporosis?

The diet in osteoporosis patients should be well balanced, adjusted to age, gender, and the degree of deficiency of certain ingredients shown by laboratory tests. Particular attention should be paid to covering the need for protein, calcium, and vitamin D, which build up the bone tissue or influence its metabolism.

How to treat osteoporosis?

The choice of treatment methods for osteoporosis depends on the possible cause of its occurrence. In most cases, the treatment is complex and encompasses:

taking drugs inhibiting bone mass loss,
rehabilitation in the form of safe exercises improving posture and reducing the risk of falling,
dietary treatment,
calcium and vitamin D supplementation,
reduction of risk factors (quitting smoking, giving up alcohol).

Hormone replacement therapy is used in women after menopause or with oestrogen deficiency. The treatment plan is established by the attending physician after thorough diagnostics, taking into account the assessment of osteoporosis progression and individual health conditions of the patient.