What is osteoporosis?
The name osteoporosis comes from "osteo" meaning "bone" and "porosis" meaning "porous". This etymology is explained by the alteration of bone mass and structure. These two aspects reduce bone strength and make the bone weak and fragile. The risk of fractures is then increased. Bone loss occurs silently, asymptomatically.
The most affected people are those over 65 years of age, although osteoporosis may occur earlier. After age 50, the number of women with osteoporosis increases significantly: at age 65, 39% of women have osteoporosis; at age 80, 70% of women have osteoporosis and of these, 60% have at least one fracture. Contrary to popular belief, men are not spared from this disease, even though they are half as affected as women.
Making the diagnosis
When the doctor suspects osteoporosis, they conduct an interview and analyses the patient's risk factors for osteoporosis. They must also check that there are no other causes (tumour, trauma, etc.). When a risk or history exists, the doctor prescribes an imaging test called a "bone densitometry" that gives the Bone Mineral Density (BMD). It is usually performed at two locations: lumbar spine and femur. Depending on the intensity of the difference between BMD and normal, osteopenia or osteoporosis is referred to as osteopenia when bone loss is more severe.
Fractures, the main complication of osteoporosis
The most frequent and severe complications are fractures. They most often reach the spine and hips, which are bones that are under pressure to support weight. Hip fractures, which occur after a fall, can lead to disability and often even death from post-operative complications (prolonged immobilisation).
Fractures are sometimes spontaneous: the vertebrae are then so weakened that they compress and collapse on their own. These fractures cause severe pain, which slowly fades away. The succession of these subsidences leads to a curved back.
Preventable risk factors
Alcohol and tobacco: excessive consumption of these products increases the risk of fractures.
Vitamin D or calcium deficiency: a diet low in calcium throughout life causes a deficit; vitamin D deficiency may be due to too low a contribution to the diet or too low a level of sun exposure. These two deficiencies increase the risk of osteoporosis because calcium is less bound to the bones.
Lack of physical activity (physical inactivity): Physical exercise promotes the creation of strong bones.
Corticosteroids: Corticosteroids taken generally, over periods of more than three months, cause bone degradation that increases the risk of osteoporosis.
Low weight with lower BMI 19: low weight means low bone mass: the loss of a small amount of bone is therefore more serious and the risk of osteoporosis is higher.
Adapt your daily routine when you have osteoporosis
To avoid falling, it is possible to adapt your interior and your clothes (no carpets, no high objects, grab bars in the bathroom...). Eating foods rich in calcium and vitamin D is recommended (eggs, cheese, parsley, mussels, oysters...).
What are the treatments?
If the cause is defined (hyperthyroidism for example), it is important to address it.
If no cause is identified, drug treatment is based on several classes:
Bisphosphonates (their name ends with -dronate) decrease bone resorption (degradation), stabilise bone mass and increase bone mineral density. It must be continued for a minimum of three years.
Raloxifene, an anti-resorber, is more commonly used for women with osteoporosis under 70 years of age and who are at risk of breast cancer.
Teriparatide (a form similar to thyroid parathormone), called osteoreparator, is reserved for severe forms with at least 2 vertebral fractures. It can be used for patients undertaking corticosteroids, for not more than 18 months subcutaneously.
Strontium ranelate has a dual action by acting on resorption and bone formation. It can be prescribed as a second-line treatment for women under 80 years of age without a history of phlebitis or pulmonary embolism.
Treatment decisions are made based on various criteria such as fracture history, risk factors, gender and contraindications to treatment.
What is the status of medical research?
In the field of osteoporosis, biotherapies promise significant improvements, particularly with denosumab, an antibody that aims to reduce bone resorption. It is prescribed in injectable form once every 6 months. It could be used in other diseases such as ankylosing spondylitis and rheumatoid arthritis.
Sources: Article written under the supervision of Dr. Florence LEVY-WEIL, Head of Rheumatology Department at the Argenteuil Hospital Centre (France).
Published 24 Jan 2019