What is osteoporosis?
Osteoporosis literally means ‘ porous bone ‘. It is a very common disease that affects the bone, and is characterized by a decrease in bone mass (of the amount of bone per unit of volume), and an alteration of the architecture of the bones. This results in greater fragility and thinning of the same (known as Osteopenia), and increased risk of fractures.
The main fractures mainly affect vertebrae, wrists and neck of the femur or hip. Osteoporosis is more common in women and, specifically, after menopause. This is mainly due to two reasons: on the one hand the peak of maximum bone density reached in the fourth decade of life is less than that of men, and the hormonal influence of this pathology suffers the maximum decline in menopause.
Who does osteoporosis affect?
Osteoporosis is the most common bone disease. It produces every year more than 1,300,000 of fractures of vertebrae, hip and wrist in the world. And these fractures increase the risk of other successive ones, at the rate of four times more risk after a first vertebral fracture and twice as much for the hip fracture.
In the United States, approximately 55% of people over the age of 50 are at high risk for osteoporosis. In Spain it affects about three million people. This implies a prevalence of about 26%.
The risk of fractures increases exponentially with age, which is a major health problem in the elderly. Therefore, fractures and age are their main risk factors. Taking care of our bones throughout life is vital in order to prevent this pathology. (1)
Causes of osteoporosis
Throughout life, as the bone is destroyed, new bone is forming, maintaining a balance. This process is called bone remodeling. As of the third Decade, the remodeling process changes, and the formation of new bone becomes slower, so it naturally produces a decrease in the mass of the bone. When this loss of bone mass becomes more severe, osteoporosis occurs.
There are several causes of osteoporosis, or rather, several factors that favor its emergence:
» Ageing: The advanced age, by itself, produces a decrease in the amount of bone, so that anyone can suffer it. The risk is greater from 50 years.
» Weight: A BMI less than 19 increases the risk of osteoporosis, since it has a direct relationship with bone density.
» Genetic factors: There are genes related to the development of bone mass, so the incidence of the disease is greater in those people whose direct relatives have previous history of fractures (parents or grandparents).
» Poor calcium diet: Calcium is a fundamental food in bone formation. It is mostly found in milk and dairy derivatives such as cheeses, yogurts, etc., and also in other foods such as blue fish and nuts.
» Female sex: Women have a four times greater risk than men to develop osteoporosis, especially after menopause. This is due to the reduction in the number of estrogens (female hormones involved in the formation of bone mass) at this stage, which favors a decrease in bone remodeling.
There is more likelihood of osteoporosis if menopause occurs before 40 years (early menopause), due for example to the surgical extirpation of both ovaries, or when menstruation is absent (called amenorrhea) in athletes, or in cases of anorexia nervosa due to significant loss of weight.
In addition, women have a higher life expectancy than men and, in general, their amount of bone mass is lower (especially in excessively thin women).
» Breed: More frequent in Caucasians and Asians.
» Some pathologies: there are diseases that can trigger osteoporosis, such as hyperthyroidism or Cushing’s syndrome.
» Prolonged immobilization: either by illness or by a sedentary lifestyle. Exercise is one of the stimuli for bone formation.
» Some medications: for example, prolonged use of steroids, corticosteroids, aeds, or thyroid drugs.
» The excess of tobacco, alcohol or coffee.
Symptoms of Osteoporosis
Osteoporosis tends to take an asymptomatic course until a fracture occurs. They are called ‘ brittle fractures ‘. It is a common mistake to attribute pain from limbs, lumbar or some joint to osteoporosis. Osteoporosis doesn’t hurt. (2)
The most frequent are the fractures of the vertebrae, and a large majority are asymptomatic and are accidentally diagnosed by an X-ray, or another test of image that is requested for another reason. When symptoms are present, they tend to have acute or chronic pain (duration of more than six months).
Spinal deformities (progressive kyphosis, or, as is popularly known, hump or hump) (drawing of an elderly person with a hump) and a decrease in size. They are located mostly in the lower half of the dorsal column and in the upper half of the lumbar spine.
Hip fractures (hip drawing) are also very prevalent and affect 15% of women and 5% of men over 80 years. They are usually the result of a fall, and are in acute pain and inability to mobilize the affected limb. Often the treatment of this type of fractures is surgical, so it is a frequent cause of hospital admission in elderly people.
There are, therefore, the following forms of onset or symptoms that may indicate the presence of osteoporosis:
» Detection in asymptomatic people with no history of previous fractures presenting multiple risk factors (loss of menstruation before 40 years, or after surgery for the removal of the ovaries, family history of osteoporosis or fractures, inadequate diet poor in calcium, sedentary lifestyle, alcohol or tobacco abuse, or prolonged treatment with certain drugs). (3)
» To present fractures of recurrence of long bones (humerus, femur or radio at the level of the wrist) spontaneously, or to minimal blows or falls.
» have vertebral fractures by a small movement (coughing, sneezing, or crouching), or even unrelated to any triggers.
» As a result of repeated vertebral fractures, it is possible to produce, especially in more advanced ages, a decrease in the size or appearance of the hump (by lowering the height of the bodies of the vertebrae).
Treatment of osteoporosis
The objective of the treatment is to avoid the established osteoporosis, ie the osteoporotic fracture and, if already exists, to avoid the production of a new one.
The preventive measures of osteoporosis that can be adopted in childhood, adolescence, youth and adulthood are aimed at reaching the maximum of bone mass (this occurs normally before 30 years, since from that age the bone remodeling is slower and promotes the decrease of bone density).
In postmenopausal women there are pharmacological and non-pharmacological measures that improve the quality of bone and slow as far as possible the loss of bone mass.
In elderly people, measures to prevent the risk of falling are playing a key role.
Non-pharmacological or preventive measures of osteoporosis
» Adequate calcium-rich diet: Calcium is lost daily through urine and sweat. If the necessities are greater than the contribution of the same, it will produce a decrease of the reserve, constituted by the bone fundamentally. Calcium is mainly found in milk and dairy derivatives such as cheese and yogurt.
Children should take at least 800 milligrams of calcium per day, adults 1,000 milligrams of calcium per day, and pregnant women 1,200 milligrams of calcium. One litre of milk contains approximately one gram of calcium element (one yogurt approximately 125 milligrams of calcium).
» Contribution of Vitamin D: promotes the absorption of calcium and its incorporation into the bone. For most adults sun exposure and a balanced diet are sufficient to maintain adequate levels, but in elderly people who often come out little to the street is often insufficient. Vitamin D needs range from 400 to 800 IU per day. Milk constitutes the largest source of vitamin D provided by the diet, a litre of milk contains approximately 400 IU of vitamin D.
» Avoid the consumption of tobacco and alcohol: it is recommended to abandon alcohol and smoking habit, as it accelerates the loss of bone mass by lowering the capacity of calcium absorption.
» Do not exceed caffeine: this substance has a diuretic effect that makes calcium excretion through urine more than normal. Try to moderate the consumption of coffee and other beverages that contain it.
» Daily physical exercise: daily exercise practice, such as walking 20 minutes every day, increases bone mass and decreases the risk of fractures. Also, to improve the balance and avoid cáidas you can practice sports like Taichi or yoga.
Pharmacological measures against osteoporosis
The use of drugs is indicated in those osteoporosis patients at higher risk of presenting a fracture (those with several risk factors and lower bone density). (4)
» Calcium and Vitamin D: Its use is recommended in elderly people with low intake of these elements, and in those who take drugs in a prolonged way, such as corticosteroids, which favor osteoporosis. The most commonly used calcium salts are citrate and calcium carbonate. In the market there are combined calcium and vitamin D preparations that facilitate their administration.
» Bisphosphonates (Alendrónico acid, risedrónico acid, etidrónico acid): Their mechanism of action is not well known, but they produce a decrease in bone resorption or bone destruction. Decrease the incidence of vertebral and hip fractures in women after menopause, and vertebral fractures in men. They are the treatment of choice in osteoporosis by drugs. They are administered by mouth frequently weekly or monthly.
» Raloxifen: It acts on the receptors of the estrogens (female hormone which acts in the formation of the bone). It decreases the frequency of radiological and clinical vertebral fractures in women after menopause with osteoporosis, with and without previous fracture, and significantly decreases the incidence of breast cancer in this type of patient.
» Hormonal replacement therapy (estrogens/progestogens): It is not the first choice treatment against osteoporosis. It is indicated in some women after menopause, when they do not tolerate other drugs and also have important symptoms in relation to the loss of menstruation. It may increase the risk of breast cancer and the onset of thrombus at the venous system level.
» Calcitonin: Decreases the appearance of new fractures. Their efficacy is somewhat lower. It is administered intranasally.
» Teripratida: It is a fragment of parathyroid hormone that helps the formation of bone. It’s been used for a short time. It is only indicated in certain cases (usually after a fracture), and not on a continuous way. It is administered by subcutaneous injections.
» Denosumab: It is a antiresorptive monoclonal antibody with a very important role at present to avoid osteoporotic vertebral and hip fracture. An intramuscular injection is administered every six months