Osteoporosis: what it is, types and risk factors
World Health Organisation statistics indicate that more than 75 million people in Europe, the United States and Japan suffer from osteoporosis. Osteoporosis causes more than 2 million fractures annually, mainly concentrated in the hips, vertebrae and forearms. This condition is more prevalent among postmenopausal women, with estimates suggesting that around 21% of women between the ages of 50 and 84 suffer from osteoporosis. Men over the age of 50 are also at risk of developing osteoporosis. With this data in mind, we will define what osteoporosis is, who is most at risk of developing it, and what we can do to prevent it.
What is osteoporosis?
According to the WHO and the Spanish Society of Rheumatology, "osteoporosis is a skeletally systemic disease characterized by low bone mass and deterioration of the bone microarchitecture, which results in increased bone fragility and susceptibility to fractures."
Types of osteoporosis
Osteoporosis is classified as:
- Primary osteoporosis: it is the most frequent, representing 90% of cases, both in women and men. It is mainly characterized by increased bone resorption that affects the bone microarchitecture, although in some cases it can be due to abnormalities in bone formation. It is caused by factors such as gonadal deficiency in both sexes, menopause, low calcium intake, and low levels of vitamin D and hyperparathyroidism.
- Secondary osteoporosis: it represents less than 5% of cases in women and around 20% in men. It is related to underlying conditions or diseases, such as chronic kidney disease, endocrine disorders (hyperthyroidism, hypogonadism, diabetes mellitus, etc.), hyperphosphatemia, alterations in calcium levels and serum vitamin D concentration, reduced mobility, long-term steroid treatment, prolonged lack of gravitational weight-bearing (as experienced by astronauts during space flights), alcoholism, smoking, among others.
Symptoms of osteoporosis
Generally, people with osteoporosis are asymptomatic, and when a fracture occurs, the disease is already established. The symptoms that may arise include:
- Back pain, which is often caused by a vertebral fracture.
- Fractures due to fragility.
- Reduction in height.
- Postural manifestations, such as stooped posture.
Risk factors for osteoporosis
The main risk factors for developing osteoporosis include: sex (more common in women than men), age (higher prevalence in older adults), race, lifestyle (diet and sedentary behavior), hormonal levels, smoking and alcohol consumption, menopause, low body mass index, and previous bone fractures.
Osteoporosis and Menopause
According to data from the World Health Organization (WHO), osteoporosis is three times more common in women than in men. Why is that? On the one hand, women have less bone mass and, on the other hand, there are hormonal changes that occur during menopause.
The peak of bone mass occurs around the age of 30, then stabilizes for about a decade, and from the age of 50, there is a loss of bone mass of up to 0.5% per year due to aging. Estrogen levels play a key role in preserving bone mass in adulthood, so around the age of 50, when estrogen levels begin to decrease, so does bone mass.
Can osteoporosis progression be prevented during menopause?
The key to maintaining good overall bone health and preventing bone loss in people at risk of osteoporosis lies in dietary habits and regular exercise. During menopause, as already mentioned, estrogen plays a fundamental role in bone mineralization. Therefore, especially during this stage, bone mass should be preserved to prevent skeletal fragility and reduce the risk of fractures,
For this reason, during menopause, the patient should be thoroughly evaluated to determine the appropriate approach for their condition.
In many cases, it requires modifying dietary habits, activity patterns, adequate intake of essential nutrients for the skeleton, etc. It is also important during menopause to maintain a healthy weight, minimize caffeine and alcohol consumption, and avoid smoking.
Osteoporosis in men over 70
Although postmenopausal women are the main at-risk group, the Spanish Society of Rheumatology states that osteoporosis in men is underdiagnosed, and "it is estimated that one-third of hip fractures worldwide occur in men over 70 years old. Furthermore, mortality after a hip fracture (over 37% within the first year) is higher than in women."
Consequences of osteoporosis
The most significant consequence and the one with the greatest morbidity of osteoporosis is fractures, which cause pain and functional impairment. The disability caused by fractures depends on the location of the fracture. According to the Spanish Society of Rheumatology, some of the common fractures are:
- The distal forearm fracture generally recovers well from a functional point of view.
- Proximal humerus fracture in some cases requires surgery and usually recovers well.
- Hip fracture requires hospitalization and surgical intervention in virtually all cases. It also carries a risk of mortality in the first 3-6 months. Recovery is slow and often incomplete, so many patients remain institutionalized permanently after a hip fracture.
- Osteoporotic vertebral fracture (OVF) is the most frequent complication of osteoporosis and is defined as a loss of more than 20% of the anterior, posterior, or central height of a vertebra. Pain secondary to OVF is intense, appears with movement, and can cause significant functional limitation. The most immediate consequence of OVF is a decrease in height and deformation of the spine.
Calcium and vitamin D supplements
As we have read, levels of calcium and vitamin D are crucial for good bone health, being recommended by different societies and by the World Health Organization. Let's see the reasons and the suggested amounts.
- Calcium: it is the most abundant mineral in the body, with a content of 1.2 kg. 99% of calcium is found in bones and teeth. Peak bone mass is one of the key factors determining bone mass and fracture risk later in life, and calcium is a basic element for its achievement. Different studies have shown that calcium supplementation is effective in reducing bone loss in women in a late stage of postmenopause (>5 years after it), especially in those with a low habitual calcium intake (<400 mg/day).5 Intake recommendations range from 800 to 1000 mg/day.
- Vitamin D: it is produced in the skin as a result of the action of ultraviolet light. Vitamin D promotes calcium balance by improving intestinal absorption of calcium, in addition, it stimulates bone matrix formation and bone maturation. Its deficiency can increase the risk of fractures, and it has been shown that in postmenopausal women, vitamin D combined with calcium supplements reduces the rate of bone loss and also improves muscle strength and balance, reducing the risk of falls.3,5 The recommended doses range from 400-800 IU/day of vitamin D.
There are also two other minerals of interest in bone health, such as magnesium and zinc, the former being related to bone structure and the latter to bone formation and mineralization. Intake of these two minerals should cover 300 mg/day for magnesium and 10-25 mg/day for zinc.
