Osteoporosis: what it is, types and risk factors
Published: 23 February, 2023 - Updated: 26 October, 2023 | 10'
The statistics from the World Health Organization show numbers of over 75 million people with osteoporosis in Europe, the United States, and Japan.
Osteoporosis causes over 2 million fractures annually, mainly in the hips, vertebrae, and forearms. Its prevalence is higher in postmenopausal women, where it is estimated that approximately 21% of women between 50 and 84 years old have osteoporosis. Men over 50 years old also have a high probability of developing osteoporosis.
With these data in mind, let’s find out what osteoporosis is, which people are at higher risk of developing osteoporosis, and what we can do to prevent it, with the guidance of Doctor Álvaro Sanjuán, a specialist in sports medicine, rehabilitation, and bone densitometry.
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?
As explained by Doctor Álvaro Sanjuán, “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”, says the doctor.
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.
Common bone fractures
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.
How is osteoporosis diagnosed?
The diagnosis of osteoporosis should first be sought through the patient’s medical history and physical examination. Factors to consider include: risk factors, height loss of more than 3.81 cm (with annual measurements), excessive kyphosis of the thoracic spine, widow’s hump, dental caries, tooth loss, receding gums, back pain, among others.
After this initial evaluation, a blood chemistry analysis can be performed to provide information about kidney and liver function, primary hyperparathyroidism, and possible malnutrition (calcium levels, magnesium, vitamin D, etc.). Likewise, it can detect metabolic bone markers that are useful for determining the level of bone resorption.
Radiographic images are another key factor in identifying osteoporosis. However, a plain X-ray can only suggest a decrease in bone mineral density, so it is recommended to confirm the diagnosis through bone density measurement (BMD).
BMD is the amount of bone mass per unit area, and its measurement provides information about the probability of fracture and serves as a basis for assessing patients’ progress. There are different methods for measuring BMD, including densitometry, tomography, and ultrasound.
Densitometry is the most widely used method and measures BMD using a T-score. The World Health Organization defines osteoporosis as a BMD or bone mineral content more than 2.5 standard deviations (SD) below the average peak BMD of young, healthy adults of the same sex and ethnicity.
Bone Densitometry: What is it and what does it show?
As explained by Dr. Álvaro Sanjuán, a bone densitometry specialist, “Bone densitometry measures the calcium content of the bone at a given time”.
Who should undergo a bone densitometry test?
This test, the doctor “is usually carried out, generally, in women from menopause onwards, in men over 50 years old with osteoarticular pain, and in specific cases, in patients with serious alterations in vitamin D3 and parathyroid hormone in the blood, in cases of calcium and phosphorus metabolism disorders, in cases of polytrauma to rule out post-traumatic osteoporosis, in patients in a state of rest or prolonged immobilization, or in patients undergoing long-term corticosteroid treatments”.
From what age is it recommended to perform this test?
In general, says Dr. Sanjuán, “it is usually recommended to perform it from 45-50 years old”, being, as mentioned, highly recommended in the case of women from menopause onwards and men over 50 years old with osteoarticular pain.
How often should a bone densitometry test be repeated?
“BMD is a measurement of the calcium content of the bone at a specific moment, so it is important to observe its evolution”, says Dr. Sanjuán. Therefore, “depending on the result of the first test, it would be repeated every one, two or three years (at most), especially when medical treatment is administered”.
Management of osteoporosis
As the Spanish Society of Rheumatology assures: “both in the prevention and treatment of osteoporosis, it is important to reduce risk factors, prevent falls, and recommend optimal nutrition”.
The recommendations in this regard are as follows:
- Quit smoking and avoid excessive alcohol consumption.
- Regularly engage in physical exercise, preferably load-bearing.
- Optimize body mass index.
- Have adequate exposure to sunlight.
- In fall prevention, it is important to adapt the patient’s environment, identify medications that may increase their risk, and correct visual deficits.
- Recommend nutrition that includes the 3 basic nutrients for bone health: calcium, vitamin D, and proteins.
The dietary recommendations focus on foods that can help preserve bone mass. Some examples would be:
- Increase consumption of foods rich in calcium such as milk, skimmed dairy products, nuts and seeds, whole grains, green vegetables, and sardines.
- Combine the above with foods rich in vitamin D (fatty fish, eggs, and brown rice), and foods rich in vitamin C (citrus fruits, bell peppers, Brussels sprouts, watercress).
- Increase consumption of vegetables, fruits, and vegetables.
- Consume legumes, including
- Preferably use seed or olive oils (sources of unsaturated fat rich in vitamin E).
- Moderate consumption of animal proteins (meat, fish, eggs).
- Preferably consume fish, especially oily fish, due to its content of essential fatty acids (Omega-3).
- Limit consumption of animal foods high in saturated fats.
- Reduce consumption of coffee, alcohol, and carbonated and sugary drinks.
- Moderate salt consumption.
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.
It is important for the specialist to adequately instruct the patient with osteoporosis about the risks of falls and fractures. As Dr. Sanjuán explains, “home safety must be ensured, medications that may affect the patient’s balance and coordination must be identified, and individual programs must be developed to help improve their physical stability and prevent fractures”.
Some tips for falls prevention include: avoiding walking on uneven or wet terrain without appropriate footwear, avoiding walking in the dark at home, shoes should be suitable and fully support the foot, postural hygiene exercises, monitoring climbing and descending stairs, adapting the bathroom to prevent slips, among others.
In these programs, core strengthening exercises can increase stability.
Does exercise help with osteoporosis?
“Definitely, exercise is essential for strengthening muscles and reducing bone loss, as well as preventing falls in people with osteoporosis”, says the doctor.
Among the recommended exercises for people with osteoporosis, load-bearing exercises are generally recommended, and some examples would be:
- Balance exercises such as taichi help reduce the risk of falls.
- Combine balance exercises with strength training, which promotes strengthening of the muscles and bones of the arms and upper spine.
- Weight-bearing exercises, such as walking or climbing stairs, primarily benefit the bones of the legs, hips, and lower spine.
- For people with kyphosis (exaggerated forward curvature of the upper back), studies have shown the effectiveness of weight-bearing exercises; as well as muscle strength and balance training.
Among the exercises that are not recommended for patients with osteoporosis are high-impact exercises such as running or jumping, “as they can cause fractures in weakened bones”, explains Dr. Álvaro Sanjuán.
“It is important to note that these are general examples, and the best recommendation for the type and duration of exercise can be provided by your healthcare provider based on your medical history”, he adds.
How does osteoporosis affect quality of life?
As we have seen, the most common clinical complications of osteoporosis are vertebral fractures and deformities, as well as hip and wrist fractures. In more extreme cases, there is a risk of mortality from these complications.
Hip fractures greatly diminish quality of life due to the resulting dysfunctionality.
Pain is a cardinal symptom that has a considerable negative impact on daily activities, which also affects emotional and social well-being.
In a study that evaluated the quality of life in more than 700 patients with osteoporosis, osteopenia, and no bone involvement, it was shown that more than 40% of osteoporotic patients claim to have some difficulty walking and another group said they have difficulty performing daily activities (23.94%). In addition, more than 45% of patients with osteoporosis report experiencing pain, and 14.09% report being very anxious/depressed.
Based on all the above, an early diagnosis of osteoporosis along with appropriate intervention, whether a fracture has occurred or not, is key to reducing the impact of this health condition and improving the quality of life of the individual.
1) Alperi López, M. (ed.). Manual SER de enfermedades reumáticas. 6ta. Edición. Sociedad Española de Reumatología (SER) 2014. ISBN edición electrónica: 978-84-9022-905-7.
2) Castiglioni, S. et al. Magnesium and Osteoporosis: Current State of Knowledge and Future Research Directions. Nutrients. 2013 Aug; 5(8): 3022–3033.
3) Dobbs, M. B. et al. Osteoporosis. Iowa Orthop J. 1999; 19: 43–52.
4) Lafita, J. Fisiología y fisiopatología ósea. Anales Sis San Navarra vol.26 supl.3 Pamplona 2003.
5) Lanham-New, S. A. Importance of calcium, vitamin D and vitamin K for osteoporosis prevention and treatment. Proceedings of the Nutrition Society (2008), 67, 163–176.
6) Osteoporosis. Clínica Mayo.
7) Osteoporosis. Manual MSD.
8) Recomendaciones SER sobre Osteoporosis. Sociedad Española de Reumatología.
9) WHO Technical Report Series 921. Prevention and Management of Osteoporosis: Report of a WHO Scientific Group. WHO Library Cataloguing-in-Publication Data, 2003. ISBN 92 4 120921 6.
10) Yamaguchi, M. Role of nutritional zinc in the prevention of osteoporosis. Mol Cell Biochem (2010) 338:241–254.
Content developed by the specialists of the Scientific Information area of MARNYS with the collaboration of Dr. Álvaro Sanjuán. This article is for informational purposes only and does not replace consultation with a specialist.
About the specialist
Dr. Álvaro Sanjuán is a physician specialized in sports medicine, rehabilitation, and Bone Densitometry.