More than two decades ago, the famous NHANES III study found that approximately 10% of people aged 50 and over suffer from osteoporosis. In 2010, these results were supplemented with the new findings: apart from 10% suffering from osteoporosis, 43% more have osteopenia. In other words, over 50% of people older than 50 have low bone mass or osteoporosis! That makes over 50 million people only in the United States.
Osteoporosis is a progressive metabolic bone disease characterized by the loss and disrupted structure of bone tissue. As the term osteoporosis says, the bones become porous, and it makes them fragile and prone to fractures. This susceptibility to fractures is the most important feature of osteoporosis. A state in which the bone density is lowered, but not enough to make one prone to fractures, is called osteopenia. Osteopenia is far more common than osteoporosis, but though less dangerous, it should be taken as a warning sign for the upcoming osteoporosis development.
Bone tissue is complex and dynamic. From birth till death, it is constantly being resorbed and deposited again, and this is called bone remodelling. That way, tiny damages on bones are being repaired, and used up tissue is being replaced with the new, stronger one, according to the direction and intensity of force acting on the bones. Around 10% of the body’s bone tissue is destroyed and replaced each year, so in 10 years, the entire skeleton is replaced.
But to keep the skeleton complete and strong, the opposite processes of resorption and deposition must be balanced. This is the case in children and young adults, where resorption and deposition are either balanced, or the deposition is greater than the resorption. Overall, it leads to an increase in bone mass until the peak is reached in the third decade of life.
After that, the resorption process slowly becomes greater than deposition, and the bone mass starts to decrease. This decrease can be noted within the first 10 years from reaching the peak bone mass, and it is a normal and inevitable component of aging.
However, due to the lower levels of estrogens, which normally promote bone deposition and reduce resorption, the loss of bone mass is accelerated in women after menopause. The same can’t be told for men after andropause – although lower levels of male sex hormones would produce the same effect, this rarely happens, even at an advanced age. For this reason, osteoporosis is commonly a disease of postmenopausal women.
Apart from aging, osteoporosis can also develop as a result of having other medical conditions or using certain medications, that impair the process of bone remodeling.
Osteoporosis that happens due to aging is also called primary, and there are two types of it:
The type of osteoporosis that is triggered by the decrease of sex hormone levels. As mentioned, this type is practically reserved for postmenopausal women, although it can happen in both sexes. Patients with postmenopausal osteoporosis have a ‘high bone turnover’ – the bone is being quickly deposited on the outer surface of the bone, but it is even more quickly resorbed from the inside. Overall, bone mass is lost at a rate of around 2% per year, and the patients are at a special risk of vertebral fractures. Osteoporosis type I is 6 times more common than type II.
The type of osteoporosis that is solely the result of aging. Though osteoporosis in men is usually type II, it is still twice more common in women than in men. Senile osteoporosis is also known as low-turnover, and bone mass is lost at the rate of around 0.3% per year in men, and 0.5% per year in women. It usually leads to hip fractures.
Happens as a consequence or complication of other well-defined medical conditions, such as:
Caused by long-term and/or high-dose usage of certain medications. This is usually the case with glucocorticoids, but other medications such as thyroid hormone, heparin, methotrexate, loop diuretics, protein pump inhibitors, antidepressants, and anticonvulsants, can also cause this kind of secondary osteoporosis.
Risk factors for osteoporosis are numerous and knowing them is paramount for the prevention and treatment of the disease. Some of them will be listed here.
Osteoporosis is a sneaky disease that gradually develops over years, without giving any specific symptoms. Bones slowly lose their density, strength, and form, until a fracture happens as the first sign of something going on. For this reason, osteoporosis is sometimes referred to as ‘the silent bone thief.
Common fracture sites are the spine, hip, wrist, forearm, and pelvis. What is characteristic of osteoporosis is that the force that causes the fracture would be far too weak to cause a fracture in a non-osteoporotic bone. Fractures can sometimes even occur as a result of sneezing or coughing.
Hip, pelvis, and arm fractures cause acute pain and loss of function. The recovery process is slow, and hip and pelvis fractures usually also require a hospital admission, leading to great costs. Rehabilitation is often incomplete, which affects the quality of life and sometimes condemns the patients to institutionalization in a nursing home.
Vertebral fractures, on the other side, often go unnoticed. They can be followed by sudden-onset back pain that worsens when the patient is standing or walking and diminishes when the patient is lying. Disability and deformity levels depend on the number of fractured vertebrae, and these fractures lead to the loss of height.
The medical impact of osteoporotic fractures is huge. For example, excess mortality within 1 year after a hip fracture is 8 to 36%, and only 20% of the patients regain the pre-fracture function level. Vertebral and rib fractures can impair the function of abdominal organs and lungs. Other fracture sites are also associated with disability, deformity, and mortality.
Two million fractures are attributed to osteoporosis each year only in the United States. These result in over 400,000 hospital, and almost 200,000 nursing home admissions. By 2025, the annual cost of care for these patients is expected to rise to $25.3 billion.
The doctor will diagnose you with osteoporosis based on the results of physical examination, laboratory tests, bone density test, and the FRAX score.
Bone density test or dual-energy X-ray absorptiometry (DXA) is the crucial diagnostic test for osteoporosis and the only one that can diagnose it before a fracture occurs. This is a simple radiological procedure that determines the amount (density) of mineralized bone tissue in a certain part of a bone. It is usually measured on the hips or spine, although the latter is not the best choice for elderly patients as degenerative changes can mask the findings. Any other bone can be used for measurement too.
No special preparation is needed for the testing. The patient should wear comfortable, loose clothes, without any metal parts such as zippers. The whole procedure is painless and takes no more than 10-15 minutes. Any previous DXA results should be brought to the testing for comparison.
The results are reported using a T score:
| T Score | Meaning |
|---|---|
| -1 or above | Normal Bone Density |
| Between -2.5 and -1 | Osteopenia |
| -2.5 and Below | Osteoporosis |
FRAX score is a supplementing risk assessment test, which determines the 10-year risk of fractures. It is usually shown as a part of the DXA results.
National Osteoporosis Foundation (NOF) suggests that DXA should be done in every woman over 65 and every man over 70. Every person over 50 with fractures of predilection bones, and people with a significant loss of height and/or back pain that may be caused by vertebral fractures.
DXA should be done once every 1-2 years. It is recommended to always do it at the same place, with the same equipment, and by the same person. That way, the results can be compared more reliably.
Since osteoporosis develops without any symptoms for a long time, most of countries have developed screening programs to diagnose the disease early, before any fractures occur. This allows early treatment and slowing down the progression of the disease.
Osteoporosis can be treated, but cannot be cured. The treatment is directed towards those who have low bone density, and are at risk of fractures, whether or not they’ve already had one. The aim is to slow down the progression of the disease and to prevent future falls.
Perhaps more important is prevention. Prevention of osteoporosis means eliminating modifiable risk factors, slowing down the onset of the disease, or completely preventing it. Such measures should be implemented in every person, regardless of age, but especially in those who are loaded with risk factors that cannot be changed, such as gender.
Osteoporosis treatment can be divided into two sections: lifestyle changes, that every person regardless of age should try to implement, and drug treatment, which is reserved for those already suffering from osteoporosis.
A modification of diet is necessary for those who suffer from osteoporosis, or who are at risk of it. Vitamin D and calcium are critical nutrients in terms of osteoporosis development, and the intake of these two is insufficient in most people, especially the elderly.
Dairy products are the main source of calcium, and nuts, pulses, and vegetables such as cabbage and spinach can be a good source too. Although vitamin D can be produced in the skin after exposure to UVB sunrays, this production is insufficient and adequate intake of vitamin D should be taken by consumption of animal fats, fish, liver, and dairy products.
Both vitamin D and calcium can also be supplemented in people suffering from osteoporosis. However, the effects of this supplementation are moderate.
Sufficient protein intake is also beneficial for those suffering from osteoporosis, as well as an increase in vitamin K, vitamin B6, vitamin B12, vitamin E, magnesium, and zinc intake. Overall, the diet should be balanced, consisting of fruits, vegetables, and proteins with an adequate intake of vitamin D and calcium.
Excessive alcohol intake is a major risk factor for falls and fractures, and excessive caffeine intake may have similar effects. Therefore, the consumption of alcohol and caffeine should be lowered, or stopped if possible. It is recommended that the alcohol intake is no more than 2 drinks per day for women and 4 drinks per day for men. Both sexes should not drink more than 2.5 cups of coffee or 5 cups of tea per day.
Smoking has been shown to decrease bone mass density in all sites, which is why quitting this harmful habit is highly recommended.
An appropriate level of physical activity is necessary to maintain the strength and health of the bones. Even short periods of immobilization show an adverse effect on the bone mass density - for bone remodeling to be successful and purposeful, bones must be exposed to force.
Physical activity in those who are at risk, or suffering from osteoporosis, should be a combination of low and high-impact aerobic activities, such as walking or jogging, and muscle-strengthening activities, such as weight lifting or cycling. Balance-improving exercises should also find their place in this exercise plan.
However, given that elderly people are in question, doctors should take special attention and perform thorough physical examinations before prescribing exercise. Even modest physical activity is useful in terms of the prevention of falls and fractures in the elderly.
Sunlight exposure is necessary for vitamin D to be produced in the skin. This production is getting lower with age, and it is further impaired by the lack of sunlight exposure that is particularly typical for the elderly. To provide conditions for normal production of vitamin D in the skin, it is recommended to spend 30 minutes per day for 5 days a week in the sunlight.
Fall prevention is the priority for people suffering from osteoporosis. Apart from the already mentioned physical exercise, vitamin D and calcium supplementation, smoking cessation, and moderation of alcohol consumption, other measures such as the usage of different orthoses can also be considered.
Environmental obstacles, such as inadequate footwear, low lighting, carpets, and cables, should be assessed too.
In those already suffering from osteoporosis, apart from suggesting the listed lifestyle changes, the doctor will also prescribe certain medications. The aim of this drug treatment is mainly to decrease the risk of fracture.
Bisphosphonates, such as risedronate, ibandronate, and alendronate, are the most commonly used class of drugs. These drugs decrease the rate of bone resorption, lower the bone turnover, and increase bone density, hence lowering the risk of fractures. The treatment with these drugs is continued over at least 5 years and can be prolonged up to 10 years or even more, depending on the risk reassessment results.
Estrogen replacement therapy was used for similar purposes in postmenopausal women, however, it is no longer in use due to an increased risk of breast cancer, thromboembolic events, and stroke. Estrogen therapy is nowadays only used temporarily in specific cases, or it is replaced by therapy with more advanced class of drugs called the selective estrogen receptor modulators.
Depending on the severity of osteoporosis and other circumstances, several other therapeutic approaches can be used too.
