Osteoporosis is a condition characterized by a decrease in the density of bone, decreasing its strength and resulting in fragile bones. Osteoporosis literally leads to abnormally porous bone that is compressible, like a sponge.
This disorder of the skeleton weakens the bone and results in frequent fractures (breaks) in the bones. Osteopenia is a condition of bone that is slightly less dense than normal bone but not to the degree of bone in osteoporosis.
Normal bone is composed of protein, collagen, and calcium, all of which give bone its strength. Bones that are affected by osteoporosis can break (fracture) with relatively minor injury that normally would not cause a bone to fracture.
The fracture can be either in the form of cracking (as in a hip fracture) or collapsing (as in a compression fracture of the vertebrae of the spine). The spine, hips, ribs, and wrists are common areas of bone fractures from osteoporosis although osteoporosis-related fractures can occur in almost any skeletal bone.
Osteoporosis can be present without any symptoms for decades because osteoporosis doesn't cause symptoms until bone fractures. Moreover, some osteoporotic fractures may escape detection for years when they do not cause symptoms.
Therefore, patients may not be aware of their osteoporosis until they suffer a painful fracture. The symptom associated with osteoporotic fractures usually is pain; the location of the pain depends on the location of the fracture. The symptoms of osteoporosis in men are similar to the symptoms of osteoporosis in women.
Fractures of the spine (vertebra) can cause severe "band-like" pain that radiates from the back to the sides of the body. Over the years, repeated spinal fractures can lead to chronic lower back pain as well as loss of height and/or curving of the spine due to collapse of the vertebrae. The collapse gives individuals a hunched-back appearance of the upper back, often called a "dowager hump" because it commonly is seen in elderly women.
A fracture that occurs during the course of normal activity is called a minimal trauma, or stress fracture. For example, some patients with osteoporosis develop stress fractures of the feet while walking or stepping off a curb.
Hip fractures typically occur as a result of a fall. With osteoporosis, hip fractures can occur as a result of trivial accidents. Hip fractures also may heal slowly or poorly after surgical repair because of poor healing of the bone.
Osteoporosis occurs when there is an imbalance between new bone formation and old bone resorption. The body may fail to form enough new bone, or too much old bone may be reabsorbed, or both. Two essential minerals for normal bone formation are calcium and phosphate. Throughout youth, the body uses these minerals to produce bones.
Calcium is essential for proper functioning of the heart, brain, and other organs. To keep those critical organs functioning, the body reabsorbs calcium that is stored in the bones to maintain blood calcium levels. If calcium intake is not sufficient or if the body does not absorb enough calcium from the diet, bone production and bone tissue may suffer. Thus, the bones may become weaker, resulting in brittle and fragile bones that can break easily.
Usually, the loss of bone occurs over an extended period of years. Often, a person will sustain a fracture before becoming aware that the disease is present. By then, the disease may be in its advanced stages and damage may be serious.
The leading cause of osteoporosis is a lack of certain hormones, particularly estrogen in women and androgen in men. Women, especially those older than 60 years of age, are frequently diagnosed with the disease. Menopause is accompanied by lower estrogen levels and increases a woman's risk for osteoporosis.
Other factors that may contribute to bone loss in this age group include inadequate intake of calcium and vitamin D, lack of weight-bearing exercise, and other age-related changes in endocrine functions (in addition to lack of estrogen).
Other conditions that may lead to osteoporosis include overuse of corticosteroids (Cushing syndrome), thyroid problems, lack of muscle use, bone cancer, certaingenetic disorders, use of certain medications, and problems such as low calcium in the diet.
The following are risk factors for osteoporosis:
- Women are at a greater risk than men, especially women who are thin or have a small frame, as are those of advanced age.
- Women who are white or Asian, especially those with a family member with osteoporosis, have a greater risk of developing osteoporosis than other women.
- Women who are postmenopausal, including those who have had early or surgically induced menopause, or abnormal or absence of menstrualperiods are at greater risk.
- Cigarette smoking, eating disorders such as anorexia nervosa or bulimia, low amounts of calcium in the diet, heavy alcohol consumption, inactive lifestyle, and use of certain medications, such as corticosteroids and anticonvulsants, are also risk factors.
- Rheumatoid arthritis itself is a risk factor for osteoporosis.
- Having a parent that has/had osteoporosis is a risk factor for the offspring.
The goal of treatment of osteoporosis is the prevention of bone fractures by reducing bone loss or, preferably, by increasing bone density and strength. Although early detection and timely treatment of osteoporosis can substantially decrease the risk of future fractures, none of the available treatments for osteoporosis are complete cures.
In other words, it is difficult to completely rebuild bone that has been weakened by osteoporosis. Therefore, prevention of osteoporosis is as important as treatment.
The following are osteoporosis treatment and prevention measures:
- Lifestyle changes, including quitting cigarette smoking, curtailing excessive alcohol intake, exercising regularly, and consuming a balanced diet with adequate calcium and vitamin D.
- Medications that stop bone loss and increase bone strength, such as alendronate (Fosamax), risedronate (Actonel), raloxifene (Evista), ibandronate (Boniva), calcitonin (Calcimar), zoledronate (Reclast), and denosumab (Prolia).
- Medications that increase bone formation such as teriparatide (Forteo).
Exercise, quitting cigarettes, and curtailing alcohol
Exercise has a wide variety of beneficial health effects. However, exercise does not bring about substantial increases in bone density. The benefit of exercise for osteoporosis has mostly to do with decreasing the risk of falls, probably because balance is improved and/or muscle strength is increased. Research has not yet determined what type of exercise is best for osteoporosis or for how long it should be continued. Until research has answered these questions, most doctors recommend weight-bearing exercise, such as walking, preferably daily.
A word of caution about exercise:
It is important to avoid exercises that can injure already weakened bones. In patients over 40 and those with heart disease, obesity, diabetes mellitus, and high blood pressure, exercise should be prescribed and monitored by physicians.
Extreme levels of exercise (such as marathon running) may not be healthy for the bones. Marathon running in young women that leads to weight loss and loss of menstrual periods can actually promote osteoporosis.
Smoking one pack of cigarettes per day throughout adult life can itself lead to loss of 5%-10% of bone mass. Smoking cigarettes decreases estrogen levels and can lead to bone loss in women before menopause. Smoking cigarettes also can lead to earlier menopause. In postmenopausal women, smoking is linked with increased risk of osteoporosis.
Data on the effect of regular consumption of alcohol and caffeine on osteoporosis is not as clear as with exercise and cigarettes. In fact, research regarding alcohol and caffeine as risk factors for osteoporosis shows widely varying results and is controversial. Certainly, their effects are not as great as other factors. Nevertheless, moderation of both alcohol and caffeine is prudent.