Osteoporosis

When people age – particularly women – there often comes a loss of height and weight, and the development of stooped posture. A bone-thinning disease called osteoporosis (os-tee-oh-pour-osis) often causes these body changes. Osteoporosis causes destruction of bone tissue which leads to loss of bone mass. As a result, bones become brittle and the risk of fracture of the spine, hip, and wrist increases. Spinal fractures are the most common type of fractures due to osteoporosis. Forty percent of all women will have at least one spinal fracture by the time they are 80 years old. These vertebral fractures can permanently alter the shape and strength of the spine.

Most women are likely to feel some effects of osteoporosis in their lifetime, but the good news is that much can be done to reduce and even prevent loss of bone mass and fractures. New treatments for osteoporosis are being discovered each year. You can also actively work to decrease your chances of suffering the effects of osteoporosis. The key is prevention and intervention.

What Causes Osteoporosis

Loss of bone mass begins at around age 30. Although men can be affected by osteoporosis, older women are usually affected – particularly those who are past menopause. Bone loss becomes worse in women after menopause because of the body’s lack of estrogen. When bones lose mass they tend to weaken and become fragile. This increases the risk of fracture under stress or because of a fall, particularly in your spine and hip.

Falls in elderly women are often actually the result, rather than the cause, of hip fractures. In other words, a fragile hip bone may simply fracture, causing the person to fall. In severe cases of osteoporosis, the bones can fracture with any kind of slight movement, leaving some people bedridden.

Doctors have identified two types of osteoporosis, primary and secondary. Primary osteoporosis is further divided into “primary type I” and “primary type II” osteoporosis.

Primary (Type I) Osteoporosis
Most people think of this type when talking about osteoporosis. It is the form that mainly affects women after menopause. Primary type I osteoporosis is six times more common in women than men. It occurs in women 15 to 20 years after menopause. The loss of bone is linked to an estrogen deficiency in women and a testosterone deficiency in men. Amounts of these hormones tend to become low with age.

Primary type I osteoporosis is sometimes called high-turnover osteoporosis because it causes a rapid loss of the spongy inner part of the bones (called trabecular [tra-beck-you-lar] bone). Normally there is a large amount of trabecular bone in the vertebral bodies of the spine and in the end of the long bones, like the wrist. People who lose trabecular bone have a higher risk of spine and wrist fractures.

Primary (Type II) Osteoporosis
Compared to Type I, Type II osteoporosis is only two times more common in women than men. It typically occurs when people reach their 70s or 80s. It is also thought to be the result of too little calcium in the diet, low Vitamin D levels because of age, or increased activity of the parathyroid (para-thigh-roid) glands.

Primary type II osteoporosis causes a loss of both hard outer bone and spongy inner bone. Because the rate of bone turnover is much lower, primary type II osteoporosis is also called low-turnover osteoporosis. Hip fractures are the most common result of this type of osteoporosis.

Secondary Osteoporosis
In healthy people, bone is constantly regenerating. New bone is formed while old bone is resorbed by the body. This process is called remodeling. The amount of bone mass you have depends on the balance between bone formation and bone resorption. This is your bone turnover rate. If bone production is less than the amount of bone being resorbed, the risk of developing osteoporosis increases. In secondary osteoporosis, the rate of bone remodeling increases, leading to a loss of bone mass. Secondary osteoporosis can also occur from an imbalance in hormones due to the following diseases:

• Hyperparathyroidism (hy-per-para-thigh-roid-ism) – increased activity of the parathyroid glands
• Hyperthyroidism (hy-per-thigh-roid-ism) – increased activity of the thyroid glands
• Diabetes (dye-a-beet-ees) – high blood sugar due to the body’s inability to produce or use insulin correctly
• Hypercortisolism (Hy-per-cort-i-sole-ism) – high cortisol levels due to illness or long-term use of steroid medication

Secondary osteoporosis can also occur from disorders where the bone marrow cavity expands at the expense of the trabecular or spongy bone, which causes bones to lose some of their strength.

Other Causes of Secondary Osteoporosis include:

• Thalassemia (thal-a-seem-ia) – a genetic form of anemia which causes there to be too few red blood cells
• Multiple myeloma (my-a-lome-a) – a type of cancer where there are multiple tumors within the bone and bone marrow
• Leukemia (loo-key-me-a) – a serious disease in which white blood cells grow out of control
• Metastatic (met-a-stat-ic) bone disease – a condition that occurs when cancer cells spread from one part of the body through the blood stream and into the bones

Symptoms of Osteoporosis

The most common symptoms of osteoporosis are fractures – particularly vertebral compression fractures and hip fractures. Compression fractures in the spine are caused by weakened vertebrae and can lead to pain in the mid back. These fractures often stabilize by themselves and the pain eventually goes away. But the pain may persist if the crushed bone continues to move around and break.

In severe cases of osteoporosis, actions as simple as bending forward can be enough to cause a “crush fracture” in a vertebra. This type of vertebral fracture causes loss of body height and a humped back, especially in elderly women. This disorder (called kyphosis [kye-fo-sis]) is an exaggeration in the curve of the mid back. It causes the shoulders to slump forward and the top of the back to look enlarged and humped.

Consult your doctor if you have symptoms of osteoporosis. Older women should discuss their risks with their doctor, even if they are not currently showing any signs of osteoporosis. All women should be aware of the many preventive steps that can lower their risk of developing osteoporosis.

Who is at Risk for Osteoporosis

Osteoporosis does not affect everyone. There are risk factors that may predict your chances of developing it. Some risk factors are genetic, meaning you inherited them from your biological parents. Some risks are due to medical conditions that you may not be able to avoid, such as use of particular medications. Risk factors that are considered “lifestyle-related” are the ones that you can change.

Biological and Medical Risk Factors

• Biological Sex – women have a greater chance of developing osteoporosis than men
• Race – Caucasians and Asians are at greater risk of having osteoporosis
• Age – since bone loss begins at around age 30, the risk of osteoporosis increases with age
• Family History – if others in your family have experienced hip or spine fractures or become hunched over as they age, you are at greater risk of experiencing the same symptoms
• Body Frame – a thin body frame and low body weight relative to your height will increase the risk of osteoporosis
• Post-menopause – women who are past menopause have lower estrogen levels, which increases their chance of losing bone mass
• Low Estrogen – women who have had low estrogen rates over their lifetime are at higher risk for osteoporosis. Low estrogen may be because of late onset of puberty/getting their period, early menopause (before 40), or an absence or suppression of menstruation
• Medication Use – some medications increase the risk of osteoporosis because they contribute to loss of bone mass when used long-term. These drugs include steroids, inhaled steroids, anti-epileptic drugs, immunosuppressants, anticoagulants, and thyroid hormone suppressive therapy
• Nutritional Conditions – conditions such as anorexia nervosa (an-or-ex-iya ner-vo-sa), chronic liver disease, malabsorption syndromes, or malnutrition can increase the risk of osteoporosis
• Endocrine Disease or Metabolic Causes – these include thalassemia, diabetes, and hemochromatosis (heem-oh-krome-a-toe-sis)
• Other Medical Disorders – conditions such as Down’s syndrome, mastocytosis (mast-oh-sigh-toe-sis), myeloma (my-a-low-ma) and some cancers, renal tubular acidosis, rheumatologic (room-a-toe-lodge-ic) disorders, and lack of movement add to the risks for osteoporosis

Lifestyle Risk Factors

• Low Calcium Intake – less than 300 mg per day of calcium (which is equal to one glass of milk) is considered low
• Low (or no) Vitamin D in Your Diet – vitamin D comes from sunlight and foods such as egg yolks, fortified milk and cereals, and some types of fish
• High Caffeine Intake – more than two or three cups of caffeinated coffee each day is considered high if you have a low calcium intake
• Tobacco Use – this includes current use as well as past use of tobacco
• Alcohol Use – more than 7 oz. of alcohol per week can slightly increase the risk of hip fractures
• Low Activity – your activity level is considered low if you do not walk or exercise regularly

How You Can Prevent Osteoporosis

Whether you are at risk or not, below are some things you can do to help keep your bones healthy and prevent osteoporosis.

Calcium

Increasing your calcium intake is the easiest thing you can do to help prevent osteoporosis. You can increase your calcium intake by eating foods that are high in calcium or by taking a calcium supplement. It is best for people to begin adequate calcium intake at an early age, as bone mass begins to decrease around the age of 30. After age 30, calcium helps decrease bone loss, strengthen bones, and decrease the risk of fractures.

The recommended daily intake of calcium for women 25 to 50 years old and women over 50 who take hormone replacements is 1,000 mg per day. Women over 50 who do not take hormone replacements should take 1,500 mg of calcium per day. Men 25 to 65 years old should take 1,500 mg of calcium per day. Men and women over age 65 should take 1,500 mg of calcium per day.

If you take calcium supplements, make sure they contain Vitamin D, as this helps with absorption. Also, look for calcium citrate because it is absorbed better than calcium carbonate. If you take the carbonate form, make sure you take it with food.

Vitamin D
To help prevent bone loss and fracture, adults should take at least 800 mg per day of vitamin D. Many calcium supplements contain vitamin D. You can also get vitamin D through foods such as egg yolks, fish, and fortified milk and cereals. Halibut, mackerel, sardines, shrimp, pink salmon, and cod liver oil are good sources of vitamin D.

Exercise
Exercising five days a week for at least 30 minutes helps reduce the risk of bone loss. The best exercises for maintaining bone mass are weight-bearing exercises like walking, low-impact aerobics, and safe forms of dancing. Always check with your doctor before starting an exercise program.

Medications
Currently there are four medications that are approved by the US Food and Drug Administration (FDA) to help prevent bone loss and osteoporosis.

Hormone Replacement Therapy (HRT)
Hormone (estrogen) replacement therapy (HRT) is used to both prevent and treat osteoporosis. HRT can reduce bone loss, increase bone density in the spine and hips, and reduce the risk of hip and spinal fractures in postmenopausal women.

HRT is usually given as a pill or skin patch. It is effective even when started after age 70. Estrogen taken alone can increase the risk of developing endometrial (en-doh-me-tree-al) cancer (cancer of the uterine lining). For this reason, a second hormone called progestin (pro-jest-in) is usually prescribed in combination with estrogen for women still having their uterus.

Side effects of HRT can include nausea, bloating, breast tenderness, and high blood pressure. Some studies indicate a link between estrogen use and breast cancer, while other studies do not. Make sure to discuss the pros and cons of hormone replacement therapy with your doctor.

Bisphosphonates
Bisphosphonates (bis-foss-foe-nates) inhibit breakdown of bone and slow down bone resorption. They have been shown to increase bone density and decrease the risk of hip and spinal fractures. Alendronate (al-en-dro-nate) is the bisphosphonate that has been approved by the FDA for preventing and treating osteoporosis in postmenopausal women. The strongest side effect of alendronate is gastrointestinal problems. To avoid these problems, alendronate should be taken with a full glass of water and on an empty stomach, and you should remain in an upright position for at least thirty minutes after taking alendronate.

Calcitonin
Calcitonin (kal-si-toe-nin) is recommended for women who cannot or choose not to take estrogen or hormone replacement therapy. For women who are at least five years past menopause, calcitonin can increase spinal bone density and slow bone loss. Calcitonin is a protein, so it cannot be taken by mouth because it would digest before it is able to work. Calcitonin is available as an injection or nasal spray.

Selective Estrogen Receptor Modulators (SERMs)
SERMs are medications that have effects similar to estrogen in some parts of the body, such as the spine and hip. SERMs seem to prevent bone loss of the spine, hip, and total body. Raloxifene (rah-lox-i-feen) is the SERM drug currently approved by the FDA for preventing osteoporosis. Its impact on the spine does not appear to be as powerful as either hormone replacement therapy or alendronate. There are no common side effects with raloxifene. Some women have experienced hot flashes and deep vein thrombosis (throm-boh-sis) (DVT), which is a blood clot in the leg.