Porous Bone – Causes, Symptoms, Diagnosis, Treatment

Signs and Symptoms

Osteoporosis is sometimes considered a “silent disease” because bone loss occurs without symptoms. In fact, many people do not know they have the disease until they break a bone. Osteoporosis can also cause a vertebra (one of the 33 bony segments that form the spine) to collapse. Signs of a collapsed vertebra include:

• Back pain
• Loss of height
• Kyphosis, curvature of the spine that causes a humplike deformity

What Causes It?

Your bone strength and density is partly due to how much calcium and other minerals they contain. Your body is constantly making new bone and breaking down (reabsorbing) old bone. When you are young, this process happens quickly. You make more bone than you lose, so you build bone mass. After your mid 30s, your body continues to make new bone, but more slowly, causing you to lose more bone than you make. The amount of bone you have in your 30s helps determine your risk of developing osteoporosis later. For women, bone loss increases significantly at menopause, when estrogen levels drop. Although there are multiple causes of bone loss, genetic factors are responsible for 60 to 80% of peak bone mass.

Other than age and menopause, causes of osteoporosis can include:

• Long-term use of certain medications, particularly corticosteroids and thyroid medications (see “Warnings and Precautions” section)
• Cushing syndrome (when the adrenal glands produce too much of a hormone called cortisol)
• Kidney failure
• Diseases of the thyroid or adrenal glands
• Not getting enough calcium, vitamin D, vitamin A, vitamin K, and magnesium (however, high intake of vitamin A may actually increase the risk of osteoporosis)
• Anorexia nervosa
• Alcohol use disorder
• Rheumatoid arthritis

Risk Factors

Risk factors may include:

• Being female
• Having low estrogen levels (including after menopause)
• Being older. After age 75, the risk is the same for men and women
• Being of European, Hispanic, or Asian ancestry
• Living a sedentary lifestyle
• Being very thin
• Family history of osteoporosis. Genetic determinants are responsible for up to 85% of the variation in peak bone mass, and may also determine bone turnover and fracture risk.
• Late onset of menstruation or early menopause
• Smoking cigarettes, drinking too much caffeine, or drinking alcohol regularly
• Having irritable bowel syndrome
• Diet low in calcium and vitamin D or high in sodium
• Long-term use of certain medications, including corticosteroids, diuretics, aromatase inhibitors, and thyroid medications
• Exercise-induced amenorrhea (loss of menses)
• Having an eating disorder, particularly during the first 2 decades of life

Preventive Care

Osteoporosis can be prevented. Because your body builds bone mass until you are in your 30s, prevention should start early. Making sure you get enough calcium and vitamin D (required for your body to use calcium) is essential.

Weight bearing exercise, such as walking or lifting weights, as well as other exercises, including tai chi, can also help stave off the disease. Research shows that exercise early in life boosts bone mass, while exercise later in life helps maintain it. Exercise also increases strength, coordination, and balance. Experts recommend 1/2 hour of weight-bearing exercise daily. These are important tools to help prevent falls that cause fractures, especially in the elderly.

Other techniques for prevention include:

• Quitting smoking.
• Limiting caffeine to about 3 cups of coffee a day.
• For women, hormone replacement therapy (note that hormone replacement therapy has significant side effects, including increased risk of breast cancer, blood clots, and heart disease).

What to Expect at Your Doctor’s Office

If your doctor believes you are at risk for osteoporosis, they will order a bone mineral density test (BMD) to determine your bone mass. Several tests can measure bone density, and they are all painless, noninvasive, and safe. Some tests measure bone density in the spine, wrist, and hip (the most common sites of fractures due to osteoporosis), while others measure bone in the heel or hand.

The National Osteoporosis Foundation recommends a BMD for women who are not taking estrogen and:

• Use any medications that increase the risk of osteoporosis
• Had an early menopause
• Have a family history of osteoporosis, kidney disease, liver disease, or type 1 diabetes
• Are over 50, postmenopausal, and have at least one risk factor for osteoporosis
• Are over 65 and have never had a BMD
• BMD tests should be repeated every 2 to 5 years depending on the risk factors

Treatment Options

For those who are at risk for osteoporosis or already have the disease, treatment may help boost bone mass and prevent (further) bone loss. While calcium by itself does not cure or prevent osteoporosis, getting enough calcium is an essential part of any prevention or treatment program. Making lifestyle choices, such as eating a diet rich in fruits and vegetables and doing weight-bearing exercises can also enhance bone strength.

Lifestyle

Diet

Studies suggest that diets rich in the following foods and nutrients may help prevent bone loss in both men and women:

• Calcium. Low-fat milk, cheese, and broccoli are rich in calcium. Orange juice and cereals often are fortified with calcium
• Magnesium. Avocado, banana, cantaloupe, honeydew, lima beans, low-fat milk, nectarine, orange juice, potato, spinach
• Potassium. Whole grains, nuts, spinach, oatmeal, potato, peanut butter
• Vitamin D. The body makes vitamin D after exposure to sunlight. It is also found in fatty fish, fortified cereals, and milk.
• Vitamin K. Leafy greens, cauliflower
• Fruits
• Vegetables

Exercise

Exercise can help prevent bone loss. Although it is best to begin exercising when you are young (to help build bone), it is never too late to get the benefit. Weight-bearing exercise (walking, weight lifting) stimulates bones to produce more cells, slowing bone loss. Exercise also improves balance, flexibility, strength, and coordination, thereby reducing falls and broken bones associated with osteoporosis.

Drug Therapies

The standard treatment for osteoporosis for postmenopausal women used to be estrogen, but there are new options for men and for women who are wary of estrogen’s risks. Most medications slow down the rate at which bone is reabsorbed (antiresorptive). One drug can help the body make new bone (bone forming).

• Estrogen (with or without progesterone) boosts bone density and reduces the risk of fracture by slowing bone loss, boosting the body’s ability to absorb calcium, and reducing the amount of calcium excreted in the urine. Estrogen by itself can increase a woman’s risk for developing cancer in her uterine lining (endometrial cancer), so many doctors have prescribed a combination of estrogen and progesterone. However, evidence now shows that this combination increases a woman’s risk of breast cancer, ovarian cancer, blood clots, strokes, and heart attacks. Talk with your doctor to understand the risks and benefits of taking estrogen. There are other options for treating osteoporosis.
• Alendronate (Fosamax), ibandronate (Boniva), risedronate (Actonel), and zoledronic acid (Reclast). These medications belong to a class of drugs known as bisphosphonates. These drugs have been shown to boost bone density, slow or stop bone loss, and reduce the risk of fractures. Side effects are uncommon but may include abdominal pain and heartburn, which can be reduced by taking the medications with 8 oz. of water first thing in the morning before eating anything else, and standing upright for at least 30 minutes after taking them. Reclast is given intravenously (IV).
• Raloxifene (Evista), from a class of drugs called Selective Estrogen Receptor Modifiers (SERMS), raloxifene has estrogen-like effects on bone (it prevents bone loss), but does not increase the risk for breast cancer. Side effects can include hot flashes and blood clots. Premenopausal women should not take raloxifene.
• Calcitonin (Miacalcin) does not improve bone density as well as the bisphosphonates, but it does slow bone loss, reduce spinal fractures, and ease pain associated with bone fractures. An alternative for women who cannot take estrogen or bisphosphonates.
• Parathyroid hormone (Forteo) used in low doses, this drug can increase bone production. It can only be taken by injection. It is often prescribed for postmenopausal women and men at risk of fracture. Children should not take parathyroid hormone.

Surgery and Other Procedures

A procedure called kyphoplasty can treat kyphosis, the humplike deformity sometimes caused by osteoporosis. A catheter inserts a balloon into the middle of a collapsed vertebra and then expands so the height of the vertebra is restored. The surgeon then injects bone cement into the vertebra to hold its shape. Vertebroplasty is another procedure in which cement is injected into the vertebra to reinforce it.

Complementary and Alternative Therapies

Nutrition and Supplements

Eating fruits and vegetables and consuming adequate amounts of calcium and vitamin D are crucial in the prevention and treatment of osteoporosis. Keeping bones healthy throughout life depends on getting enough of specific vitamins and minerals, including phosphorous, magnesium, boron, manganese, copper, zinc, folate, and vitamins B12, B6, C, and K. Avoiding sodium, alcohol, and caffeine will also enhance bone health.

Calcium: Calcium helps the body build bone. Recommended intakes of calcium are as follows (note that you generally get from 500 to 700 mg of calcium in your diet):

• Children: 800 to 1,200 mg/day
• Adolescent girls: 1,200 to 1,500 mg/day
• Premenopausal women (19 to 50 years old): 1,000 mg/day
• Older adults (51 to 70 years old): 1,200 to 1,500 mg/day

The recommended intake for older women is 1,500 mg/day, except for those on estrogen, who need only 1,000 mg/day.

Good dietary sources of calcium include:

• Low-fat dairy products (such as milk, yogurt, and cheese)
• Dark green, leafy vegetables (such as broccoli, collard greens, and spinach)
• Salmon
• Tofu
• Almonds

If you do not get enough calcium from food alone, you may want to take a calcium supplement. There are several varieties available. Ask your doctor which one is right for you:

• Calcium citrate (Citrical, Solgar) most easily absorbed and costs more
• Calcium carbonate (Tums, Caltrate, Rolaids) least expensive and must be taken with meals or a glass of orange (acidic) juice; may cause gas or constipation
• Calcium phosphate (Posture) easily absorbed, does not cause stomach upset; more expensive than calcium carbonate

Calcium supplements should be taken in divided doses during the day, because your body can only absorb 500 mg of calcium at a time. Work with your doctor to make sure you get enough, but not too much, calcium, especially if you are taking any medications.

Vitamin D: In order to absorb enough calcium, your body also needs vitamin D. The National Osteoporosis Foundation recommends the following:

• Adults under age 50: 400 to 800 IU/day
• Older adults (51 to 70 years old): up to 2,000 IU/day

Vitamin K (150 to 500 mcg): Vitamin K, which the body makes in the intestine, helps bind calcium into bone. A recent study suggests that at menopause, vitamin K may start to lose its ability to bind calcium, so even women with normal levels of vitamin K may not have enough to maintain bone health. Eating 3 servings of low-fat dairy or dark, leafy greens per day can help. Talk to your doctor about whether you need a supplement. However, be especially careful about taking a supplement if you also take blood-thinning medications (diuretics), such as warfarin (Coumadin), aspirin, and others, because vitamin K may interact with these medications.

Soy isoflavones: Isoflavones are phytoestrogens, plant chemicals that have some of the same effects as estrogen. Because estrogen helps protect against osteoporosis, researchers theorize that isoflavones may also help stop bone loss. Studies are conflicting, however. The best source of soy isoflavones is through diet (tofu, soy milk, and soybeans). When isoflavones are eaten in foods, they do not appear to have the same negative effects that supplemental estrogen does. If you have a history of hormone-related cancer, talk to your doctor before taking soy. Soy contains phytic acid, which may block the aborption of calcium and other critical minerals.

Ipriflavone (600 mg per day): Ipriflavone, a synthetic isoflavone derived from natural isoflavones found in soy, red clover, and other food sources, may also help prevent and treat osteoporosis. Most studies, though not all, indicate that ipriflavone, when combined with calcium, can slow bone loss and help prevent fractures of the vertebrae (spine) in postmenopausal women. Talk to your doctor before taking ipriflavone.

Omega-3 fatty acids, such as those found in fish oil (4 g per day): A few studies have shown that supplements containing essential fatty acids, such as those found in fish oil, can help maintain or possibly increase bone mass. Essential fatty acids appear to increase the amount of calcium your body absorbs, diminish the amount of calcium lost in urine, improve bone strength, and enhance bone growth. Foods rich in essential fatty acids (including cold-water fish, such as salmon) can help raise the amount of essential fatty acids in your diet. People who are taking blood-thinning medication (anticoagulants) should not take fish oil supplements without talking to their doctor first.

Preliminary studies also suggest that the following nutrients may help prevent or treat osteoporosis:

• Carotenoids. Studies show that carotenoids protect bone mineral density in older men and women
• Zinc stimulates bone formation and inhibits bone loss in animals.
• Vitamin C may limit bone loss in early years of menopause. Studies show mixed results.
• Melatonin is involved in bone growth. Since levels of melatonin drop as you age, it is possible that melatonin may contribute to the development of osteoporosis. More studies are needed. People who take antidepressants or psychiatric medications should not take melatonin without a doctor’s supervision.

(See the “Warnings and Precautions” section for a list of supplements that people with osteoporosis should avoid.)

Herbs

Although most herbs have not been studied extensively for the treatment of osteoporosis, some have estrogen-like effects that might offer protection against bone loss. However, they may also carry some of the same risks as supplemental estrogen. They may also interact with blood-thinning medications, such as warfarin (Coumadin) and others. Talk to your doctor before taking any of these herbs.

• Black cohosh ( Actaea racemosa or Cimicifuga racemosa ). Black cohosh contains phytoestrogens (estrogen-like substances that help protect against bone loss). It is often used to relieve menopausal symptoms, although evidence for its effectiveness is mixed. People who have a history of hormone-related cancers, or have a high risk of developing hormone-related cancers (such as breast cancer, among others) should not take Black cohosh except under the supervision of your physician.
• Red clover ( Trifolium pratense ). Isoflavones extracted from this herb may slow bone loss in women, but it is not clear whether the whole herb is effective. More tests are needed to prove its effectiveness. Red clover may possibly interact with several medications, and due to its estrogen-like effects. If you have a history of hormone-related cancers, or are at high risk for such cancers, you should not take Red clover except under the supervision of your physician.

Other herbs that may help prevent or treat osteoporosis (evidence is lacking so far) include:

• Horsetail ( Equisetum arvense ) contains silicon, believed to strengthen bone
• Kelp ( Fucus vesiculosus L .) used for musculoskeletal disorders; rich in minerals so may be a complementary treatment for osteoporosis
• Oat straw ( Avena sativa ) boosts hormone levels that stimulate cell growth

Special Considerations

Warnings and Precautions

Some studies suggest that too much vitamin A may increase the risk for osteoporosis. People with osteoporosis, or those at risk for the disease, should not exceed the daily recommended intake of vitamin A (900 mcg/day for men and 700 mcg/day for women).

Certain medications may contribute to the development of osteoporosis when used for long periods of time:

• Corticosteroids (steroid hormones)
• Thyroid medications
• Blood thinners
• Diuretics (water pills)
• Antibiotics
• Immune system suppressants
• Aluminum-containing antacids

Talk to your doctor if you take any of these medications.

Prognosis and Complications

Bone fractures are the most common complications of osteoporosis and are a significant cause of disability and death. After age 60, 25% of women have a spinal fracture. That percentage doubles after age 75. By age 90, 33% of women and 17% of men have had a hip fracture, usually from a minor fall or accident. Many elderly people who suffer a hip fracture lose the ability to walk and, most significantly, up to 36% die within one year.

Although about 2 million bone fractures in the U.S. each year result from osteoporosis, most are preventable. Several medications are currently being researched that may expand the treatment options available to people with osteoporosis. In the meantime, a combination of medications, diet, exercise, and calcium and vitamin D supplements can help slow the progression of the disease.