Osteoporosis An Overview

[Michael Smithers]

Osteoporosis

National Institutes of Health Osteoporosis and Related Bone Diseases
National Resource Center

Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased risk of fractures of the hip, spine, and wrist. Men as well as women are affected by osteoporosis, a disease that can be prevented and treated.


Facts and Figures
* Osteoporosis is a major public health threat for 44 million Americans, 68 percent of whom are women.
* In the U.S. today, 10 million individuals already have osteoporosis and 34 million more have low bone mass, placing them at increased risk for this disease.
* One out of every two women and one in four men over 50 will have an osteoporosis-related fracture in their lifetime.
* More than 2 million American men suffer from osteoporosis, and millions more are at risk. Each year, 80,000 men have a hip fracture and one-third of these men die within a year.
* Osteoporosis can strike at any age.
* Osteoporosis is responsible for more than 1.5 million fractures annually, including 300,000 hip fractures, approximately 700,000 vertebral fractures, 250,000 wrist fractures, and more than 300,000 fractures at other sites.
* Based on figures from hospitals and nursing homes, the estimated national direct expenditures for osteoporosis and related fractures total $14 billion each year.

Risk Factors
Risk factors you cannot change
* Gender: Your chances of developing osteoporosis are greater if you are a woman. Women have less bone tissue and lose bone faster than men because of the changes that happen with menopause.
* Age: The older you are, the greater your risk of osteoporosis. Your bones become thinner and weaker as you age.
* Body size: Small, thin-boned women are at greater risk.
* Ethnicity: Caucasian and Asian women are at highest risk. African American and Hispanic women have a lower but significant risk.
* Family history: Fracture risk may be due, in part, to heredity. People whose parents have a history of fractures also seem to have reduced bone mass and may be at risk for fractures.

Risk factors you can change
* Sex hormones: Abnormal absence of menstrual periods (amenorrhea), low estrogen level (menopause), and low testosterone level in men can bring on osteoporosis.
* Anorexia nervosa: Characterized by an irrational fear of weight gain, this eating disorder increases your risk for osteoporosis.
* Calcium and vitamin D intake: A lifetime diet low in calcium and vitamin D makes you more prone to bone loss.
* Medication use: Long-term use of glucocorticoids and some anticonvulsants can lead to loss of bone density and fractures.
* Lifestyle: An inactive lifestyle or extended bed rest tends to weaken bones.
* Cigarette smoking: Cigarettes are bad for bones as well as the heart and lungs.
* Alcohol intake: Excessive consumption increases the risk of bone loss and fractures.

Prevention
To reach optimal peak bone mass and continue building new bone tissue as you age, there are several factors you should consider.

Calcium: An inadequate supply of calcium over a lifetime contributes to the development of osteoporosis. Many published studies show that low calcium intake appears to be associated with low bone mass, rapid bone loss, and high fracture rates. National nutrition surveys show that many people consume less than half the amount of calcium recommended to build and maintain healthy bones. Good sources of calcium include low-fat dairy products, such as milk, yogurt, cheese, and ice cream; dark green, leafy vegetables, such as broccoli, collard greens, bok choy, and spinach; sardines and salmon with bones; tofu; almonds; and foods fortified with calcium, such as orange juice, cereals, and breads. Depending upon how much calcium you get each day from food, you may need to take a calcium supplement.

Vitamin D: Vitamin D plays an important role in calcium absorption and in bone health. It is made in the skin through exposure to sunlight. While many people are able to obtain enough vitamin D naturally, studies show that vitamin D production decreases in the elderly, in people who are housebound, and for people in general during the winter. Depending on your situation, you may need to take vitamin D supplements to ensure a daily intake of between 400 to 800 IU of vitamin D. Massive doses are not recommended.

Exercise: Like muscle, bone is living tissue that responds to exercise by becoming stronger. Weight-bearing exercise is the best for your bones because it forces you to work against gravity. Examples include walking, hiking, jogging, stair climbing, weight training, tennis, and dancing.

Smoking: Smoking is bad for your bones as well as for your heart and lungs. Women who smoke have lower levels of estrogen compared to nonsmokers, and they often go through menopause earlier. Smokers also may absorb less calcium from their diets.

Alcohol: Regular consumption of 2 to 3 ounces a day of alcohol may be damaging to the skeleton, even in young women and men. Those who drink heavily are more prone to bone loss and fractures, because of both poor nutrition and increased risk of falling.

Medications that cause bone loss: The long-term use of glucocorticoids (medications prescribed for a wide range of diseases, including arthritis, asthma, Crohn’s disease, lupus, and other diseases of the lungs, kidneys, and liver) can lead to a loss of bone density and fractures. Bone loss can also result from long-term treatment with certain antiseizure drugs, such as phenytoin (Dilantin¹) and barbiturates; gonadotropin-releasing hormone (GnRH) drugs used to treat endometriosis; excessive use of aluminum-containing antacids; certain cancer treatments; and excessive thyroid hormone.

Detection
Following a comprehensive medical assessment, your doctor may recommend that you have your bone mass measured. A bone mineral density (BMD) test is the best way to determine your bone health. BMD tests can identify osteoporosis, determine your risk for fractures (broken bones), and measure your response to osteoporosis treatment. The most widely recognized bone mineral density test is called a dual-energy x-ray absorptiometry or DXA test. It is painless, like having an x ray, but with much less exposure to radiation. It can measure bone density at your hip and spine.

Treatment
Nutrition: The foods we eat contain a variety of vitamins, minerals, and other important nutrients that help keep our bodies healthy. All of these nutrients are needed in balanced proportion. In particular, calcium and vitamin D are needed for strong bones, and for your heart, muscles, and nerves to function properly.

Exercise: Exercise is an important component of an osteoporosis prevention and treatment program. Exercise not only improves your bone health, but it increases muscle strength, coordination, and balance, and leads to better overall health. While exercise is good for someone with osteoporosis, it should not put any sudden or excessive strain on your bones. As extra insurance against fractures, your doctor can recommend specific exercises to strengthen and support your back.

Therapeutic Medications: Currently, alendronate, raloxifene, risedronate, and ibandronate are approved by the U. S. Food and Drug Administration (FDA) for preventing and treating postmenopausal osteoporosis. Teriparatide is approved for treating the disease in postmenopausal women and men at high risk for fracture. Estrogen/hormone therapy (ET/HT) is approved for preventing postmenopausal osteoporosis, and calcitonin is approved for treatment.

Fall Prevention
Preventing falls is a special concern for men and women with osteoporosis. Falls can increase the likelihood of fracturing a bone in the hip, wrist, spine, or other part of the skeleton. In addition to the environmental factors listed below, falls can also be caused by impaired vision and/or balance, chronic diseases that affect mental or physical functioning, and certain medications, such as sedatives and antidepressants. It is important that individuals with osteoporosis be aware of any physical changes that affect their balance or gait, and that they discuss these changes with their health care provider. Here are some tips to help eliminate the environmental factors that lead to falls.

Outdoors:
* Use a cane or walker for added stability.
* Wear rubber-soled shoes for traction.
* Walk on grass when sidewalks are slippery.
* In winter, carry salt or kitty litter to sprinkle on slippery sidewalks.
* Be careful on highly polished floors that become slick and dangerous when wet.
* Use plastic or carpet runners when possible.

Indoors:
* Keep rooms free of clutter, especially on floors.
* Keep floor surfaces smooth but not slippery.
* Wear supportive, low-heeled shoes even at home.
* Avoid walking in socks, stockings, or slippers.
* Be sure carpets and area rugs have skid-proof backing or are tacked to the floor.
* Be sure stairwells are well lit and that stairs have handrails on both sides.
* Install grab bars on bathroom walls near tub, shower, and toilet.
* Use a rubber bath mat in shower or tub.
* Keep a flashlight with fresh batteries beside your bed.
* If using a step stool for hard-to-reach areas, use a sturdy one with a handrail and wide steps.
* Add ceiling fixtures to rooms lit by lamps.
* Consider purchasing a cordless phone so that you don’t have to rush to answer the phone when it rings, or
so that you can call for help if you do fall.