Eight for 2008: Eight things you should know about osteoporosis and fracture risk
How strong are your bones? You may have no idea — until a bone breaks when you push on a stuck window or bend down to pick up something you've dropped. Fractures resulting from such seemingly innocuous activities — sometimes called fragility fractures — are usually the first symptom of osteoporosis, the skeletal disorder that makes bones vulnerable to breakage even without a serious fall or other trauma.
Osteoporosis is responsible for more than 1.5 million fractures each year in the United States, almost half of them vertebral (spine) fractures and the rest mostly broken hips and wrists. Hip fractures usually require hospitalization and surgery and often result in permanent disability or the need for nursing home care. Vertebral fractures not only are painful but also cause a stooped posture that can lead to respiratory and gastrointestinal problems.
Mostly a woman's disease
Of the estimated 10 million Americans who have osteoporosis, 80% are women. Another 22 million women are at increased risk for the disease. In both sexes, certain medications (glucocorticoids, aromatase inhibitors, immunosuppressive drugs, chemotherapy drugs, and anticonvulsants) can lead to significant bone loss. So can certain medical conditions.
Currently, a woman's odds of having an osteoporotic fracture are one in three. In order to do all we can to strengthen and preserve our bones, here are eight important points to keep in mind.
1. Vital nutrients
A healthy diet preserves bone strength by providing key nutrients such as potassium, magnesium, phosphorus, and — of course — calcium and vitamin D. If you don't get enough calcium, your body will take it from your bones. If your diet doesn't supply enough calcium (1,000 to 1,200 milligrams per day), take a supplement. The same goes for vitamin D, which is needed to extract calcium from your food. Food sources of vitamin D are limited, and you may not get enough sun to manufacture adequate amounts through the skin. Experts recommend 800 to 1,000 IU of vitamin D per day.
2. The exercise prescription
Two types of exercise — weight-bearing and resistance — are particularly important for countering osteoporosis. Weight-bearing activities are those in which your feet and legs bear your full weight. This puts stress on the bones of your lower body and spine, stimulating bone cell activity. Weight-bearing exercise includes running, jogging, brisk walking, jumping, playing tennis, and stair climbing. Resistance exercise — using free weights, rubber stretch bands, or the weight of your own body (as in sit-ups and push-ups) — applies stress to bones by way of the muscles. Merely occasional exercise won't help, though. Aim for at least 30 minutes of bone-strengthening exercise most days of the week.
3. No smoking, please
Women who smoke lose bone faster, reach menopause two years earlier, and have higher postmenopausal fracture rates. The mechanism isn't known; smoking may lower estrogen levels, or it may interfere with the absorption of calcium and other important nutrients.
4. Know your risk
The best way to assess fracture risk is to calculate bone mineral density (BMD) — the amount of calcium and other minerals in bone — at the spine and hip with low-dose x-rays (dual-energy x-ray absorptiometry, or DXA) and factor in a woman's age. The World Health Organization's definition of osteoporosis is based on a DXA value called a T-score, which compares the amount of bone a woman has to normal peak bone mass. A T-score of −2.5 or worse indicates osteoporosis.
Most official guidelines recommend DXA screening for all women starting at age 65, and earlier for women who take medications or have health conditions that increase osteoporosis risk. But reduced BMD is only one risk factor for osteoporosis. You're also at greater risk if you smoke or are older, Caucasian, or thin, or if you had a fracture after age 50 or have a parent who had a hip fracture.
5. Bone-preserving drugs
Postmenopausal woman who've had a fragility fracture or received a BMD T-score of −2.5 or worse should take an osteoporosis drug. Women with T-scores from −2.0 to −2.5 should consider drug therapy if they have a parent with a history of hip fracture or one or more other risk factors for osteoporosis.
All medications have side effects, and dosing schedules vary from one to the other, so it's important to explore all the options with your clinician.
6. Depression connection
Since the mid-1990s, researchers have investigated links between depression and bone loss. In 1996, a New England Journal of Medicine study found that women with a history of major depression had lower bone density at the hip and spine and higher levels of cortisol, a stress hormone associated with bone loss. It may be a long time before these connections are fully elucidated. In the meantime, women being treated for depression may want to talk to their clinicians about a BMD test.
7. Weight and weight loss
Weighing less than 127 pounds or having a body mass index under 21 is a risk factor for osteoporosis. Regardless of your body mass index, if you lose weight during the menopausal transition (late perimenopause and the first few years after menopause), you're more likely to lose bone. Avoid ultra-low-calorie diets and diets that eliminate whole food groups.
8. Avoiding falls
Falling is one of the leading causes of fractures, especially among older women and those with low BMDs. Clear floors of anything that could trip you, including loose cords, stools, pillows, throw rugs, and magazines. Make sure stairways, halls, and entrances are well lit; install night-lights to help you see your way to the bathroom. Add grab bars to your tub or shower; make sure stairways have sturdy handrails.
February 2008 update