No matter what some of us may imagine, osteoporosis isn't just a disease of a few frail white-haired ladies.
Also called brittle bone disease, it threatens more than 28 million Americans. Young and old. Men and women. About 10 million people have it, and an additional 18 million have the low bone mass that precedes it. Although osteoporosis is linked to a decline in the female hormone estrogen, about 20 percent of sufferers are men.
Results of an ongoing national study recently revealed that more than half of postmenopausal women older than 50 with no history of the disorder either had thinning bones or outright osteoporosis. Doctors warn that younger, weight-obsessed women who cut out milk, cheese and other sources of calcium are setting themselves up for a rude awakening before they reach their golden years.
"Half a bagel for breakfast, lettuce for lunch and just yogurt for dinner ... can have significant repercussions on their health later," says Dr. Aurelia Nattiv, director of the University of California, Los Angeles, Osteoporosis Center.
Osteoporosis results in poor posture, pain and 1.5 million osteoporosis related fractures annually. The bone tissue disorder occurs when older bone cells break down faster than they can be replaced with new bone.
Although white women were long considered at highest risk, the National Osteoporosis Risk Assessment study -- the largest study of its kind to date -- found low bone mass and osteoporosis among greater proportions of postmenopausal Asian, Latino and Native American women.
Think of bone mass as money in the bank. If you don't make deposits and earn interest over the years, you can run short later. About 90 percent of peak bone mass is accumulated by age 18; adults hit their peak by age 30.
In growing numbers of teen-agers and college athletes, excessive dieting is eroding the very bone they should be building for adulthood. Young dieters often skip foods needed to strengthen their skeletons. If they're also sedentary, they're missing bone-fortifying exercise.
At the other extreme -- and at particular risk for early osteoporosis -- are female athletes such as distance runners who have eating disorders or poor nutritional habits, and train to the point that their menstrual periods started late or have stopped prematurely, Dr. Nattiv says. As a UCLA team physician, she screens for signs of bone loss, such as stress fractures.
"We've seen women in their 20s that have bone density of women in their 50s, 60s and 70s. In some cases we're ... talking about real osteoporosis in a 20-year-old," Dr. Nattiv said. Treatment choices are limited because many medications are not recommended for women of childbearing age. Dr. Nattiv advises them to train less intensely and eat a more balanced diet whichincludes calcium. In some cases, she puts them on hormone therapy.
So if the numbers and risks of osteoporosis are so high among so many segments of the population, why is the disorder so underdiagnosed?
It boils down to this: Osteoporosis is a silent disease.
Typically, sufferers may have no pain and no clue until they break a hip, snap a wrist or suffer tiny spinal fractures that sometimes leave them with a dowager's hump or pare a few inches from their height. The breaks are complicated by the accelerated bone loss that comes with declining estrogen. Broken hips often initiate a downward spiral of lost mobility and illness, culminating in death. About 15 percent of white women will break hips, and the injury will prove fatal in 10 percent to 20 percent of those cases.
Broken bones got Judy Beth Dare's attention.
The Walnut, Calif., resident developed back pain in April, three months after a liver transplant. Although she was warned that the steroid prednisone in her post-transplant regimen wasn't good for bones, she didn't suspect osteoporosis.
Neither did doctors, said Ms. Dare, 57.
"Then they did an X-ray and found some of the vertebrae were fractured," she said.
Her bones had weakened dangerously, and she began taking alendronate, marketed as Fosamax, which increases bone mass and reduces fractures. Ten months later, Dare is feeling fine.
She was fortunate enough to benefit from current wisdom. Early detection and lifestyle changes can halt bone loss before it progresses to osteoporosis. And drug treatment can reverse losses or, at the very least, stabilize bone mass.
Doctors hope the national study, which aims to measure bone density in 200,000 women, will improve understanding of the relationship between bone mass, disease and fractures. They also hope it will convince more primary-care doctors to test patients.
"Clearly, a very small percentage of women are being screened in the primary-care setting," said Dr. Ethel Siris, director of the osteoporosis program at Columbia Presbyterian Medical Center in New York and the medical director of the study. "We have to make risk assessment for osteoporosis a routine part of care. We've got the diagnostic tools. We've got the drugs. We've got compelling data telling us this is a significant issue for aging women," she said. "If you wait for somebody to fracture before you diagnose, it's like waiting for somebody to have a stroke before treating high blood pressure."
In the fall, the National Osteoporosis Foundation issued its first treatment and diagnosis guidelines, which recommended testing all women 65 and older, regardless of risk factors. Postmenopausal women with one or more risk factors for fracture should be tested, as should all postmenopausal women who have suffered broken bones, the foundation said.
"You need to know what your risk factors are for screening," Dr. Nattiv said.
There are several approaches to preventing osteoporosis. Everyone should maximize bone density by getting sufficient calcium and vitamin D, exercising regularly, and avoiding smoking and heavy drinking. But once significant bone loss is diagnosed, calcium and vitamin D supplements can slow the depletion and reduce fractures.