Skip to content
My WebMD Sign In, Sign Up

Osteoporosis Health Center

Font Size

Osteoporosis: On the Cutting Edge of Bone Health

Advances in research are changing the way osteoporosis experts think about this widespread disease.

Understanding Bone Remodeling

Bisphosphonate drugs were originally thought of as osteoporosis treatments that helped to build bone mass. But it soon became clear that something more was going on here. Many patients taking bisphosphonates may see only a modest increase in bone density -- as little as 1% -- and yet they have a much greater reduction in their risk of fractures, as much as 50%.

"Research has shown that there is no relationship between how much these drugs build bone mass and the reduction in fracture risk," says Robert Heaney, M.D., a professor of medicine at the Osteoporosis Research Center at Creighton University School of Medicine in Omaha, Neb.

Scientists realized that the drugs were also slowing down the rate of bone remodeling -- the process in which existing areas of bone is pared away, later to be replaced with new bone. In menopausal women, that rate of bone remodeling doubles -- and then it triples by a woman's early 60s.

"Imagine if you started remodeling your house: first you put an extension on one side, but before you finished that, you decided to tear out the garage, and before finishing that, you decided to put a deck on," says Heaney. "You'd have a pretty fragile house. That's what's happening with accelerated bone remodeling."

Now that they understand the importance of bone remodeling, osteoporosis experts are trying to use that knowledge to help predict osteoporosis risk factors. They're developing tools known as biomarkers, which are chemical measures of the rate of bone remodeling that can be found in secretions from blood or urine. There are already biomarkers for the rate of bone remodeling that work very well in large population studies, says Heaney, but they do not yet have markers that work well in the doctor's office, on an individual patient level. Once more accurate biomarkers are developed, these and advanced imaging techniques may enormously improve our understanding of who is at greatest risk from osteoporosis.

"This allows us to focus on where the problem really lies: the excess remodeling that's making bone fragile," Heaney says.

New Osteoporosis Treatments

A few years ago, Heaney saw an 18-year-old girl who'd been in a serious car accident. She'd escaped with only a few bruises, and X-rays revealed that she had unusually high bone density. It turned out that her mother, too, had bone density well above the average. Heaney and his colleagues at Creighton began studying the entire family -- over 150 people -- and eventually identified what they call the "high bone mass gene."

A particular mutation in this gene causes the body to make abnormally high amounts of a protein called LRP5 (low density lipoprotein receptor-related protein 5). LRP5 influences how much bone is formed and maintained. "None of the people with the high bone mass gene had ever broken anything, even if they'd fallen off the barn roof," says Heaney.

Today on WebMD

Women working out and walking with weights
Reduce bone loss and build stronger muscles.
Chinese cabbage
Calcium-rich foods to add to your diet.
woman stretching
Get the facts on osteoporosis.
Porous bone
Causes, symptoms, risk factors, and treatment.
Lactose Intolerance
Woman holding plate of brocolli
Dairy products
Superfood for Bones
Screening Tests for Women
exercise endometrial cancer
hand holding medicine
Working Out With Osteoporosis