Boning Up

Since osteoporosis is so common among postmenopausal women, it’s important to understand its risk factors, diagnosis and treatment options.
Christie Underwood uses exercise to address osteoporosis, for which she received a diagnosis in 2020.
Christie Underwood uses exercise to address osteoporosis, for which she received a diagnosis in 2020. Graphic by Debbie Hurst.

When Christie Underwood looks at the older women squatting, lunging and stretching to popular oldies in her “Easy Fit” class, she assumes the vast majority either have or may develop osteoporosis. That’s because she knows how common it is among post-menopausal women—and because she has it herself.

The 56-year-old trainer was diagnosed with osteoporosis in 2020 after her doctor noticed she had lost an inch in height. A bone density scan confirmed it. “I was in shock, especially because I am so active,” she says of the result. “I have taken all kinds of fitness classes my whole life. My doctor said, ‘You can thank your grandmother for that.’”

Susan Forrer, 63, was diagnosed with osteoporosis in 2010, a year after being treated with chemotherapy for breast cancer. Some cancer treatments can put women into early menopause, resulting in lower estrogen levels, which can lead to osteoporosis.

In Forrer’s case, it also led to a broken ankle while she was walking in downtown Sacramento in 2017.

“I always think about it now when I’m walking downtown,” she says. “Any little trip and I think, ‘Oh, no!’ But it doesn’t stop me from doing what I want to do.”

And Carol Greenfield, now in her 70s, was diagnosed more than 20 years ago.

“I’m in the demographics for bone loss—slender and Caucasian,” she says. “I used to be 5 foot-4, and they told me I had shrunk.”

The Bone Health and Osteoporosis Foundation estimates that half of all women over age 50 will eventually develop osteoporosis. About 80 percent of Americans with the disease are women. And 43 percent of Americans over 50 have low bone density or osteopenia, although some experts say it’s likely even more prevalent.

For these adults, bone loss and the risk of fractures are an ever-present worry, and their prevention is key to a healthy, high-quality life. Many others, left undiagnosed, have no idea how vulnerable they are to broken bones or their potentially devastating consequences.

CAUSES AND RISK FACTORS—To understand osteoporosis, it’s helpful to know that bone growth—the formation of the skeleton—typically ends before age 25. How much bone a person forms depends on genetics, the amount of physical activity and the consumption of nutrients in childhood and adolescence, when bones are forming.

“After about 20 or 25 years old, you have the highest bone mass you will have in your life,” says Nancy Lane, M.D., distinguished professor of medicine and rheumatology at UC Davis Health. “Women hang onto that bone until about 50 and go through menopause, and men until they are about 70, as long as they remain active, eat a balanced diet and don’t have an illness that results in a significant loss of weight or for which they are prescribed medicines that eat away at bone.”

Like any living tissue, bone remodels to stay strong. This highly orchestrated process is initiated by bone tissue cells that signal it’s time for old bone to break down, carried out by cells called osteoclasts. New bone forms in its place by cells called osteoblasts.

Because estrogen plays an important role in the remodeling process, estrogen loss during menopause causes an imbalance between resorption and formation, resulting in bone loss and a higher risk of osteoporosis and fracture. One in two women will at some point break a bone because of osteoporosis. In men, who don’t generally lose estrogen, remodeling problems don’t start until about age 70; one in four men will break a bone because of osteoporosis.

COMMON, BUT UNDERTREATED—While osteoporosis is extremely common, it’s often missed in older people, even after treatment for a broken bone.

“We have made spectacular gains,” says Michael McClung, M.D., an endocrinologist and founding director of the Oregon Osteoporosis Center, who has served on numerous national and international bone health panels. “When we first began our clinic 35 years ago, we had no definition of osteoporosis, no diagnostic tools, no therapies that we knew were effective.”

While all that has changed, he adds, “collectively, we are doing terribly in terms of applying these gains we have made in terms of daily clinical care. It is very frustrating to observe that the advances are not being used.”

The problem, he says, is that the medical field poorly understands the relationship between a woman’s post-menopausal fracture and osteoporosis.

Lane agrees. “The biggest problem we have today in osteoporosis is identifying the patients who have fractures and then getting them treated,” she says. “Because today, unlike 30 years ago, we actually have very good and effective medications to prevent and treat osteoporosis.”

FINDING YOUR RISK—Today, providers have tools to determine who is at risk for osteoporosis and may benefit from treatment. The Fracture Risk Assessment Tool, released by the World Health Organization in 2008, uses an algorithm to calculate a person’s 10 year risk of an osteoporotic fracture in the spine, upper arm, wrist or hip. The FRAX considers gender, age, weight, height, tobacco or alcohol use, and family history. It also asks about glucocorticoid drug use or health conditions strongly linked to osteoporosis.
The bone density scan, or DEXA, compares the patient’s bone density with the average peak bone density of a healthy young adult of the same gender and ethnicity (the T score). The difference is calculated as a standard deviation from normal. A T score of -2.5 standard deviation is considered osteoporosis; between -1 and -2.5 is considered low bone density, also called osteopenia.

McClung says women should get a bone density test when they hit menopause.

“We know that the level of bone density women have at the time of menopause is the strongest indicator of their likelihood of developing osteoporosis later on,” he says, adding that women lose on average 10 to 12 percent of their bone mass during the menopausal transition.

BONE LOSS TREATMENT—Once diagnosed, women at risk for osteoporosis can take estrogen to prevent further bone loss, McClung says, but if the treatment is discontinued, its benefits end and bone loss resumes. Because long-term estrogen therapy has been linked with breast cancer, it’s not recommended for women at high risk for the disease, he adds.

While no osteoporosis drug is recommended for lifelong use, and all have possible side effects, many treatments available today are effective in keeping bone loss from progressing. They fall into two main categories: anti-remodeling drugs, also called anti resorptive drugs, and anabolic steroid drugs.

Anti-remodeling drugs include bisphosphonates like Fosamax, Reclast and Boniva. These work by inhibiting the resorption of bone. These drugs can boost bone density but don’t restore the bone’s damaged architecture. In very rare cases, bisphosphonates can cause atypical fractures of the femur, as well as jaw necrosis, a condition in which jawbone cells break down. Both conditions are treatable.

“We recommend the (oral) bisphosphonates for five years and intravenous medications (zoledronic acid, or Reclast) for three years, and then patients need to be re-evaluated,” says Lane. “If bone mass has increased, and the patient has not had a fracture, then they may get a drug holiday.” She says treatments may resume later if bone loss is again detected.

“Osteoporosis is a chronic disease like hypertension,” Lane explains. “You always have it, but we treat it to reduce your risks of fracture.”

Physicians may also recommend anabolic medications, which stimulate osteo blasts to lay down new bone. The two most common of these are teriparatide (Forteo) and abaloparatide (Tymlos), which require that patients give themselves daily injections for one and a half to two years. Patients will lose the bone mass they’ve gained when they stop the drug if they don’t start a course of bisphosphonates.

That is what happened to Greenfield, who took bisphosphonates for years for
osteopenia before her doctor says she should stop them. She didn’t think much about it until a few years later, in 2020, when she took a spill and fractured her sacrum in two places. By then, she says, she had osteoporosis. Afraid to go back on bisphosphonates, she looked for other options. After some research, she found Lane, who prescribed a new type of osteoporosis drug called Romosozumab (Evenity). Evinity both stimulates the osteoblasts to make more bone and inhibits bone resorption.

“The good news is that in 10 or 11 months my T score went from a -3 to a -2,” she says. But as with other treatments, Greenfield had to stop the medication after two years and has since returned to taking Fosamax, a bisphosphonate.

“The wonderful part about our treatment menu is that we have drugs with multiple different mechanisms of action,” says McClung.

Doctors also recommend that women with bone loss take good care of their bodies.

“Bone is an organ that needs nutrition, calcium, vitamin D and exercise to stay healthy,” says Lane. You won’t see increases in bone mass, but you will see a more resilient bone. And if you exercise and you do fall, you may not fracture.”

Underwood and Forrer, both of whom are on bisphosphonate drugs, also engage in regular exercise and take supplements. Forrer gets strength and resistance training, walks regularly and takes calcium.

Underwood, who has suffered a broken metatarsal and toes since her diagnosis, is especially focused on balance training, to reduce her risk of falling, and strength training, to ensure that if she falls, she is strong enough to catch herself and prevent a bad outcome.

As Underwood’s “Easy Fit” class closes with gentle stretching, she takes comfort in knowing she’s not the only one in the room at risk of fracture reaping the benefits.