While bones strengthen and grow with the help of new cells, they also release minerals, such as calcium, that the body needs, and break down to clear the way for new bone. As we age, we tend to lose more bone than we replace, and that can put us at risk of osteoporosis.
When seen through a microscope, healthy bones look like a honeycomb. With osteoporosis—which literally means “porous bone”—bones lose density, so the holes and spaces in the honeycomb-like structure grow larger, causing the bones to be weaker and more susceptible to breaking.
Our diet and exercise as children, adolescents and adults can influence our risk later in life for developing osteoporosis—or osteopenia, a type of bone loss that’s less severe than osteoporosis. Some doctors even refer to osteoporosis as a “pediatric disease with geriatric consequences.”
“When we’re younger, we have a chance to strengthen bones and the muscles that support our skeleton,” says Philip Wright, MD, a radiologist at Sentara RMH Medical Center. “Strengthening early on in life is important, so that when we begin to lose bone and muscle mass, our baseline strength is higher.”
Girls reach about 90 percent of peak bone mass by age 18, and boys by age 20. Bone mass can continue to build until about age 30, according to the National Institutes of Health.
Who Gets Osteoporosis?
Women are more likely than men to be diagnosed with osteopenia and osteoporosis. In fact, about one in three women over 50 will be diagnosed with one condition or the other. Among men over 50, the rate is about one in five, Dr. Wright says.
According to the National Osteoporosis Foundation, approximately 7.5 million women and 1.5 million men in the United States currently have osteoporosis.
Risk factors for osteoporosis include the following:
Age: The disease is more common in older people.
Gender: Women are more likely than men to be diagnosed.
Menopause: Estrogen protects bones. When estrogen levels drop after menopause, women often experience bone loss. In fact, women can lose up to 20 percent of their bone density within 5-7 years after menopause. Women who have had their ovaries removed also are at a greater risk, since the ovaries produce estrogen.
Family history: Heredity and genetics are significant factors in osteoporosis.
Inactive lifestyle: Exercise helps to build bone and muscle mass.
Some medical conditions: Autoimmune disorders, digestive and gastrointestinal disorders, endocrinal and hormonal disorders, breast cancer treatment, prostate cancer treatment, and eating disorders can contribute to bone loss.
Certain medications: Steroids, certain anticancer drugs, antacids, antianxiety drugs and anticoagulants are among the medications linked to bone loss.
How is Osteoporosis Diagnosed?
Apart from broken bones, people don’t usually show symptoms of osteopenia or osteoporosis, says Dr. Wright. Since we can’t feel our bones getting weaker, it’s very much a “silent” disease with few outwardly noticeable signs.
That’s why doctors recommend a bone-density scan for high-risk populations. The National Osteoporosis Foundation recommends scans for all women over 65. Some doctors also recommend that women receive a scan after menopause starts in order to establish a baseline for bone strength, which can be used later to assess any potential weakening in the patient’s bone structure.
Beyond those guidelines, doctors may recommend a scan for postmenopausal women not on hormone replacement, adults suffering fractures following minimal trauma, and patients on chronic steroids, among other factors. Scans are usually scheduled every two years.
According to Dr. Wright, a dual-energy X-ray absorption (DEXA) scan to measure bone strength uses two low doses of radiation, representing just one-tenth of the radiation used in a standard chest X-ray.
“It’s one of the easiest tests to go through,” adds Theresa Hinz, the lead bone density tech at Sentara Martha Jefferson Hospital.
After patients fill out a medical history sheet, the actual test takes about 15 minutes, Hinz explains. Patients should wear comfortable clothing without any metal at the waist or hip. They should tell their tech about any prior implanted surgical devices, hip replacements and back surgeries. Patients also cannot have had any test that involves contrast, a chemical substance given to patients to make certain body parts show up on X-rays, less than a week before a DEXA scan.
During the scan, the patient lies on a table on his or her back, with a pillow under the head.
“The three places where elderly people generally show fractures first are the hip, lumbar spine and wrist,” Hinz notes. “These are the weakest points, so we scan those.”
Crunching the Numbers
Radiologists use computer models to score DEXA scans and determine whether the patient has osteopenia or osteoporosis.
The patient’s T-score compares his or her mineral bone density to that of a healthy 30-year-old of the same gender. The Z-score, on the other hand, compares the patient’s bone density to that of other people of the same age, Dr. Wright says. The lower the T-score and Z-score, the more porous the bone.
To make a diagnosis, doctors also will conduct a physical exam and may order blood and urine tests, along with reviewing the patient’s medical history.
Adults represent the vast majority of patients diagnosed with osteoporosis or osteopenia, Dr. Wright says. Children can be diagnosed if they have certain diseases or genetic conditions, such as cerebral palsy or muscular dystrophy.
Patients with anorexia are also at greater risk of osteoporosis. Given their poor diet, they may not ingest enough calcium and vitamin D, and a low weight can cause the body to stop producing bone-protecting estrogen.
Living with Osteoporosis
After a diagnosis of osteoporosis, treatment can include medication, calcium and vitamin D supplements, weight-bearing exercises, and an overall healthier lifestyle.
“Exercise is one of the biggest factors, especially weight-bearing exercise,” Hinz says. “But people with osteoporosis should avoid heavy lifting.”
Patients should talk to their doctors about the appropriate amounts of calcium and vitamin D they need, she says. The body can absorb only 500-600 milligrams of calcium at a time.
Minimizing one’s risk of falling is also important to preventing broken bones. Patients with osteoporosis can help protect themselves from falling by adding hand rails in key locations; removing throw rugs and other trip hazards; and keeping stairs, halls and other walkways well-lit and clear of clutter. Improving one’s balance also can reduce the chance of falling.
“Bone loss is natural in older adults, but it can be limited and treated,” Hinz says. “However, getting evaluated for osteoporosis early—before a break occurs—is key to long-term bone health.”
Building Bone Strength
Calcium and Vitamin D: Calcium strengthens bones, and bones also serve to store calcium for the body. Since the body doesn’t produce calcium, it has to get the calcium it needs from foods and supplements. Vitamin D helps the body absorb calcium.
Weight-Bearing Exercise: Exercise strengthens bones by stimulating cell growth. And since muscles support our bones, they’re also important to overall bone health. The National Osteoporosis Foundation recommends 2 ½ hours of exercise per week to help maintain strong bones.
Weight-bearing exercises include walking, jogging, aerobics, hiking, tennis, the use of elliptical machines, yoga and Pilates. Lifting weights is also an option, depending on your overall health. While swimming is a healthy exercise, it is not considered to be a weight-bearing activity.
Lifestyle: Exercise regularly, don’t smoke, and limit your alcohol intake. Also limit caffeine intake, since caffeine can interfere with the body’s ability to absorb calcium.
Healthy Weight: Underweight women may not be getting enough calcium and vitamin D, and may not produce enough estrogen, which is important for bone health.