Boning Up on Bone Loss

As people age, their bones often lose density and mass and become brittle and vulnerable to fracture, a condition we call osteoporosis. It is most commonly seen in postmenopausal women but may also develop in men.

There are a variety of medications to help slow or prevent bone loss, but they each have side effects that must be weighed against their benefits. A newly published investigation offers an analysis of nearly 300 studies of the various drugs available to prevent the progression of osteoporosis.

There are steps you can take to decrease the occurrence and impact of this disease.

Osteoporosis may also occur in men and women with certain medical conditions such as rheumatoid arthritis or who are on medications such as steroids. Other risk factors include a family history of fractures, race (it is more common among people of European and Asian descent), cigarette smoking, low body weight, and, as mentioned earlier, increasing age.

As bones become less dense, the risk of fractures increases. This risk is heightened because the elderly often fall — from poor balance, decreased muscle strength, poor eyesight, heart problems, and other causes.

The spine, the ribs, hips, shoulders, and wrists are the most common locations for fractures. When fractures do occur, they often cause the person significant disability and loss of independence. They can also lead to other serious and painful health complications such as spinal cord compression symptoms, deep vein thromboses, and infections.

Osteoporosis has no symptoms in its early stages. Bone loss can be discovered before a fracture occurs by a bone mineral density test. The results of this test are reported as T-scores. These scores are based on a comparison of an older (65+) person's bone density with that of healthy young women. A T-score of -1.0 or higher is normal. A T-score between -1 and -2.49 indicates the early thinning of bones. T-scores of -2.5 or more indicate osteoporosis.

There are steps you can take to decrease the occurrence and impact of this disease. The National Osteoporosis Foundation (NOF.org) recommends getting enough calcium and vitamin D, controlling the amount of protein, sodium and caffeine in your diet, maintaining an active life style, avoiding smoking and excessive alcohol, maintaining a healthy body weight.

If a person has a very low T-score, or has experienced an osteoporosis-related fracture, or is judged to be at high risk for fractures, they are usually prescribed medications to reverse or prevent progression of bone loss. There is a wide range of medications for osteoporosis. They vary in the way they act on the body, how they are administered (pills, injections) and how often they are administered (daily, monthly, yearly).

Certain medications for other conditions can have a negative effect on bone mass — some antacids and protein pump inhibitors (PPI), some antidepressants, some hormone preparations, chemotherapy drugs, among others. If you have been prescribed drugs that are known to contribute to a loss of bone density, you need to let your healthcare provider know so she can discontinue or alter the dose of these medications. It can be a delicate balancing act, and a doctor's oversight can help patients select the best drugs for their situation.

Because there are quite a few drugs to choose from and each has strengths and weaknesses, a recent study looked at the drugs used to slow bone loss in an effort to help shed some light on the decision-making process. The researchers reviewed 294 articles that reported on studies of effectiveness and side effects of osteoporosis drugs and summarized the data.

One major class of drugs that are used to treat osteoporosis is the bisphosphonates. Some examples are: alendronate (Fosamax, Binosto), risedronate (Actonel, Atelvia), ibandronate (Boniva), zoledronic acid (Reclast, Zometa).

Choosing among the options can be challenging as each class of medications is associated with a range side effects from bothersome to potentially disabling.

A second category are hormone-related medications such as the estrogens used for hormone replacement therapy and raloxifene (Evista) which is similar to estrogen without some of the associated risks. Additionally, teriparatide (Forteo) is similar to parathyroid hormone and acts to stimulate new bone growth and denosumab (Prolia) targets a different step in the bone remodeling process than other medications.

Choosing among the options can be challenging as each class of medications is associated with a range side effects from bothersome to potentially disabling, and each has different levels of effectiveness in prevention of fractures.

Alendronate, ibandronate, risedronate, zoledronic acid, denosumab, teriparatide and raloxifene all showed strong evidence of preventing vertebral fractures in women with osteoporosis. Alendronate, risedronate, zoledronic acid, denosumab and teriparatide showed strong evidence or preventing non-vertebral fractures in women with osteoporosis.

Raloxifene did not prevent non-vertebral fractures, and there was less evidence to support ibandronate’s effectiveness against non-vertebral fractures relative to the other options. Recent studies have demonstrated that zoledronic acid has moderately strong evidence for prevention of vertebral fractures in men with osteoporosis. Most of the drugs tested were more effective than taking Vitamin D or calcium supplements to prevent fractures.

The bisphosphonates denosumab and teriparatide frequently caused mild upper-gastrointestinal symptoms. Raloxifene provoked hot flashes and thromboembolic events (blood clots). Teriparatide was associated with headache and increased blood calcium level. Zoledronic acid caused low blood calcium and influenza-like symptoms.

They found the risk of atypical hip fractures due to medication is much smaller than the risk of osteoporosis-related hip fractures in untreated women, making that risk-benefit data important in making informed treatment choices.

Denosumab also showed a moderate tendency toward causing infection. More seriously, atypical hip fractures at the end of the femur nearest the hip joint, and osteonecrosis of the jaw, a severe bone disease that affects the mandible and maxilla (jaw bones), have been associated with bisphosphonate use.

While the recent study confirmed this connection, it noted that the incidence of either side effect is low and can be reduced if the length of treatment with bisphosphonates is not prolonged. And since it is also true that the risk of atypical hip fractures is much smaller than the risk of osteoporosis-related hip fractures in untreated women, that risk-benefit data are important in making informed treatment choices.

There was varying evidence regarding recommendations for length of therapy, although some groups of patients can safely discontinue therapy at five years, while other high-risk patients may benefit from longer treatment. Efficacy of treatment and risk of subsequent fractures cannot be reliably predicted by following bone mineral density measurements.

One study showed that when women continued treatment with alendronate for ten years, their risk for non-vertebral fractures was not significantly different, but their risk for clinical recognized vertebral fractures was much lower than for women who stopped treatment after five years.

Patients who do not yet show serious bone loss will still want to review their risk factors for osteoporosis-related fractures with their healthcare providers.

The researchers conclude that there is good quality evidence to support the use of a variety of drugs for the treatment of osteoporosis for the prevention of vertebral and non-vertebral fractures.

They note that side effects vary among the drugs. There are too few studies to conclusively compare one medication to another directly, according to the researchers, but they report that the differences between the clinical efficacy of bisphosphonates, denosumab and teriparatide are likely to be modest. The research is published in Annals of Internal Medicine together with an editorial pointing out that the relative risks and benefits among those 75 and older were not part of the current meta-analysis.

Women and men with thinning bones should discuss various options with their medical providers before embarking on a course of therapy. Similarly, those who are experiencing unacceptable side effects may wish to discuss changing to a different type of medication.

Patients who do not yet show serious bone loss will still want to review their risk factors for osteoporosis-related fractures with their healthcare providers so they can identify those risks they may be able to decrease by medication and lifestyle choices.