November 2011
This booklet contains general information about Paget's disease of bone. It describes what Paget's disease is, its causes, and treatment options. Highlights of current research are also included. If you have further questions, you may wish to discuss them with your health care provider.
Paget's disease of bone is a chronic disorder in which excessive breakdown and formation of bone tissue can lead to bone enlargement, weakening, and fractures, as well as pain and arthritis in the joints near the affected bones (see box "Bone Biology").
Unlike some other bone diseases, which affect all of the bones of the body, Paget’s disease typically affects just one or a few bones. The most commonly affected bones are those of the pelvis, skull, spine, and legs.
A less common form of Paget’s disease, called early-onset familial Paget’s disease of bone, shows up in a person’s teens or twenties. The early-onset form is similar to the classic form of the disorder except that it is more likely to affect the skull, spine, ribs, and small bones of the hands. It is also associated with hearing loss early in life.
Just because you have stopped growing taller, doesn’t mean your bones have stopped growing. Bone is living tissue that goes through a constant process of growth and renewal, called remodeling. This process, which is designed to supply the body with strong, healthy bone for a lifetime, occurs in two stages: bone resorption and bone formation. During resorption, cells called osteoclasts on the bones’ surface absorb old bone, creating small holes in the bone. During formation, the holes are systematically filled by bone-forming cells called osteoblasts.
When the process is working as it should, resorption and formation are balanced and responsive to the stresses placed on the bone. Much like muscles, bones that are worked grow stronger to meet the demands placed on them.
In Paget’s disease, however, this process is disrupted. Early in the disease process, bone resorption begins to outpace bone formation—old bone breaks down faster than new bone is built. Over time, your body overcompensates by speeding up bone formation. The new bone that is formed is abnormally large, weak, brittle, and prone to fractures.
For many people, Paget’s disease causes no symptoms. Some people have symptoms, but attribute them to other causes. Often people don’t realize they have the disease until they see a doctor about complications from it. Symptoms, when they occur, can include:
Symptoms get worse slowly, and the disease does not spread to other bones.
Beyond Bones: How Other Parts of the Body Can Be Affected by Paget’s Disease
Although Paget’s is a disease of bone, its complications can affect other body parts and functions, as well. Following are some of the possible complications.
Uncommon in people under age 40, Paget’s disease grows more common with age. The condition is more common in people of Anglo-Saxon descent in certain geographical areas including England, the United States, Australia, New Zealand, and Western Europe. It is not common in Scandinavia, China, Japan, or India.
Paget’s disease tends to occur in families. Research suggests that having a close relative with Paget’s disease makes you 7 to 10 times more likely to develop the disorder than someone without an affected relative.
Doctors do not know the exact cause of Paget’s disease, but the fact that the condition tends to run in families suggests that genes play a role. Several genes have been identified that appear to increase a person’s chances of having the disease.
However, genes alone are unlikely to cause the disorder. Though it has not been proven definitively, many doctors believe that something in the environment contributes to the development of Paget’s disease in people who are genetically predisposed. Some scientists are studying the possibility that a slow-acting virus may cause Paget’s disease.
A diagnosis of Paget’s disease is often made or confirmed by x ray. X rays of bone affected by Paget’s often show characteristic features. These may include a classical v-shaped pattern between healthy and diseased long bones, known as the blade of grass lesion, and patches of bone thickening, typically in the skull, referred to as the cotton wool pattern because of its poorly defined and fluffy appearance on x ray.
Other tests used in the diagnosis of Paget’s disease are:
Alkaline phosphatase blood test. This test is used to measure levels of serum alkaline phosphatase (SAP), a type of enzyme made by bone cells and overproduced by bones affected by Paget’s disease. Although there are several possible causes for a mild elevation in SAP, a level that is greater than twice the usual level strongly suggests Paget’s.
Bone scan. A bone scan is a test in which a small amount of radioactive dye is injected into a vein in the arm. The dye circulates through the bloodstream and collects in areas where there is increased blood flow and activity of bone-forming cells characteristic of Paget’s disease. A special camera scans the bones, detecting areas where the dye has collected. If a scan suggests Paget’s disease, x rays may be used to confirm the diagnosis. Bone scans may also be used to determine the extent and activity of the disorder.
Bone biopsy. In rare cases, doctors remove a small sample of bone (called a biopsy) and examine it under a microscope. Biopsies may be performed if x rays fail to confirm or refute a Paget’s diagnosis. Biopsies may also be used to rule out bone cancer.
Paget’s disease is often diagnosed and treated by endocrinologists or rheumatologists. Endocrinologists are doctors who specialize in diagnosing and treating hormonal conditions. Rheumatologists are doctors who specialize in disorders of the joints, connective tissues, and muscles.
Other doctors may treat different specific symptoms or complications of Paget’s disease. These include:
The goals of Paget’s disease treatment are to control excessive bone breakdown and formation, reduce the risk of complications, and ease bone and joint pain. In more severe, advanced cases it may also involve repairing fractures, correcting bone deformity, and replacing joints damaged by the disease. Treatment includes the following:
Several types of medications may be used in Paget’s disease treatment. They include:
Several over-the-counter (OTC) medications may help ease the pain associated with Paget’s disease. These include aspirin, acetaminophen, ibuprofen,1 and naproxen. For more severe pain that does not respond to OTC medications, doctors may recommend a prescription pain reliever.
1 Warning: NSAIDs can cause stomach irritation or, less often, they can affect kidney function. The longer a person uses NSAIDs, the more likely he or she is to have side effects, ranging from mild to serious. Many other drugs cannot be taken when a patient is being treated with NSAIDs, because NSAIDs alter the way the body uses or eliminates these other drugs. Check with your health care provider or pharmacist before you take NSAIDs. Also, NSAIDs sometimes are associated with serious gastrointestinal problems, including ulcers, bleeding, and perforation of the stomach or intestine. People over age 65 and those with any history of ulcers or gastrointestinal bleeding should use NSAIDs with caution.
Although medications can often regulate bone growth and minimize complications, surgery may be necessary to correct problems that result from irregular bone growth, including:
Aside from following your doctor’s prescribed treatment, there are things you can do to be healthier and help reduce risk of complications. Here are some to do now:
Recommended Calcium and Vitamin D Intakes
Life-stage group | Calcium mg/day | Vitamin D (IU/day) |
---|---|---|
Infants 0 to 6 months | 200 | 400 |
Infants 6 to 12 months | 260 | 400 |
1 to 3 years old | 700 | 600 |
4 to 8 years old | 1,000 | 600 |
9 to 13 years old | 1,300 | 600 |
14 to 18 years old | 1,300 | 600 |
19 to 30 years old | 1,000 | 600 |
31 to 50 years old | 1,000 | 600 |
51- to 70-year-old males | 1,000 | 600 |
51- to 70-year-old females | 1,200 | 600 |
>70 years old | 1,200 | 800 |
14 to 18 years old, pregnant/lactating | 1,300 | 600 |
19 to 50 years old, pregnant/lactating | 1,000 | 600 |
Definitions: mg = milligrams; IU = International Units
Source: Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, 2010.
Paget’s disease is rarely fatal. For most people with the disorder, the prognosis is good, particularly if they begin treatment before major changes have occurred in the affected bones. Because early diagnosis and treatment is important to minimize complications, doctors may recommend that family members of people with Paget’s disease (who face an increased risk of the disorder themselves) have an alkaline phosphatase blood test every 2 to 3 years beginning around age 40. If the level is elevated, suggesting possible Paget’s disease, bone scans or x rays may be used to verify the diagnosis, so that treatment can begin early in the disease process. Although treatment is effective at controlling symptoms and minimizing the risk of complications, it cannot cure Paget’s disease. A small percentage of people with Paget’s disease—perhaps less than 1 in 1,000—develop a rare type of bone cancer called osteosarcoma, which may be treated with surgery, radiation, and/or chemotherapy.
Researchers are working to identify the most effective and safe treatments for Paget’s disease and looking for new targets for drug therapy. Researchers are also beginning to target factors that link bone resorption (or breakdown) and bone formation, two processes that must work in concert to provide us with healthy bones (see box “Bone Biology”). In Paget’s disease, the processes of bone resorption and formation remain coupled, but both proceed at abnormally high rates, producing excessive bone of poor quality. Scientists are also continuing to examine the causes and mechanisms of Paget’s disease, including the genes that are involved. Identifying and better understanding the genes involved in the disease could help doctors predict who may be at risk for it and could lead to the development of specific therapies not only to slow damage, but perhaps to stop and could even reverse the damage. The role of environmental factors—such as viruses—in the development of Paget’s is just beginning to be clarified. Researchers are exploring whether such factors contribute to the development of the disease in people who are genetically predisposed.
2 AMS Circle
Bethesda, MD 20892-3676
Phone: 202-223-0344
Toll Free: 800-624-BONE (2663)
TTY: 202-466-4315
Fax: 202-293-2356
Email: NIHBoneInfo@mail.nih.gov
Website: http://www.bones.nih.gov
Website: http://www.aaos.org
Website: http://www.rheumatology.org
Website: http://www.paget.org
Alkaline phosphatase blood test. A test that measures blood levels of an enzyme made by bone cells and overproduced by bones affected by Paget’s disease. A highly elevated level of this enzyme may indicate a diagnosis of the disorder.
Bisphosphonates. A type of medication that works to control excessive bone breakdown and formation that occurs in Paget’s disease. Bisphosphonates are commonly used medications to treat Paget’s disease.
Blade of grass lesion. A v-shaped pattern between healthy and diseased long bones that may show up on x rays in people with Paget’s disease. The presence of the pattern is useful in diagnosing the disorder.
Bone biopsy. A test in which a small sample of bone is removed and examined under a microscope. Biopsies are sometimes used to confirm a diagnosis of Paget’s disease or to rule out bone cancer.
Bone scan. A test in which a small amount of radioactive dye is injected into a vein in the arm and allowed to circulate through the bloodstream. A special camera is then used to scan the bones and detect areas of increased blood flow or bone-forming cells. Bone scans may be used to diagnose Paget’s disease and to determine its extent and activity.
Calcitonin. A medication derived from salmon. It is similar to a hormone made by the thyroid gland that regulates blood 18 levels of calcium and phosphate and promotes the formation of new bone. It is sometimes used in Paget’s disease treatment.
Cotton wool appearance. A fluffy, poorly defined patch on an x ray, typically of the skull, due to bone thickening. Its appearance is useful in the diagnosis of Paget’s disease.
Endocrinologist. A doctor who specializes in the diagnosis and treatment of conditions involving hormones and metabolism. Endocrinologists commonly treat Paget’s disease.
Heart failure. A condition in which the heart is unable to deliver enough blood to meet the body’s needs. In people with extensive Paget’s disease, the heart may have to work harder to pump blood to affected areas of the body. If the heart is already damaged, the increased workload may lead to heart failure.
Osteoarthritis. A joint disease that occurs when the cartilage that cushions the ends of the bones where they meet to form joints wears away, leading to pain, stiffness, and the formation of bony outgrowths called spurs. Osteoarthritis is a common long-term complication of Paget’s disease.
Osteoblasts. Bone-forming cells. In Paget’s disease, overactivity of osteoblasts leads to bone that is abnormally large, weak, and brittle.
Osteoclasts. Cells on the bones’ surfaces that absorb old bone, creating small holes in the bone to be filled by bone-forming cells called osteoblasts.
Orthopaedic surgeon. A doctor who specializes in the diagnosis, treatment, and prevention of injuries, disorders, and diseases of the musculoskeletal system, which includes bones, joints, ligaments, muscles, nerves, and tendons.
Osteosarcoma. A rare type of bone cancer that can occur as a complication of Paget’s disease. It is estimated to affect less than 1 in 1,000 patients with Paget’s disease.
Otolaryngologists. Doctors who specialize in the diagnosis and treatment of conditions of the ear, nose, and throat. People with Paget’s disease may see an otolaryngologist for some of the complications of their disease.
Rheumatologists. Doctors who specialize in diagnosing and treating disorders of the joints and muscles.
X ray. A test in which an x-ray beam is passed through the body to create a two-dimensional picture of the bones. X rays are used to diagnose Paget’s disease.
The NIAMS gratefully acknowledges the assistance of the following individuals in the preparation and review this booklet: Kenneth W. Lyles, M.D., Professor of Medicine, Duke University and VA Medical Centers, Durham, NC; G. David Roodman, M.D., Ph.D., Professor of Medicine and Vice Chair for Research, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA; Charlene Waldman, Executive Director, The Paget Foundation, New York; Joan A. McGowan, Ph.D., Director, Division of Musculoskeletal Diseases, NIAMS; and William J. Sharrock, Ph.D., Director, Integrated Physiology and Genetics of Bone Program, Division of Musculoskeletal Diseases, NIAMS.
This publication may contain information about medications used to treat the health condition discussed here. When this publication was produced, we included the most up-to-date (accurate) information available. Occasionally, new information on medication is released.
For updates and for any questions about any medications you are taking, please contact:
Website: http://www.fda.gov
Toll free: 888–INFO–FDA (888–463–6332)
For updates and questions about statistics, please contact:
Website: http://www.cdc.gov/nchs
Toll free: 800–232–4636
NIH Publication No. 10-7670
2 AMS Circle
Bethesda, MD 20892-3676
Phone: 202-223-0344
Toll Free: 800-624-BONE (2663)
TTY: 202-466-4315
Fax: 202-293-2356
Email: NIHBoneInfo@mail.nih.gov
Website: http://www.bones.nih.gov
The NIH Osteoporosis and Related Bone Diseases ~ National Resource Center provides patients, health professionals, and the public with an important link to resources and information on metabolic bone diseases. The mission of NIH ORBD~NRC is to expand awareness and enhance knowledge and understanding of the prevention, early detection, and treatment of these diseases as well as strategies for coping with them.
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