Paget’s disease is a relatively common disorder of the bone that has no symptoms early in the process but can progress to pain and fractures in later stages. It is more common in certain geographical areas than others, and may be familial in nature. First named after it was described by Dr. James Paget in 1877, it can affect bone in a localized manner or be present in many long bones.
Bone turnover (or bone metabolism) is a lifelong process in which mature bone tissue is removed from the skeleton (a process called bone resorption) and new bone tissue is formed (a process called ossification or new bone formation). During the first year of life, nearly 100 percent of the skeleton is replaced, while in adults, remodeling is about 10 percent per year.
Paget’s is a progressive disease in which bone in the skeleton is resorbed and then misshapenly remodeled. Think of it as a house which is disassembled and then put together again haphazardly. The new structure is weaker and the foundation compromised.
Paget’s sufferers are susceptible to fractures and pain in the involved bones and the process is vascular in formation, meaning cardiac output can be compromised at older ages from the increased blood flow to the areas at risk. Paget’s is estimated to occur in up to 3 percent of people age 55 and older and up to 8 percent of people in Europe, Canada and Australia/New Zealand. It is rare in Japan, Scandinavia, Russia and Africa for unknown reasons. Men are affected more than women.
Most people are diagnosed incidentally before there is pain and obvious deformity of the skeletal long bones. Routine blood testing, done for most doctors’ exams and insurance blood workups, shows a markedly elevated alkaline phosphatase level. X-rays of affected bones (usually done for other reasons) demonstrate as an incidental finding clear changes caused by Paget’s.
The bone density is increased but deformed in appearance and there is thickening of the long bones and skull in many cases. Headaches and hearing loss can occur, depending on which bones are involved and to what degree. In addition, there is a higher incidence of kidney stone formation from the increased calcium in the bloodstream and, in late cases, heart failure can occur when the body tries to keep up with the increased demand from bone hyperactivity.
While many early or slowly progressive cases of Paget’s don’t need treatment other than pain relief or anti-inflammatory medication, advanced cases are treated with medication that slows bone turnover. Etidronate was the first drug used to treat Paget’s back in 1977 and is still in widespread use today. Newer drugs in this biphosphonate family, such as risedonate and tiludronate, have fewer side effects and are more frequently used.
Medications are often given intravenously and one (zoledronic acid) may have to be used only once to have an effect for several years. They reduce bone turnover and keep the disease in remission but generally do not correct already existing deformities.
Most cases are considered on a combination of age at onset, degree of involvement and whether other body organs (heart, kidneys) are involved. Most mild to moderate cases, especially over the age of 60, can be considered at standard rates. Rated cases involve higher bone turnover and more involved medication needs. Cases where repeated fractures or heart failure are involved have the poorest outcome.
Robert Goldstone, MD, FACE, FLMI
Goldstone, board certified internist and endocrinologist, is vice president and chief medical officer for Pacific Life and Pacific Life and Annuity. He has extensive brokerage and life insurance experience, having been medical director at both MetLife Brokerage and Transamerica Occidental Life. Goldstone is board certified in insurance medicine and the inaugural recipient of the W. John Elder Award for Insurance Medicine Journalism Excellence. He was also honored as a fellow of the prestigious American College of Endocrinology and has written monthly for Broker World since 1990. Goldstone can be reached by telephone at 949-420-8390. Email: firstname.lastname@example.org.