In addition to raising the risk of fracture during childhood, the researchers also found that childhood-onset arthritis potentially heightens fracture risk after age 45.
A research team led by pediatric rheumatologist Jon M. Burnham, M.D., of The Children's Hospital of Philadelphia and the University of Pennsylvania, analyzed the medical records of 1,959 patients in the United Kingdom who first experienced arthritis between ages one and 19. The researchers compared those patients to a larger control group of 207,000 patients in a primary care database.
The study appeared online in the Annals of the Rheumatic Diseases on April 21. It was the first research to examine, in a population-based study, the risk of fractures in childhood arthritis patients.
Juvenile idiopathic arthritis (JIA), also called juvenile rheumatoid arthritis, is the most common pediatric rheumatic disease, affecting approximately one in 1,000 U.S. children. It was already known that low bone mass occurs in patients with JIA, because of risk factors such as chronic inflammation, delayed puberty, malnutrition, weakness, inactivity and treatment with steroid medications.
"The goal of this study was to determine if the bone abnormalities seen in JIA are clinically significant, resulting in higher fracture rates, and that is exactly what we found," said Dr. Burnham. "The low bone mass in JIA is associated with skeletal fragility, and causes both short-term and long-term health problems. Someone who fails to attain peak bone mass during adolescence and young adulthood is more vulnerable to fractures in later life, when bone mass inexorably declines."