Cystic fibrosis (CF) affects an estimated 30,000 people in the United States and is caused by
a mutation in the gene encoding a protein called CF transmembrane regulator (CFTR). The
hallmarks of CF are recurrent pulmonary exacerbations and declining pulmonary function.
However, there are other problems in CF that affect both health and quality of life. These
include CF related diabetes, liver disease, and bone disease. The median age of survival for
patients with CF has been increasing steadily and is currently more than 37 years. With this
improvement in life expectancy, it has become increasingly important to address the long-term
complications of CF.
Currently, patients with CF are evaluated annually for bone disease with dual X-ray
absorptiometry (DXA), and screening usually starts at age 12. However, this may not be
sufficient to detect early bone changes that may impact fracture risk. Furthermore, bone
disease in children may manifest earlier than adolescence, which would suggest that screening
should start at an earlier age in these vulnerable patients. The following study is therefore
proposed to examine the potential role of peripheral quantitative computed tomography (pQCT)
as a screening approach for bone disease in children with CF. The investigators expect to
find bone problems by pQCT but not DXA.