(From the May 2014 Issue of PediatricsOnline)
Bone density loss is common among adults and adolescents with cystic fibrosis, according to a new study by researchers at Nationwide Children’s Hospital. The findings illustrate a growing list of health issues faced by patients who are living longer with a disease that once resulted in death before elementary school.
A study of 103 patients with cystic fibrosis (CF) ages 16 to 53 found that 10 percent had osteoporosis and another 36 percent had osteopenia, a low bone density condition that often leads to osteoporosis. Males, patients with advanced disease and patients with severe malnutrition were more likely to have low bone density.
“As patients with cystic fibrosis are living longer, and quality of life with aging is an important issue, we need to closely monitor co-morbidities including osteopenia and osteoporosis,” says Shahid Sheikh, MD, a clinical researcher in Pulmonary Medicine at Nationwide Children’s and lead author of the study, published in a recent issue of the Journal of Bone and Mineral Metabolism.
CF affects about 1 in 2,500 Americans and is caused by a malfunction in the CFTR gene, which is responsible for transporting chloride and water across cell membranes, leading cells that line the passageways of the lungs, pancreas and other organs to produce mucus that is unusually thick and sticky. This mucus clogs the airways, leading to bacterial infections in the lungs, and blocks ducts in the pancreas, reducing insulin production and preventing digestive enzymes from reaching the intestines. One of the side effects of the disease is poor absorption of key nutrients, such as bone-fortifying calcium and vitamin D.
“As the disease progresses, bone mineral density loss increases, something that we suspected but are still learning more about,” Dr. Sheikh says.
Bone density loss is just one of many health issues that patients with cystic fibrosis are now dealing with — thanks in large part to better treatments and disease management programs that are allowing patients to live well into their 40s and 50s. As a result, clinicians and researchers are now learning more about the long-term effects of the disease. That information is leading pulmonologists such as Dr. Sheikh to share findings such as these with other medical specialists, including orthopedists, who may begin to see more CF patients in their waiting rooms.
“If an orthopedist is treating a fracture in a patient with cystic fibrosis, for example, they should be aware such patients are at an increased risk of having underlying low bone mineral density which may complicate healing,” says Dr. Sheikh, who also is an associate professor of clinical pediatrics at The Ohio State University College of Medicine. Some studies suggest that bone density loss can begin during adolescence in CF patients, Dr. Sheikh adds, so orthopedists should consider tracking bone density in their CF patients as early as age 12.
Dr. Sheikh and his colleagues are now looking into ways to improve bone density growth and retention among CF patients through a proposed clinical trial that would examine which therapies work best in this population.
Sheikh S, Gemma S, Patel A. Factors associated with low bone mineral density in patients with cystic fibrosis. Journal of Bone and Mineral Metabolism. 2014 Mar 16. [Epub ahead of print]