Bone-Related Complications Emerge as Cystic Fibrosis Patients Age

Medical advances related to the diagnosis and management of cystic fibrosis (CF) have allowed CF patients to live considerably longer. But with that greater life expectancy, new complications have emerged.

Researchers at the University of Alabama at Birmingham and the Birmingham Veterans Administration Medical Center took a focused look at the changing face of CF in a review published in Current Opinion in Endocrinology, Diabetes and Obesity. The basic manifestations of this life-limiting disorder reflect defective chloride channel functioning of the CF transmembrane conductance regulator (CFTR) protein that controls pulmonary mucous. Since CF patients experience difficulties with mucous blockage and obstruction of the lungs, chronic bacterial lung infections plague this population.

However, the authors said endocrine disorders are now the leading complications in light of CF patients’ increased survival times, and CF-related diabetes (CFRD) and CF-related bone disease (CFBD) are the most common. In fact, 19% of CF patients have CFRD — a proportion increases with age. In addition, CFBD presently affects at least 11% of CF patients, and 57% of late-stage CF patients have osteoporosis.

The researchers advocated that clinicians screen all CF patients for CFBD at or before age 18, as well as monitor known contributors to the disease, such as vitamin D and calcium deficiency. Adults with a Z-score of less than —2 by dual-energy X-ray absorptiometry (DXA) should be offered bisphosphonate therapy. Other interventions like teriparitide, hormonal replacement, and denosumab are promising, but they have not been studied in the CF population.

According to the authors, data on new interventions will become increasingly important as endocrinologists find more bone complications in the CF population. In the meantime, the Cystic Fibrosis Foundation has published a consensus statement describing the best practices for managing bone-related endocrine disorders in CF patients.