Data from: The effects of ivacaftor on bone density and microarchitecture in children and adults with cystic fibrosis

Context: Cystic fibrosis transmembrane conductance (CFTR) dysfunction may
play a role in CF-related bone disease (CFBD). Ivacaftor is a CFTR
potentiator effective in improving pulmonary and nutritional outcomes in
patients with the G551D-CFTR mutation. The effects of ivacaftor on bone
health are unknown. Objective: To determine the impact of ivacaftor on
bone density and microarchitecture in children and adults with CF. Design:
Prospective observational multiple cohort study. Setting: Outpatient
clinical research center within a tertiary academic medical center.
Patients or Other Participants: Three cohorts of age-, race-, and
gender-matched subjects were enrolled: 26 subjects (15 adults and 11
children) with CF and the G551D-CFTR mutation who were planning to start
or had started treatment with ivacaftor within three months (Ivacaftor
cohort); 26 subjects with CF were not treated with ivacaftor (CF Control
cohort); and 26 healthy volunteers. Interventions: All treatments,
including ivacaftor, were managed by the subjects’ pulmonologists. Main
Outcome Measures: Bone microarchitecture by high resolution peripheral
quantitative computed tomography (HR-pQCT), areal bone mineral density
(aBMD) by dual-energy X-ray absorptiometry (DXA) and bone turnover markers
at baseline, 1, and 2 years. Results:  Cortical volume, area, and
porosity at the radius and tibia increased significantly in adults in the
Ivacaftor cohort. No significant differences were observed in changes in
aBMD, trabecular microarchitecture, or estimated bone strength in adults
or in any outcome measures in children. Conclusions: Treatment with
ivacaftor was associated with increases in cortical microarchitecture in
adults with CF. Further studies are needed to understand the implications
of these findings.