In 2015, 11.9% of people with cystic fibrosis (CF) in the United States had osteopenia, 5.1% osteoporosis, and 0.3% experienced a fracture. Screening for CF-related bone disease starts in childhood, and dual energy x-ray absorptiometry (DXA) is the recommended method. It is unknown whether peripheral quantitative computed tomography (pQCT) can detect deficits earlier than DXA. This study compared pQCT and DXA scans in a group of pre-pubertal children with CF and healthy controls.
This was a cross-sectional study of children at Tanner stage 1. A pQCT scan of the radius at proximal and distal sites was performed plus a total body DXA scan. Serum C-reactive protein, interleukin-6 and tumor necrosis factor-alpha were also measured.
A total of 34 subjects completed the study; 14 with CF and 20 controls. At the distal radius, pQCT showed a lower total bone mineral density (BMD) Z-score for the CF group (P = 0.01 and P = 0.03 for 2 different reference databases) compared to controls. At the proximal site, the polar strength-strain index was lower in the CF group (P = 0.017). Finally, the total body BMD Z-score by DXA was lower in the CF group, although it did not meet the definition of reduced bone density (P = 0.004). Biomarkers of inflammation were not different.
In this group of pre-pubertal children with CF, measures of bone strength and density by both pQCT and DXA were reduced compared to healthy controls.
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This work was supported by the Children's University Medical Group, Arkansas Children's Hospital Research Institute intramural grant, http://www.archildrens.org/research/resources-for-researchers/intramural-grant-overview.
All relevant data are within the paper and its Supporting Information file.
S1 Table. Study data. https://doi.org/10.1371/journal.pone.0191013.s001 (XLSX)
O'Brien, Catherine E.; Com, Gulnur; Fowlkes, John L.; Tang, Xinyu; and James, Laura P., "Peripheral Quantitative Computed Tomography Detects Differences at the Radius in Prepubertal Children with Cystic Fibrosis Compared to Healthy Controls" (2018). Barnstable Brown Kentucky Diabetes and Obesity Center Faculty Publications. 3.