Patients with cystic fibrosis (CF) have low bone mineral density (BMD). The clinical relevance of this is not clearly established. The aim of this study was to determine the prevalence of low BMD and vertebral deformities in CF adults with varied disease severity. One hundred and seven patients (58 men) aged 18-60 years underwent dual-energy X-ray absorptiometry scanning of the lumbar spine and hip, radiology of the spine and biochemical studies. Thirty-eight percent had a Z-score of < -1, with 13% having Z-scores < -2. Seventeen percent had evidence of vertebral deformity on radiography, mostly in the thoracic spine. Thirty-five percent reported past fractures, of which 9% were rib fractures. Percent predicted forced expiratory volume in 1 second (FEV1) and the amount of daily physical activity were positively related to BMD. The number of intravenous antibiotic courses in the previous 5 years was negatively related to BMD. Patients with a history of rib fracture and CF-related diabetes had significantly lower femoral neck BMD (p < 0.02). The median serum 25-hydroxyvitamin D was 28 nmol/l, with 36% of patients having levels below 25 nmol/l despite vitamin D supplementation. Forty-four percent had raised levels of urinary pyridinium crosslinks (NTx). In conclusion, fragility fractures and hypovitaminosis D occur commonly in adult patients with CF. Low BMD occurs in patients with more severe disease and significantly relates to FEV1, infective exacerbations and daily energy expended in physical activity.

In different countries either one or several airway clearance regimens are used. This study provides evidence in support of current practices.

The use of HbA1c ≥ 5.8%(40 mmol/mol) is an effective tool for CFRD screening and reduced the need for an OGTT by 50.7%.

Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with CF. No significant association was found.