Impact of lung inflammation on bone metabolism in adolescents with cystic fibrosis.

Deficits in bone mineral density resulting in premature osteopenia and osteoporosis have been documented in cystic fibrosis patients for over 20 years. A high incidence of fractures and kyphosis in the continually increasing adult patient population and in post-lung transplant patients has highlighted the problems associated with poor bone health.The aetiology of osteoporosis in CF is multifactorial but centres on an uncoupling in the normal balance between bone formation and resorption. Delayed puberty, malabsorption and reduced weight-bearing exercise can result in inadequate bone mineral accretion in childhood and adolescence. Corticosteroid use and pro-inflammatory cytokines associated with infective respiratory exacerbations can accelerate bone loss. Dual energy X-ray absorptiometry is the most commonly available technique to measure bone mineral density. All patients should be scanned at least every 2 years from adolescence. The treatment of established disease with bisphosphonates shows encouraging early results.