BONE-MINERAL DENSITY AND BODY-COMPOSITION IN ADULT PATIENTS WITH CYSTIC-FIBROSIS

Background-Cystic fibrosis is a multisystem disease characterised by c hronic pulmonary sepsis and malnutrition. To ascertain whether osteopo rosis is a feature of cystic fibrosis in adult patients, total body an d regional bone mineral density (BMD) was measured in a group of eight men and eight women aged 17-42 years. Methods-Total body and regional BMD (lumbar spine L2-L4, femoral neck, trochanteric, and Ward's trian gle), as well as total body fat and lean mass, were measured by dual e nergy x ray absorptiometry. A range of biochemical, lifestyle, and ant hropometric variables was also assessed. Results-Patients with cystic fibrosis had significantly reduced bone density at all sites compared with normal young adults. The mean reductions ranged from 7% at Ward's triangle to 13% at the trochanter. Body mass index (BMI) was positive ly correlated with BMD at four sites and disease severity negatively c orrelated with BMD at two sites. Other biochemical and anthropometric variables were not predictive of bone density. Total body fat mass was reduced by 30% compared with normal young adults. Conclusions-Bone de nsity is decreased in adult patients with cystic fibrosis and BMI and disease severity are independent predictors of bone density.