Osteoporosis and osteopenia in adults and adolescents with cystic fibrosis: prevalence and associated factors

• Published in: Thorax Vol. 55; no. 9; pp. 798 - 804
• Main Authors: Conway, S P, Morton, A M, Oldroyd, B, Truscott, J G, White, H, Smith, A H, Haigh, I
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Thoracic Society 01.09.2000; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Adolescent; Adult; Analysis of Variance; Biological and medical sciences; Body mass index; Bone Density - physiology; Bone Diseases, Metabolic - complications; Bone Diseases, Metabolic - epidemiology; Bone Diseases, Metabolic - physiopathology; corticosteroids; Cystic fibrosis; Cystic Fibrosis - complications; Cystic Fibrosis - physiopathology; Drug toxicity and drugs side effects treatment; Female; Forced Expiratory Volume - physiology; Humans; Male; Medical sciences; Original; osteopenia; osteoporosis; Osteoporosis - complications; Osteoporosis - epidemiology; Osteoporosis - physiopathology; Pharmacology. Drug treatments; Prevalence; Risk Factors; Statistics, Nonparametric; Studies; Teenagers; Toxicity: osteoarticular system; Vital Capacity - physiology; Vitamin D; United Kingdom > UK; Human; Corticosteroid; Respiratory disease; Toxicity; Diseases of the osteoarticular system; Metabolic diseases; Cystic fibrosis; Bone disease; Epidemiology; Genetic disease; Osteoporosis; Treatment; Adolescent; Digestive diseases; Adult; Osteopenia; Pancreatic disease
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thorax.55.9.798

BACKGROUND Patients with cystic fibrosis (CF) have many risk factors for reduced bone mineral density (BMD). The aim of this study was to determine the prevalence of osteoporosis and osteopenia in a large cross section of patients and to identify risk factors. METHODS All patients attending the regional centre were invited to participate in the study. Bone mineral density was measured at the lumbar spine, femoral neck, and for total body with a Lunar DPX-L densitometer. Multiple indices of disease severity were investigated, and liver and thyroid function, blood calcium, phosphate, 25-OH vitamin D, follicle stimulating and luteinising hormone, oestradiol, and testosterone levels were measured. Patients completed a four day prospective dietary diary. Exercise was assessed by a seven day activity recall questionnaire. Sexual development and treatment histories were obtained. The relationship between all these variables and BMD measurements was analysed. RESULTS Sixty six percent of 114 patients assessed had osteopenia or osteoporosis. The Shwachman-Kulczycki (SK) clinical score (higher score = less severe disease) correlated significantly with BMD at the lumbar spine and femoral neck, and with total body BMD (p<0.001). There was a predicted increase of 0.0032 g/cm2 in lumbar spine BMD for every unit increase in the SK score. Oral steroid use was significantly associated with reduced BMD at the lumbar spine (p = 0.017) and femoral neck (p = 0.027). CONCLUSIONS Osteopenia and osteoporosis are common findings in a heterogeneous population of adults with CF. Patients at most risk are those with severe disease and those who have used corticosteroids.