Controlled longitudinal study of bone mass accrual in children and adolescents with cystic fibrosis
- H M Buntain1,2,
- P J Schluter3,
- S C Bell4,
- R M Greer2,
- J C H Wong5,
- J Batch6,
- P Lewindon7,
- C E Wainwright1
- 1Department of Respiratory Medicine, Royal Children’s Hospital, Herston, Brisbane, Australia
- 2Department of Paediatrics and Child Health, University of Queensland, Herston, Queensland, Australia
- 3Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
- 4Adult Cystic Fibrosis Unit and the Department of Medicine, University of Queensland, The Prince Charles Hospital, Chermside, Queensland, Australia
- 5Department of Nuclear Medicine and Bone Densitometry, Royal Brisbane and Women’s Hospital, Herston, Queensland, Australia
- 6Department of Endocrinology, Royal Children’s Hospital, Herston, Brisbane, Australia
- 7Department of Gastroenterology and Hepatology, Royal Children’s Hospital, Herston, Brisbane, Australia
- Correspondence to:
Dr H Buntain
Department of Respiratory Medicine, Royal Children’s Hospital, Herston, QLD 4029, Australia;
- Received 14 May 2005
- Accepted 21 November 2005
- Published Online First 29 December 2005
Background: A study was undertaken to observe the gains in bone mass in children and adolescents with cystic fibrosis (CF) over 24 months and to examine the relationship between areal bone mineral density (aBMD) and associated clinical parameters including physical activity, nutrition, and 25-hydroxyvitamin D (25OHD).
Methods: Areal BMD of the total body (TB), lumbar spine (LS), and total femoral neck (FNt) were repeatedly measured in 85 subjects aged 5–18 years with CF and 100 age and sex matched controls over 2 years. At each visit anthropometric variables, nutritional parameters, pubertal status, disease severity, physical activity, dietary calcium, caloric intake, and serum 25OHD were assessed and related to aBMD.
Results: After adjusting for age, sex, and height Z-score, gains in LS aBMD in children (5–10 years) and TB and FNt aBMD in adolescents (11–18 years) with CF were significantly less than in controls. Lean tissue mass was significantly associated with TB and LS aBMD gains in children and adolescents and explained a significant proportion of the aBMD deficit observed. Lung function parameters were significantly associated with aBMD gains in adolescents with CF.
Conclusions: Inadequate bone mass accrual during childhood and adolescence contributes to the low bone mass observed in adults with CF. Accounting for the height discrepancy which is frequently observed in those with CF, in addition to age and sex, is important when assessing low bone mass in children and adolescents with CF. To optimise an individual’s potential to acquire maximal bone mass, it is necessary to maximise nutritional status and limit the progression of chronic suppurative lung disease.
- aBMD, areal bone mineral density
- BMC, bone mineral content
- CF, cystic fibrosis
- FEV1, forced expiratory volume in 1 second
- FNt, total femoral neck
- FVC, forced vital capacity
- LS, lumbar spine
- LTM, lean tissue mass
- 25OHD, 25-hydroxyvitamin D
- 1, 25(OH)2D, 1,25-dihydroxyvitamin D
- TB, total body
Published Online First 29 December 2005
The study was supported by Cystic Fibrosis Research Australia Pty Ltd, the Royal Children’s Hospital Foundation – Working Wonders, and an Allen and Hanbury paediatric career development grant.
None of the authors has any competing interests with regard to this publication. Specifically, in relation to this study, none of the authors has in the last five years (1) accepted reimbursement or a fee that may in any way gain or lose financially from the results, (2) been employed by an organisation that may in any way gain or lose financially from the results, (3) hold any stocks or shares in an organisation that may in any way gain or lose financially from the results, (4) acted as an expert witness on the subject, or (5) any other competing financial interests.