This article is more than 5 years old. Information may no longer be current.
Impaired bone accrual more likely in children with cystic fibrosis
Click Here to Manage Email Alerts
Children and adolescents with cystic fibrosis are more likely to exhibit impaired bone accrual with more severe disease, even when linear growth is not affected, according to findings from a retrospective, longitudinal study.
“Bone acquisition is impaired in the sickest children with cystic fibrosis, as judged by their nutritional status and lung function,” Sonakshi Sharma, MBBS, FRACP, an endocrinologist with Greenlane Clinical Centre in Auckland, New Zealand, told Endocrine Today. “Measures to optimize and maintain nutritional status and lung function (especially during adolescence, which is a critical phase for bone accrual) can help reduce the prevalence of low bone mineral density in young people with cystic fibrosis.”
Sharma and colleagues analyzed data from 60 children with confirmed cystic fibrosis (24 girls; mean age at first scan, 12.6 years) who underwent at least one DXA scan, measuring lumbar spine BMD (L1-L4), BMI, and forced expiratory volume in 1 second (FEV1) z score; 40 children underwent sequential spinal DXA scans at a mean age of 16 years. Researchers used change in L1-L4 z score over time as a measure of bone accrual, and BMI as a measure of nutritional status; lung function (measured as FEV1) and BMI data were analyzed for change over time. Primary outcome was correlations between lumbar spine BMD, BMI and FEV1 z scores.
Mean BMI and BMD z scores were correlated at the baseline DXA scan (r = 0.68; P < .0001), suggesting that nutritional status is a major determinant of BMD, the researchers wrote. In the sequential DXA scan performed an average of 4 years later, there was no change in mean height z score (–0.49 to –0.27; P = .03) or mean L1-L4 z score (–0.94 to –1.13; P = .13), indicating normal linear growth, according to the researchers.
Changes in BMI and BMD z score were positively correlated (r = 0.5; P = .001), indicating that patients failing to gain weight appropriately with growth were also failing to acquire bone normally. Change in FEV1 z score was correlated with both change in BMD z score (r = 0.63; P < .0001), and change in BMI z score (r = 0.36; P = .02).
The researchers noted that pubertal status and the prevalence of hypogonadism were not known, and that quantitative CT was not used in this study to assess volumetric density in the cohort. Sharma said studies utilizing quantitative CT in this population will provide a better indication of bone density in growing children vs. areal BMD. – by Regina Schaffer
For more information:
Sonakshi Sharma, MBBS, FRACP, can be reached at the department of medicine at Taranaki Base Hospital, 23 David St., Westown, New Plymouth, New Zealand; email: sonakshi_sharma@hotmail.com.
Disclosure: The researchers report no relevant financial disclosures.
Click Here to Manage Email Alerts