Dual energy X-ray absorptiometry diagnostic discordance between Z scores and T scores in a young Iranian population

Heidari, B., Khashayar, P., Rezaei Homami, M., Pajouhi, A., Soltani, A. and Larijani, B. (2014) Dual energy X-ray absorptiometry diagnostic discordance between Z scores and T scores in a young Iranian population. Medical Journal of the Islamic Republic of Iran, 28, 151. (PMID:25695009) (PMCID:PMC4322344)

Abstract

Background: Dual-energy X-ray Absorptiometry (DXA) is considered the gold standard for non-invasive measurement of bone mass. T-scores and Z-scores are used to present the results of bone mass. The present study was designed to evaluate the discordance between T-scores and Z-scores calculated at a same level and its relation with age, gender and body mass index (BMI) in a representative sample of normal population. Methods: This cross-sectional study was conducted as a part of a comprehensive survey, Iranian Multicenter Osteoporosis Study (IMOS), designed to assess bone health among healthy adults. Each individual underwent both L1–L4 antero-posterior lumbar spine and hip DXA scan. The difference between the T- and Z-scores measured at each of the four skeletal sites was then calculated. Results: A -1.21 to 1.21 point difference was noted in the Z- and T- scores measured at each site. While the difference between the T- and Z-scores was less than 0.5 SD in most of the cases, the difference was higher than 1 SD in about 5% of the subjects. Conclusion: Standardization of Z-score definition and calculation techniques as well as developing an ethnicity-matched reference population is needed to improve the reliability of DXA-generated Z-scores.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Rezaeihemami, Dr Mohsen
• Authors: Heidari, B., Khashayar, P., Rezaei Homami, M., Pajouhi, A., Soltani, A., and Larijani, B.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Health Economics and Health Technology Assessment
• Journal Name: Medical Journal of the Islamic Republic of Iran
• Publisher: Tehran University of Medical Sciences
• ISSN: 1016-1430
• ISSN (Online): 2251-6840
• Copyright Holders: Copyright © 2014 The Authors
• First Published: First published in Medical Journal of the Islamic Republic of Iran 28: 151
• Publisher Policy: Reproduced under a Creative Commons License