Revised reference curves of bone mineral density according to age and sex for Iranian children and adolescents
Bone health evaluation in children requires an appropriate reference database. We have shown higher curves for spine aBMD in Iranian subjects than Americans, but lower curves for femoral neck and total body. These results can be used as reference values to assist Iranian clinicians in interpreting and monitoring bone densitometry results.
Bone health evaluation requires an appropriate reference database that can identify the bone deficit according to age, sex, puberty, and race. The aim of this study was to determine bone mineral density Z-scores in Iranian children and adolescents and their comparability with other reference data.
A sample of 476 healthy children and adolescents, aged 9–18 years, from Kawar (an urban community, 50 km east of Shiraz, Iran) was selected and bone mineral measurements of the lumbar spine, femoral neck, and total body (less head) were done. Sex-specific height-for-age, weight-for-age, and BMI-for-age Z-scores, as well as bone mineral density Z-scores, were calculated.
Extended reference curves for bone mineral content (BMC) and areal bone mineral density (aBMD) of the total body less head, lumbar spine, and femoral neck, for ages 9–18 years were constructed relative to sex and age. We found that median, − 2SD, and + 2SD curves for the lumbar spine aBMD were higher in Iranian subjects than in the American participants, but the curves of the femoral neck and total body were lower. Also, we showed that subjects with a lower height-for-age Z-score had a lower BMC and aBMD Z-score in the lumbar spine, femoral neck, and total body (p < 0.001).
Relevant differences in bone mineral density and its curves exist between Iranian children and adolescents and other databases, revealing a significant potential for misdiagnosis. However, our results can be used to provide reference databases to assist clinicians in interpreting, assessing, and monitoring bone densitometry.
KeywordsBone mass Z-score aBMD
The authors thank Shiraz University of Medical Sciences, Shiraz, Iran, and the Center for Development of Clinical Research of Nemazee Hospital and thank Dr. Nasrin Shokrpour for editorial assistance.
Compliance with ethical standards
Conflict of interest
- 4.Kuczmarski RJ, Ogden CL, Grummer-Strawn LM, Flegal KM, Guo SS, Wei R et al (2000) CDC growth charts: United States. Adv Data 8(314):1–27Google Scholar
- 5.Bishop N, Arundel P, Clark E, Dimitri P, Farr J, Jones G, Makitie O, Munns CF, Shaw N, International Society of Clinical Densitometry (2014) Fracture prediction and the definition of osteoporosis in children and adolescents: the ISCD 2013 Pediatric Official Positions. J Clin Densitom 17(2):275–280CrossRefGoogle Scholar
- 6.Kelly T, Specker B, Binkley T, Zemel B, Leonard M, Kalkwarf H et al (2005) Pediatric BMD reference database for US white children. Children’s Bone health Abstract, Sorrento, Italy. Bone 36(suppl 1):S5–S110Google Scholar
- 9.Ma J, Siminoski K, Alos N, Halton J, Ho J, Lentle B, Matzinger M, Shenouda N, Atkinson S, Barr R, Cabral DA, Couch R, Cummings EA, Fernandez CV, Grant RM, Rodd C, Sbrocchi AM, Scharke M, Rauch F, Ward LM, Canadian STOPP Consortium (2015) The choice of normative pediatric reference database changes spine bone mineral density Z-scores but not the relationship between bone mineral density and prevalent vertebral fractures. J Clin Endocrinol Metab 100(3):1018–1027CrossRefGoogle Scholar
- 11.Cole TJ (1998) Fitting smoothed centile curves to reference data. J R Stat Soc Series A (Statistics in Society) 151(3):385–418Google Scholar
- 13.Zemel BS, Kalkwarf HJ, Gilsanz V, Lappe JM, Oberfield S, Shepherd JA, Frederick MM, Huang X, Lu M, Mahboubi S, Hangartner T, Winer KK (2011) Revised reference curves for bone mineral content and areal bone mineral density according to age and sex for black and non-black children: results of the bone mineral density in childhood study. J Clin Endocrinol Metab 96(10):3160–3169CrossRefGoogle Scholar
- 16.Kalkwarf HJ, Zemel BS, Gilsanz V, Lappe JM, Horlick M, Oberfield S, Mahboubi S, Fan B, Frederick MM, Winer K, Shepherd JA (2007) The bone mineral density in childhood study: bone mineral content and density according to age, sex, and race. J Clin Endocrinol Metab 92(6):2087–2099CrossRefGoogle Scholar