Clinical research Avoiding the under-diagnosis of low bone mineral density in Egyptian children with chronic medical conditions affecting bone health Nagwa Abdallah Ismail Submitted: 20 September 2010 Accepted: 7 December 2010 Arch Med Sci 2011; 7, 4: 700-705 DOI: 10.5114/aoms.2011.24142 Copyright © 2011 Termedia & Banach A b s t r a c t Paediatrics Department, National Research Centre, Cairo, Egypt Introduction: The International Society for Clinical Densitometry recommended that the lumbar spine and total body less head (TBLH) are the most accurate and reproducible skeletal sites for performing areal bone mineral density (BMD) measurements. Our objective is to evaluate the role of measurement of femoral neck BMD in avoiding the under-diagnosis of low BMD being a risk for fractures in subjects with chronic medical conditions that might affect bone health. Material and methods: Subjects with chronic medical conditions that might affect bone health were studied (n = 468) and 36 healthy children were recruited as control subjects. Physical examinations, height, weight measurements and BMI were calculated. Dual-energy radiographic absorptiometry of the lumbar spine and femoral neck were measured. Results: Bone mineral density z scores in both sites were significantly reduced in chronic patients, compared with control subjects. Prevalence of very low BMD z scores (–2 or more) using lumbar DXA, femoral DXA, and either of the sites were 1.38%, 3.37%, and 3.96%, respectively, while low BMD Z scores (–1 to less than –2) were 9.52%, 18.05% and 21.14% respectively. Conclusions: We identified a significant decrease in both lumbar and femoral BMDs in studied children. Sometimes femoral BMD is decreased while lumbar BMD is still within the normal range. For this reason we recommend that, when technically feasible and there is no facility to measure TBLH, all those patients should have lumbar spine and femoral neck bone mineral density measurements to avoid under-diagnosis of low BMD being a risk for fractures. Key words: osteoporosis, bone density, chronic diseases. Introduction Bone health in children is increasingly recognised in paediatric practice. Low bone mineral density (BMD) can result from a wide variety of childhood diseases and the treatments [1, 2]. The classical definition of osteoporosis should be valid at any age, yet its practical applicability to children and adolescents remains a matter of debate and there is no consensus on a diagnosis based solely on the BMD value. The clinical relevance of uncomplicated low bone density in the young and its long-term consequences remain difficult to evaluate and there is only preliminary evidence that the BMD value is a predictor of fracture risk in growing subjects [3]. Corresponding author: Prof. Nagwa Abdallah Ismail Paediatrics Department, National Research Centre Albhoss Street Cairo, Egypt E-mail: nagwa_abdallah@ yahoo.com