«Early attempts to measure bone density utilized plain skeletal radiography»
tends to be higher in African Americans than in other groups. Height is important, because DXA provides lower bone density readings for shorter children, which can be corrected using a recently developed algorithm that adjusts for height. Therefore, a clinician must know a child’s height to interpret DXA measurements, particularly of the spine, correctly in children with short stature. Similarly, a child’s pubertal status must be considered when analyzing bone densitometry, as children with delayed maturation will have lower bone mass than their peers who have higher levels of estrogen or testosterone.
A 2004 study found significant
overdiagnosis of pediatric osteoporosis among children who had been referred to an osteoporosis trial on the basis of low bone mineral density (BMD) scores inferred from DXA. In that study, 88 percent of the scans had one or more errors in interpretation, including non- gender-specific reference data, inattention to short stature, and the incorrect use of a T-score instead of a Z-score. After correcting for these errors, 53% of the children who been referred for low BMD scores were found to have normal bone mineral density. A final point to bear in mind is that the
reference databases have not been compiled specific to Middle Eastern populations.
CONCLUSION Clearly, refinements in reference data will improve the accuracy of clinical assessments of bone health in children and
adolescents. Recently, the International Society for Clinical Densitometry (ISCD) issued recommendations for DXA interpretation in children. The ISCD stated that an appropriate reference dataset must include “a sample of the general healthy population sufficiently large to characterize the normal variability in bone measures that takes into consideration sex, age and race/ethnicity.” Another recommendation stated
that “In children with linear growth or maturational delay BMC and BMD results should be adjusted for absolute height or height age, or compared to pediatric reference data that provide age-, sex-, and height-specific Z-scores.” Specific therapy for children with low bone density is best left to clinicians who are highly experienced in the evaluation and management of pediatric bone disorders. Available agents for adults with osteoporosis and other pharmacologic treatments may be useful in selected circumstances for children with low bone density, but such children must be treated very carefully as long-term safety data are not yet available. In summary, evaluation of bone
density by DXA is appropriate for children and adolescents who have a history of fragility fracture or specific risk factors for low bone density. As better diagnostic techniques become available and specific criteria for diagnosis are developed, it is likely that pediatric-specific pharmacologic agents will be forthcoming. Until that time, it is reasonable to refer children and adolescents who have a suspected metabolic bone disease to a pediatric bone specialist (see figure 4). ■
AH
REFERENCES References available on request (
magazine@iirme.com)
LEARN MORE
The Primary Healthcare Exhibition, part of the Abu Dhabi Medical Exhibition and Congress, is the premier business- to-business forum for the Middle East’s Primary healthcare sector. New for 2011 is the integration of PHARMA, aimed directly at key pharmaceutical suppliers and distributors, further enhancing this sector’s audience. For more information about the event, visit
www.abudhabimed.com
40
www.lifesciencesmagazines.com
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64