The Journal of the Arkansas Medical Society Med Journal June 2020 | Page 12

EDITORIAL PANEL: Chad T. Rodgers, MD, FAAP | Elena M. Davis, MD, MPH | Shannon Edwards, MD | William L. Mason, MD | J. Gary Wheeler, MD, MPS Pediatric Osteoporosis Management is Critical LAURA J. HOBART-PORTER, DO, FAAPMR Osteoporosis is a condition commonly ascribed to elderly people, but it can also be a serious condition in children. The incidence of pediatric osteoporosis is not known, but there are several disease processes that place children at higher risk. Appropriate management of pediatric osteoporosis is critical, given that 90% of bone density is determined by puberty, and consequences for missing it can be debilitating and life long. 1 Bone development begins in fetal life and is influenced by maternal factors including substance exposure (smoking, caffeine, alcohol), vitamin D deficiency, activity level, intrauterine growth restriction and diabetes, all of which adversely influence bone development. As a child develops, prematurity, genetics, diet, mobility, chronic disease and medications also convey an increased risk of lower bone density. 2,3 The primary means of assessing bone density in children remains pediatric dual-energy X-ray absorptiometry (DXA). For children, studies should be ordered at a facility capable of controlling for age and stature for a more accurate measurement. Children should be able to lie flat on an exam table. Significant contractures, hip dislocation and the presence of orthopedic instrumentation limit the data that DXA can collect. There are no reliable norms for children under age 3. Children weighing less than 20 kg. or smaller than 115 cm. may not have references available for their size, rendering data of little utility. Consistent measurement approaches from year to year allow reliable monitoring of disease progression. Measure DXA annually in at-risk populations. 3 There are other means of assessment beyond DXA, but lack of age and stature-related norms makes interpretation difficult. Plain radiographs can be used to estimate bone density in younger children, but this is a highly subjective method without normative data. Quantitative computed tomography, quantitative ultrasonography and magnetic resonance imaging offer an assessment of bone structure in addition to bone density itself. 3 However, these are most often employed in research settings. Lack of normative data is a limitation in the pediatric population. In 2013, the International Society of Clinical Densitometry published a Pediatric Position Statement, delineating the differences between adult and pediatric osteoporosis. Osteopenia in adults is defined as DXA Z-score between -1 and -2.5; osteoporosis is defined as DXA less than 2.5. In children, a Z-score less than -2 is called “low bone density,” not osteopenia. Z-scores less than or equal to -2 with clinically significant fracture(s) meet criteria for osteoporosis. The Society defines clinically significant fractures as one or more vertebral compression fractures, two or more long bone fractures by age 10, or three or more long bone fractures up to age 19. 2 When low bone density (LBD) is identified, it is important to address the etiology. Laboratory tests of alkaline phosphatase, osteocalcin, type I procollagen, calcium, phosphate and vitamin D-25OH can help determine if LBD is related to a modifiable risk factor. Low vitamin D levels are common within pediatric populations. Levels less than 20 ng/ mL are considered low; borderline low is less than 30. Children with disabilities that contribute to LBD may need vitamin D levels ranging 276 • The Journal of the Arkansas Medical Society www.ArkMed.org