Dual-energy X-ray absorptiometry studies of bone mineral status in newborn infants

Abstract
We studied bone mineral status using dual‐energy X‐ray absorptiometry (DXA) on 150 singleton newborn infants with birth weights 1002–3990 g and gestational ages (GA) 27–42 weeks. Eighty‐five infants were preterm (p < 0.001 for all comparisons) correlation among the continuous independent variables, gestational age, birth weight, study weight, study bare weight, and study length, and between independent and each of the dependent variables, total body bone mineral content (TB BMC), TB area, and TB bone mineral density (TB BMD). The best single determinant of bone mineral status is body weight, accounting for 95% of TB BMC and TB area and for 86% of TB BMD variation. Body length was the only additional significant predictor of TB area. Inclusion of postnatal age (during the first week after birth), race, gender, or season, either individually or in combination, failed to improve bone mineral status explanation. By term (GA 38–42 weeks, birth weight 2700–3990 g), the mean TB BMC was 68.2 g, TB area 307.6 cm2, and TB BMD 0.221 g/cm2. We conclude that DXA can be performed even in small preterm infants during the newborn period. Our results can be used as a basis for further studies in physiologic and pathologic situations that might affect bone mineralization in infants. (J Bone Miner Res 1996;11:997‐1002)