Abstract
We studied bone mineral status using dualβenergy Xβray absorptiometry (DXA) on 150 singleton newborn infants with birth weights 1002β3990 g and gestational ages (GA) 27β42 weeks. Eightyβfive infants were preterm (<38 weeks), and 79 infants were low birth weight (β€2500 g). In addition, we aimed to determine the predictive value of anthropometric measurements, race, and gender on variability in bone mineral status. Data were acquired using a whole body DXA scanner with a pediatric platform. Scan analyses were performed with software version V5.64P. Results showed a highly significant (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 38β42 weeks, birth weight 2700β3990 g), the mean TB BMC was 68.2 g, TB area 307.6 cm^2^, and TB BMD 0.221 g/cm^2^. 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;11:997β1002)