Abstract OBIECTIVE: To study the bone mineral development and the factors influencing the development in preterm infants. METHODS: Ninety preterm and 90 term infants followed up by the child health care service were randomly enrolled. Tibia quantitative ultrasound measurements were used to evaluate bone mineral density described as supersonic speed of sound (SOS) and Z scores at 6 months old (corrected gestational age for preterm infants). The factors influencing bone mineral development were investigated by questionnaire. RESULTS: The SOS values and Z scores in term infants were significantly higher than those in preterm infants at 6 months old. In the preterm group, the SOS values and Z scores were significantly different in infants with different birth weights or gestational ages (P<0.05). The SOS values in preterm infants with different weaning time were significantly different. The Z scores in female preterm infants were significantly higher than that in males (P<0.05). Multiple regression analysis indicated that weaning time and daily time of outdoor activities were independent factors influencing SOS values in preterm infants. CONCLUSIONS: It is helpful to promote bone mineral development by an appropriate weaning time or increasing the time of outdoor activities in preterm infants.
［1］Eliakim A, Nemet D, Ahmad I, Zaldivar F, Koppel R, Grochow D, et al. Growth factors, inflammatory cytokines and postnatal bone strength in preterm infants［J］. J Pediatr Endocrinol Metab, 2009, 22(8): 733-740.
［2］Baroncelli GI. Quantitative ultrasound methods to assess bone mineral status in children: technical characteristics, performance, and clinical application［J］. Pediatr Res, 2008, 63(3): 220-228.
［3］McDevitt H, Ahmed SF. Quantitative ultrasound assessment of bone health in the neonate［J］. Neonatology, 2007, 91(1): 2-11.
［4］Bagnoli F, Toti MS, Conte ML, Badii S, Mori A, Tomasini B, et al. Quantitative ultrasound for the assessment of bone in the preterm infant［J］. Minerva Pediatr, 2010, 62(2): 125-132.
［5］Fewtrell MS, Williams JE, Singhal A, Murgatroyd PR, Fuller N, Lucas A. Early diet and peak bone mass: 20 year follow-up of a randomized trial of early diet in infants born preterm［J］. Bone, 2009, 45(1): 142-149.
［8］Fewtrell MS, Loh KL, Chomtho S, Kennedy K, Hawdon J, Kha-koo A. Quantitative ultrasound (QUS): a useful tool for monitoring bone health in preterm infants?［J］. Acta Paediatr, 2008, 97(12): 1625-1630.
［9］Ritschl E, Wehmeijer K, DE Terlizzi F, Wipfler E, Cadossi R, Douma D, et al. Assessment of skeletal development in preterm and term infants by quantitative ultrasound［J］. Pediatr Res, 2005, 58(2): 341-346.
［10］Jarjou LM, Prentice A, Sawo Y, Laskey MA, Bennett J, Goldberg GR, et al. Randomized, placebo-controlled, calcium supplementation study in pregnant Gambian women: effects on breast-milk calcium concentrations and infant birth weight, growth, and bone mineral accretion in the first year of life［J］. Am J Clin Nutr, 2006, 83(3): 657-666.
［11］Kent JC, Arthur PG, Mitoulas LR, Hartmann PE. Why calcium in breastmilk is independent of maternal dietary calcium and vitamin D［J］. Breastfeed Rev, 2009, 17(2): 5-11.
［12］Abalos E, Merialdi M, Wojdyla D, Carroli G, Campodónico L, Yao SE, et al. Effects of calcium supplementation on fetal growth in mothers with deficient calcium intake: a randomised controlled trial［J］. Paediatr Perinat Epidemiol, 2010, 24(1): 53-62.
［13］Chen HL, Lee CL, Tseng HI, Yang SN, Yang RC, Jao HC. Assisted exercise improves bone strength in very low birthweight infants by bone quantitative ultrasound［J］. J Paediatr Child Health, 2010, 46(11): 653-659.
［14］Moyer-Mileur L, Ball S, Brustetter V,Chan G.Maternal-administered physical activity enhances bone mineral acquisition in premature very low birth weight infants［J］. J Perinatol, 2008, 28(6): 432-437.
