关键词: 超声骨强度, 早产儿, 代谢性骨病

Abstract: Objective To explore the factors affecting ultrasound bone mineral density (BMD) in premature infants, so as to provide reference for early prevention of metabolic bone disease. Methods Totally 224 premature infants with gestational age＜34 weeks were recruited in this study from May 2017 to December 2018 in Suzhou Municipal Hospital.Tibial BMD was measured at the corrected age of 3 months old.Data related to the early skeletal development of premature infants were collected by in-patient management information system and health records in child healthcare department. Results The Z scores of tibial BMD in 224 premature infants at the corrected age of 3 months were-1.4(-0.6,-2.0).Among them, tibial BMD Z scores of 79(35.27%) cases were normal, 43(19.20%) cases were mild BMD deficiency, 38(16.96%) cases were modest BMD deficiency, and 64 (28.57%) cases were severe BMD deficiency.Female gender(OR=4.184, 95%CI:1.876-9.329, P＜0.001), gestational age ≤ 31 weeks (OR=2.854, 95%CI:1.282-6.352, P=0.010), duration of intravenous nutrition ≥7 days (OR=3.180, 95%CI:1.480-6.832, P=0.003), duration of caffeine therapy ≥10 days (OR=5.673, 95%CI:1.820-17.686, P=0.003), the peaks of alkaline phosphatase (ALP)≥400 U/L during hospitalization (OR=2.796, 95%CI:1.065-7.341, P=0.037) were risk factors for BMD deficiency.However, the Z scores of tibial BMD was significantly higher in premature infants with maternal gestational diabetes (OR=0.312, 95%CI:0.139-0.698, P=0.005) or gestational hypertension (OR=0.191, 95%CI: 0.065-0.560, P=0.003).Compared with exclusively breastfeeding after discharge, common formula-feeding (OR=0.145, 95%CI:0.058-0.363, P＜0.001), nutrient-enriched formula-feeding (OR=0.168, 95%CI:0.062-0.455, P＜0.001) and human milk fortifier-feeding (OR=0.219, 95%CI:0.063-0.765,P=0.219) may reduce the risk of BMD deficiency.There were no significant difference in Z score among infants who had calcium supplementation and higher-dose vitamin D₃ (800 U/d) supplementation or not. Conclusions In the early health management, more attention should be paid to the infant with high risk indicators associated with BMD deficiency, such as gestational age ≤31 weeks, duration of intravenous nutrition≥7 days, duration of caffeine therapy ≥10 days, ALP ≥ 400 U/L during hospitalization.In addition, exclusively breastfed prematures are suggested to take adequate calcium and phosphorus supplementation, thus preventing bone disease in preterm infants.

Key words: ultrasound bone mineral density, premature infants, metabolic bone disease