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

摘要： 目的 分析胎龄小于34周早产儿骨骼早期发育的影响因素,为早产儿代谢性骨病的早期预防提供依据。方法 选取2017年5月-2018年12月在苏州市立医院出生胎龄＜34周的早产儿224例,于矫正3月龄进行左侧胫骨中段超声骨强度测定。通过本院住院系统与儿童保健早产儿管理档案搜集与骨骼发育相关的资料。结果 224例早产儿矫正3月龄超声骨强度Z值为-1.4(-0.6,-2.0),其中,79例(35.27%)超声骨强度值正常,43例(19.20%)轻度骨强度不足,38例(16.96%)中度骨强度不足,64例(28.57%)重度骨强度不足。女婴(OR=4.184,95%CI:1.876~9.329,P＜0.001)、出生胎龄≤31周(OR=2.854,95%CI:1.282~6.352,P=0.010)、新生儿静脉营养(全肠外)≥7 d(OR=3.180,95%CI:1.480~6.832,P=0.003)、新生儿咖啡因使用≥10 d(OR=5.673, 95%CI:1.820~17.686,P=0.003)、住院期间碱性磷酸酶(ALP)峰值≥400 U/L(OR=2.796,95%CI:1.065~7.341,P=0.037)是发生早产儿超声骨强度不足的危险因素;而母亲妊娠糖尿病(OR=0.312,95%CI:0.139~0.698,P=0.005)、母亲妊娠高血压(OR=0.191,95%CI:0.065~0.560,P=0.003)是发生早产儿超声骨强度不足的保护因素;相比纯母乳喂养,出院后以普通配方奶(OR=0.145,95%CI:0.058~0.363,P＜0.001)、早产儿出院后配方奶(OR=0.168,95%CI:0.062~0.455,P＜0.001)与强化母乳(OR=0.219,95%CI:0.063~0.765,P=0.219)的喂养方式是发生早产儿超声骨强度不足的保护因素。短期小剂量钙剂或更高剂量维生素D₃(800 U/d)的补充对早产儿超声骨强度的影响无统计学意义。结论 早产儿早期健康管理工作中,应更加重视出生胎龄≤31周、新生儿静脉营养(全肠外)≥7 d、新生儿咖啡因使用≥10 d、住院期间ALP峰值≥400 U/L以及出院后以纯母乳喂养的早产儿,充足钙磷制剂的补充,尽早预防早产儿骨病的发生。

关键词: 超声骨强度, 早产儿, 代谢性骨病