婴儿早期骨代谢生化指标与声波速度值和出生后年龄间的关系

目的 探讨婴儿早期骨代谢生化指标与声波速度值和出生后年龄间的关系.方法 采用骨定量超声(QUS)仪对167例出生3月内的婴儿进行胫骨声波速度(SOS)测量.其中包括53例早产儿(胎龄:32.6±2.7周)和114例足月儿(胎龄:39.1±1.2周);同时在部分婴儿中测量血钙、磷、碱性磷酸酶(ALP)和骨碱性磷酸酶(BALP).结果 ①早产儿和足月儿的血钙、磷、ALP和BALP值之间均差异无显著性.②婴儿骨SOS值与ALP呈显著负相关(n=167,r=-0.139,P=0.036)、与BALP也显著负相关(n=32,r=-0.410,P=0.010);SOS值与血钙、血磷及血钙磷乘积无显著性相关.在早产儿中,ALP和BALP与日龄均显著相关,相关系数r分别为0.286(n=53,P=0.019)和0.946(n=7,P=0.001);在足月儿中未发现显著相关性.血磷与日龄呈显著负相关(n=24,r=-0.509,P=0.005).③ALP与BALP高度相关(n=32,r=0.958,P=0.001),BALP占ALP活力的47.3%.早产儿在出生时BALP和Ⅰ型胶原羧基端肽(IcTP)显著正相关(n=36,r=0.768,P=0.001).结论 定量超声技术测量SOS有助于我们评估婴儿早期骨状况;在此横向研究中我们发现骨SOS与骨代谢生化指标之间存在相关性,然而,二者间的纵向关系有待于进一步研究.

Correlations among biochemical markers of bone turnover,bone speed of sound and postnatal age in early infancy

Objective To examine the correlations among biochemical markers of bone turnover,bone speed of sound and postnatal age in early infancy. Materials and methods: A quantitative ultrasound bone sonometer was used to measure the bone speed of sound (SOS) of the tibia in 167 infants within 3 months of birth, including 53 preterm infants (gestational age 32.6±2.7 weeks) and 114 full-term infants (gestational age 39.1±1.2 weeks). Serum calcium, phosphorus, bone alkaline phosphatase (ALP), bone alkaline phosphatase (BALP) were examined at the same time among some of them. Results: 1) There were no significant differences of serum calcium, phosphorus, ALP and BALP between preterm infants and full-term infants. 2) There were significantly inverse correlations between SOS and ALP (n=167,r=-0.139,P=0.036), as well as between SOS and BALP (n=32,r=-0.410,P=0.010) in infants, however, no such relationships between SOS and serum calcium,phosphorus, and calcium phosphorus product (serum calcium multiplied by serum phosphorus) were found. When infants were divided into two groups: in preterm infants there were significant correlations between ALP and postnatal day(n=53,r=0.286,P=0.019)and also between BALP and postnatal day(n=7,r=0.946,P=0.001); But in full-term infants, no such relationships were found. There were significantly inverse correlations between serum phosphorus and postnatal day (n=24,r=-0.509,P=0.005). 3) ALP was significantly correlated with BALP(n=32,r=0.958,P=0.001)and BALP accounted for 43.7% of total value of ALP. There was significantly correlation between BALP and carboxyterminal telopeptide type I collangon (IcTP) in preterm infants at birth (n=36,r=0.768,P=0.001). Conclusions: Measurement of SOS with QUS is able to help us to evaluate bone status during early infancy. While in this cross-sectional study we have found some correlations between bone SOS and biochemical indexes of bone turnover in China, the long-term relationships among them remain to be studied further.