定量超声技术对婴儿出生时骨状况的研究

目的　评价定量超声(QUS)技术在新生儿中的应用,取得新生儿出生时骨QUS的基础资料。方法　采用以色列Sunlight公司生产的Omnisense定量超声仪,对 157例新生儿进行出生时胫骨声波速度(SOS)测量。结果　 ①男女婴儿之间SOS值差异无统计学意义 (男 88例,SOS值为2968±115m/s;女 69例,SOS值为 2956±105m/s;P=0. 524)。早产儿 (68例,平均胎龄 33 0±2. 5周)SOS值平均为 2935±96m/s,足月儿(89例, 平均胎龄 39. 4±1 3周)SOS值平均为 2984±116m/s,早产儿SOS值显著低于足月儿 (t=2 837,P=0. 005)。②不同季节出生的新生儿其SOS值差异有统计学意义(F=4.377,P=0 005);新生儿SOS值在春夏季出生者显著低于秋冬季出生者,夏季出生者比冬季出生者低 2 3%。③出生体重<1500g新生儿SOS值 (11例,SOS值为 2908±99m/s)显著低于出生体重>2500g新生儿(86例,SOS值为 2980±113m/s) (P=0 .042)。④在 109例适于胎龄儿中,SOS值与胎龄显著相关(r=0.270,P=0 .005),与出生体重也显著相关 (r=0. 232,P=0 015),多元回归分析发现胎龄和出生季节是影响SOS值的重要因素 (F=8 515.P<0. 001,校正决定系数R2 =0. 141)。结论　QUS适用于新生儿骨状况的研究;本研究取得了新生儿出生时骨SOS值的资料。

Examination of infant bone status with quantitative ultrasound at birth

OBJECTIVE: Quantitative ultrasound (QUS) is a new method of evaluating Children's bone status, including bone mineral density and bone strength. The bone nutrition during fetal and early neonatal period is very important for the human bone development of whole life. The objective of this study was to evaluate the clinical application of QUS for newborn infants and to obtain the QUS data for normal neonates including premature infants. METHODS: An ultrasound bone sonometer, Omnisense, produced by Sunlight company of Israel, was applied to measure the bone speed of sound (SOS) of tibia in 157 neonates including 68 premature infants in the first week of life. RESULTS: (1) No significant difference in SOS was found between male (n = 88, SOS = 2968 +/- 115 m/s) and female infants (n = 69, SOS = 2956 +/- 105 m/s) (P = 0.524). The SOS of premature infants (n = 68, mean gestational age 33.0 +/- 2.5 weeks) and full-term infants (n = 89, mean gestational age of 39.4 +/- 1.3 weeks) were 2935 +/- 96 m/s and 2984 +/- 116 m/s, respectively, at birth and there was significant difference between them (P = 0.005). (2) There were significant differences of SOS in neonates who were born in different seasons (F = 4.377, P = 0.005); the significant difference remained (F = 3.933, P = 0.010) after the influences of gestational age and birth weight were eliminated. The SOS in neonates born in spring (March, April and May) and summer (June, July and August) were significantly lower than that of those born in autumn (September, October and November) and winter (December, January and February). The SOS in neonates born in summer was about 2.3% (75/2999) was lower than that of those born in winter. (3) Significant difference of SOS was observed between neonates with different birth weight < 1500 g (n = 11), SOS = 2968 +/- 115 m/s; and > 2500 g (n = 86), SOS = 2980 +/- 113 m/s; P = 0.042]. (4) Significant correlations were found between SOS and gestational age (r = 0.270, P = 0.005), and between bone SOS and birth weight (r = 0.232, P = 0.015) in appropriate for gestational age (AGA) infants (n = 109); however, no such significant correlations were found in small for gestational age (SGA) infants or large for gestational age (LGA) infants. Multiple regression analysis showed that gestational age and the birth season were two important factors which may contribute to bone SOS of neonates at birth (n = 157, F = 8.515, P < 0.001, adjusted R(2) = 0.141), when the analysis was carried out with SOS as dependent variable and gestational age, birth weight, chronological age, calf length and the birth season as independent variables. CONCLUSION: QUS is a new method which is suitable for evaluating the bone status of neonates and it is free of radiation, non-invasive, the machine is portable and easy to manipulate at infant bed side. The present study suggests the need for particular care for the bone status in premature infants and supplement of vitamin D in pregnant women.