新生适于胎龄儿血清瘦素与骨声波传导速度的关系

摘要

目的：探讨新生适于胎龄儿血清瘦素、骨声波传导速度(SOS)随胎龄的变化，以及瘦素与新生儿骨SOS的关系。方法共收集65例新生适于胎龄儿，根据胎龄分为早期早产儿组(胎龄31~34周，14例)，晚期早产儿组(胎龄34~37周，13例)，足月儿组(胎龄≥37周，38例)。所有研究对象均测量出生体质量、身长、小腿长度，采用Ponderal指数(PI)估测新生儿营养状态，采用weststrate公式(F%)估测新生儿体脂含量。生后7 d内采集静脉血测定血清瘦素水平，同时采用超声定量技术测量左侧胫骨SOS。结果三组新生儿胎龄、出生体质量、身长、小腿长度、F%、PI、血清瘦素与骨SOS的差异均有统计学意义(F=11.90~140.20，P均<0.01)；各变量均随胎龄增大而增大(P均<0.05)。Pearson相关分析提示，除足月儿身长、PI外，三组新生儿的血清瘦素与其胎龄、出生体质量、身长、PI、F%呈显著正相关(r=0.36~0.78， P均<0.05)。三组新生儿骨SOS分别与其瘦素、胎龄、出生体质量及小腿长度呈显著正相关(r=0.33~0.76，P均<0.05)。进一步多元线性逐步回归分析发现，仅新生儿的胎龄(β=0.39，P=0.014)和出生体质量(β=0.44，P=0.006)对其骨SOS的影响具显著性。结论新生适于胎龄儿血清瘦素及骨SOS均与胎龄、出生体质量呈正相关，瘦素对骨SOS有影响，但不是其直接影响因素。%Objective To investigate the changes of serum leptin and bone speed of sound (SOS) with gestational age (GA) and relationship between leptin and bone SOS in appropriate-for-gestational-age (AGA) neonates. Methods A total of 65 AGA neonates were recruited and divided into three groups according to their gestational age:preterm infant (GA 31-34 w, 14 cases), late preterm infant (GA 34-37 w, 13 cases), and full-term infant (GA≥37 w, 38 cases). Anthropometric parameters, including birth weight, length, leg length, skin fold thickness were measured in all the subjects, and the neonatal nutritional status and body fat content were evaluated by Ponderal Index (PI) and Weststrate equation (F%) respectively. Serum leptin concentration and tibial SOS were measured within 7 days after birth. Results There were signiifcant differences in GA (F=140.199, P<0.001), birth weight (F=47.042, P<0.001), birth length (F=46.877, P<0.001), leg length (F=17.543, P<0.001), PI (F=11.898, P<0.001) and F%( F=21.955, P<0.001) among three groups. Serum leptin and tibial SOS were signiifcantly different among these groups ( F=49.724, 20.052 respectively, P<0.001), and both of them were positively correlated with gestational age and birth weight (P<0.01). In addition, leptin was positively correlated with tibial SOS, but the correlation disappeared after adjustment for GA and anthropometry. According to the multivariate forward stepwise regression analysis, tibial SOS was found to be signiifcantly positively associated with gestational age and birth weight in the three groups. Conclusions Both bone SOS and serum leptin are signiifcantly correlated with gestational age and birth weight in AGA neonates, and leptin is related with but not the independent direct predictor of bone SOS.