Ogilvy-Stuart A L, Hands S J, Adcock C J, Holly J M, Matthews D R, Mohamed-Ali V, Yudkin J S, Wilkinson A R, Dunger D B
Department of Pediatrics, University of Oxford, United Kingdom.
J Clin Endocrinol Metab. 1998 Oct;83(10):3550-7. doi: 10.1210/jcem.83.10.5162.
The relationship between GH, insulin-like growth factor I (IGF-I), IGF-binding protein-1 (IGFBP-1), and insulin may be critical to the understanding of variation in early growth, especially in the small for gestational age (SGA) baby. To investigate these relationships, we have undertaken 12-h hormone profiles in 26 babies (13 SGA) at a median of 4.5 days of age. GH levels were measured every 10 min; insulin and IGFBP-1 were measured every 20 min. Mean levels of these hormones and IGF-I levels (from a single sample) were related to size at birth. The GH data were analyzed by Pulsar and time series analysis to characterize hormone pulsatility and relationship with feeds. IGF-I levels correlated with birth weight and length (r2 = 0.47; P = 0.004, and r2 = 0.5; P = 0.0005, respectively, after allowing for gestation), whereas mean GH levels were negatively related to birth size (r2 = -0.18; P = 0.04 and r2 = -0.2; P = 0.03 for weight and length, respectively). No direct relationship between mean GH levels and IGF-I was identified. IGF-I levels were higher in appropriate for gestational age (AGA; mean +/- SD, 82+/-61 ng/mL) than in SGA (34+/-22 ng/mL; P = 0.03) babies. Baseline (mean +/- SD, 25.9+/-11.9), mean (33.9+/-14.0), and peak (45.0+/-18.1 microg/L) GH levels were higher in SGA than in AGA babies [17.1+/-8.2 (P = 0.04), 22.5+/-10.4 (P = 0.03), and 30.7+/-15.4 microg/L (P = 0.04), respectively]. Mean IGFBP-1 levels were also higher in SGA than AGA babies (157.4+/-90.7 vs. 62.7+/-43.8 ng/mL; P = 0.01). A positive correlation was identified between changes in insulin and coincident pulses of GH (r = 0.147; P < 0.01), whereas there was an inverse relationship between insulin and IGFBP-1, with a lag time 120 min (r = -0.33; P < 0.0001). In conclusion, these studies indicate that the GH-IGF-I axis is closely related to feeding in the newborn. In SGA babies, low IGF-I and elevated IGFBP-1 reflect the slow growth, but elevated GH and rapid GH pulsatility may be a signal for lipolysis.
生长激素（GH）、胰岛素样生长因子I（IGF-I）、IGF结合蛋白-1（IGFBP-1）和胰岛素之间的关系对于理解早期生长变化可能至关重要，尤其是对于小于胎龄（SGA）儿。为了研究这些关系，我们对26例婴儿（13例SGA）在中位年龄4.5天时进行了12小时的激素谱测定。每10分钟测量一次GH水平；每20分钟测量一次胰岛素和IGFBP-1。这些激素的平均水平以及IGF-I水平（来自单个样本）与出生时的大小相关。通过Pulsar和时间序列分析对GH数据进行分析，以表征激素的脉冲性及其与喂养的关系。IGF-I水平与出生体重和身长相关（校正孕周后，r2分别为0.47；P = 0.004和r2 = 0.5；P = 0.0005），而平均GH水平与出生大小呈负相关（体重和身长的r2分别为-0.18；P = 0.04和r2 = -0.2；P = 0.03）。未发现平均GH水平与IGF-I之间存在直接关系。适于胎龄（AGA）儿的IGF-I水平（平均±标准差，82±61 ng/mL）高于SGA儿（34±22 ng/mL；P = 0.03）。SGA儿的基线（平均±标准差，25.9±11.9）、平均（33.9±14.0）和峰值（45.0±18.1 μg/L）GH水平高于AGA儿[分别为17.1±8.2（P = 0.04）、22.5±10.4（P = 0.03）和30.7±15.4 μg/L（P = 0.04）]。SGA儿的平均IGFBP-1水平也高于AGA儿（157.4±90.7 vs. 62.7±43.8 ng/mL；P = 0.01）。胰岛素变化与同时出现的GH脉冲之间存在正相关（r = 0.147；P < 0.01），而胰岛素与IGFBP-1之间存在负相关，滞后时间为120分钟（r = -0.33；P < 0.0001）。总之，这些研究表明，GH-IGF-I轴与新生儿的喂养密切相关。在SGA儿中，低IGF-I和升高的IGFBP-1反映了生长缓慢，但升高的GH和快速的GH脉冲性可能是脂肪分解的信号。
