新生儿瘦素水平动态变化与胰岛素样生长因子—Ⅰ、胰岛素及生长激素关系研究

Study for dynamic changes of serum leptin and their relationship with insulin-like growth factor(IGF-I),insulin and growth hormone levels in neonates

目的：探讨新生儿期血清瘦素、胰岛素样生长因子—I（IGF—I）、胰岛素、生长激素水平变化及其对新生儿生长发育的影响。方法：采用放射免疫法检测100例正常足月人工喂养新生儿脐静脉和静脉血瘦素、IGF—I、胰岛素和生长激素水平，并按采血时间分为初生脐血组、早期新生儿组（生后4～6天）和晚期新生儿组（生后25～28天），采用新生儿体重、身长和RI指数评估新生儿生长发育情况。结果：脐血瘦素水平与IGF—I、胰岛素、生长激素水平和出生体重呈正相关，r值分别为0.45、0.374、0.56和0.646（P均〈0.01）；早期新生儿组血清瘦素水平（O．45±0．38）μg／L显著低于初生脐血组（8．51士5．64）μg／L，其下降值与此期间IGF—I的下降值呈显著正相关（r=0．28），而与胰岛素、生长激素和新生儿体重的下降值无关：晚期新生儿瘦素水平（1．83±0．73）μg/L回升，高于早期新生儿水平（P〈0．01），其增长值与血清IGF—I、胰岛素、生长激素以及体重的增长值呈显著正相关，r值分别为0．45、0．384、0．289、0．484（P〈0．01—0．05）。结论：新生儿期血清瘦素水平的动态变化与体重、血清IGF—I、胰岛素和生长激素水平有一定相关性，提示瘦素对新生儿期生长发育和能量代谢方面发挥重要作用：瘦素可能通过营养物质一胰岛素--IGF—1—生长激素内分泌轴共同调控新生儿生长发育。

Objective： To investigate the dynamic changes of serum leptin, insulin- like growth factor （IGF-I）, insulin and growth hormone levels in newboms and to study the effect of them on the neonatal growth and development. Methods： The serum levels of leptin, IGF- I, insulin and growth hormone in one hundred healthy and artificial feeding neonates were measured by radioimmunoassay. Body weight, body length and Rohrers Index （RI） were used to evaluate the growth and development of newborn. Results： Cord venous serum leptin levels significantly correlated with IGF-I, insulin, growth hormone and birth weight （r=0.45,0.374,0.56 and 0. 646, respectively）（Pall〈0.01）.The serum leptin levels at 4～6 days （0.45±0.38） μg/L were both significantly lower than those at birth （8.51±5.64）μg/L and those at 25～28 days （1.83±0.73） μg/L.The decrease of serum of leptin levels significantly correlated with the reduced level of serum IGF-I, but did not correlate with the body weight loss, the reduced levels of serum insulin and growth hormone occurred between at birth and 446 days. The rise of serum leptin levels significantly correlated with the body weight gain as well as with the rise of IGF-I, insulin and growth hormone levels occurred between 446 days and 25～28 days（r =0.45,0.384,0.289 and 0.484, respeetively）（P〈0.01～0.05）. Conclusion： Dynamic changes of serum leptin levels during neonatal period showed positive correlation with the variation of body weight, serum IGF-I , insulin and growth hormone. It was suggested that leptin play an important role in the neonatal growth and development and energy metabolism and might collaborate with IGF- I, insulin and growth hormone at the nutrient substance--insulin- -IGF-I--growth hormone axis to regulate the neonatal growth and develooment.