Hermida R C, García L, Ayala D E, Fernández J R
Bioengineering Laboratory, ETSI Telecomunicación, University of Vigo, Spain.
Clin Endocrinol (Oxf). 1999 Apr;50(4):473-9. doi: 10.1046/j.1365-2265.1999.00674.x.
When studying the relationship between spontaneous secretion of growth hormone (GH) and cortisol in children, most studies show no correlation in mean levels of these two hormones, while others found positive or even strongly negative correlations. These contradictory results could be partly due to the inability to properly compare hormones that are characterized by circadian and ultradian variations in their secretory profiles. We aim here to study possible differences in rhythm characteristics of plasma cortisol with stature and to compare the circadian secretory patients of cortisol and GH.
We analysed data from 135 prepubertal children: (1) 14 GH-deficient children; (2) 36 children with short stature (2-3 SD below their peer group mean); (3) 57 children with very short stature (3-4 SD below their peer group mean); and (4) a reference group of 28 children with normal stature (+/- 2 SD). Subjects were living in a hospital setting on a diurnal waking (07.30-22.30 h), nocturnal resting routine during sampling, consuming the usual hospital diet at fixed times.
Cortisol and GH concentrations were determined by radioimmunoassay in plasma obtained at about 2-3 h intervals during most of the day and at half-hour intervals between 22.00 and 02.00 h. Circadian rhythm characteristics obtained by least-squares estimation were compared between groups divided according to gender and stature with a parameter test.
Show a statistically significant circadian rhythm in cortisol secretion for all groups studied (P < 0.001 in all cases). A comparison of circadian parameters indicated similar characteristics between subjects of short, very short and normal stature. Despite a borderline statistically significant difference in rhythm-adjusted mean and amplitude of GH between nondeficient and GH-deficient children, there was no difference in the circadian pattern of cortisol secretion between these two groups. No correlation was found in circadian mean, amplitude, average, standard deviation, standard error, minimum or maximum between GH and cortisol for any of the groups of children.
Any possible relation between GH and cortisol remains unclear. Moreover, GH-deficient children are not necessarily characterized by either hyper- or hypocortisolaemia.
在研究儿童生长激素（GH）的自发分泌与皮质醇之间的关系时，大多数研究表明这两种激素的平均水平无相关性，而其他研究则发现了正相关甚至强负相关。这些相互矛盾的结果可能部分归因于无法恰当地比较具有昼夜节律和超昼夜节律分泌模式的激素。我们的目的是研究血浆皮质醇节律特征随身高的可能差异，并比较皮质醇和GH的昼夜分泌情况。
我们分析了135名青春期前儿童的数据：（1）14名生长激素缺乏儿童；（2）36名身材矮小儿童（比同龄人平均身高低2 - 3个标准差）；（3）57名身材极矮小儿童（比同龄人平均身高低3 - 4个标准差）；以及（4）28名身高正常儿童（±2个标准差）组成的参考组。受试者在医院环境中生活，日间清醒（07:30 - 22:30），采样期间夜间休息，按固定时间食用医院常规饮食。
在一天中的大部分时间里，每隔约2 - 3小时采集一次血浆样本，在22:00至02:00之间每隔半小时采集一次样本，通过放射免疫分析法测定皮质醇和GH浓度。通过最小二乘法估计获得的昼夜节律特征在按性别和身高分组的组间进行参数检验比较。
所有研究组的皮质醇分泌均显示出具有统计学意义的昼夜节律（所有情况下P < 0.001）。昼夜节律参数比较表明，身材矮小、极矮小和正常的受试者之间具有相似特征。尽管非生长激素缺乏儿童与生长激素缺乏儿童在经节律调整的GH均值和幅度上存在边缘性统计学显著差异，但这两组之间的皮质醇分泌昼夜模式并无差异。在任何一组儿童中，GH和皮质醇的昼夜均值、幅度、平均值、标准差、标准误、最小值或最大值之间均未发现相关性。
GH与皮质醇之间的任何可能关系仍不明确。此外，生长激素缺乏儿童不一定具有高皮质醇血症或低皮质醇血症的特征。
