Nieves-Rivera F, Rogol A D, Veldhuis J D, Branscom D K, Martha P M, Clarke W L
Department of Pediatrics, University of Virginia, Charlottesville 22908.
J Clin Endocrinol Metab. 1993 Sep;77(3):638-43. doi: 10.1210/jcem.77.3.8370685.
At puberty, elevated circulating GH concentrations are found, with a parallel increase in the levels of insulin-like growth factor-I (IGF-I). However, these hormonal changes are less well understood in children with insulin-dependent diabetes mellitus (IDDM) during the peripubertal years. Since the metabolic derangement is often associated with elevated circulating GH and diminished serum IGF-I levels, we sought to determine whether similar alterations occur in boys with IDDM. A multiple parameter deconvolution analysis was applied to serum GH concentrations measured at 20-min intervals for 24 h in 25 boys with IDDM. Subjects were divided into 3 pubertal groups, pre (n = 9), early (n = 8), and late (n = 11), according to Tanner stage. Glycosylated hemoglobin and body mass index-SD scores were indistinguishable among groups. Forty nondiabetic peripubertal boys served as controls. Similar to those in the normal boys, circulating GH concentrations and serum IGF-I levels increased during puberty in the boys with IDDM. The augmented circulating GH concentrations occur due to an increase in GH secretion, as determined by calculated daily GH production rates (760 +/- 119 vs. 1025 +/- 121 vs. 1821 +/- 266 micrograms/day, respectively for the 3 groups). IGF-I levels were decreased in prepuberty in the boys with IDDM and were overcome with increasing pubertal development (0.68 +/- 0.13 vs. 0.78 +/- 0.11 vs. 1.53 +/- 0.20 U/mL; P < 0.05). There was an increase in the maximal rate of GH secretion per burst (amplitude) during prepuberty (0.54 +/- 0.05 vs. 0.88 +/- 0.17 microgram/L.min, control vs. IDDM; P = 0.03) and early puberty (0.64 +/- 0.10 vs. 0.88 +/- 0.10 microgram/L.min; p = 0.04). The differences in amplitude between the controls and the boys with IDDM were absent once puberty was well established (1.00 +/- 0.10 vs. 1.02 +/- 0.14 microgram/L.min; P > 0.05). The metabolic clearance of GH was increased in the late pubertal boys with IDDM compared to that in their controls (GH half-life, 24.0 +/- 1.0 in control vs. 19.8 +/- 0.5 min in diabetics; P = 0.006). We conclude that comparable increments in GH secretion and serum IGF-I levels in boys with IDDM in moderate glycemic control and controls are presumably related to increased levels of testosterone in both groups. However, differences exist with respect to GH secretory burst amplitude (augmented) and serum IGF-I concentrations (decreased) before puberty is reached. These alterations disappear with the establishment of puberty.
在青春期，循环中的生长激素（GH）浓度升高，胰岛素样生长因子-I（IGF-I）水平也相应增加。然而，在青春期前后患有胰岛素依赖型糖尿病（IDDM）的儿童中，这些激素变化的情况尚不太清楚。由于代谢紊乱常与循环中GH升高和血清IGF-I水平降低有关，我们试图确定患有IDDM的男孩是否也会出现类似变化。对25名患有IDDM的男孩进行了24小时的血清GH浓度测定，每隔20分钟测量一次，并应用多参数反卷积分析。根据坦纳分期，将受试者分为3个青春期组：青春期前（n = 9）、青春期早期（n = 8）和青春期晚期（n = 11）。糖化血红蛋白和体重指数标准差得分在各组之间无显著差异。40名青春期前后的非糖尿病男孩作为对照。与正常男孩相似，患有IDDM的男孩在青春期时循环中的GH浓度和血清IGF-I水平也会升高。循环中GH浓度的增加是由于GH分泌增加所致，通过计算每日GH产生率可知（3组分别为760±119、1025±121和1821±266微克/天）。患有IDDM的男孩在青春期前IGF-I水平降低，随着青春期发育的进展而得到改善（分别为0.68±0.13、0.78±0.11和1.53±0.20 U/mL；P < 0.05）。青春期前GH分泌的最大速率（幅度）有所增加（对照组与IDDM组分别为0.54±0.05和0.88±0.17微克/升·分钟；P = 0.03），青春期早期也有增加（分别为0.64±0.10和0.88±0.10微克/升·分钟；P = 0.04）。一旦青春期完全确立，对照组与患有IDDM的男孩之间在幅度上的差异就消失了（分别为1.00±0.10和1.02±0.14微克/升·分钟；P > 0.05）。与对照组相比，患有IDDM的青春期晚期男孩的GH代谢清除率增加（GH半衰期，对照组为24.0±1.0分钟，糖尿病患者为19.8±0.5分钟；P = 0.006）。我们得出结论，血糖控制良好的患有IDDM的男孩与对照组在GH分泌和血清IGF-I水平上的可比增加可能与两组中睾酮水平的升高有关。然而，在青春期达到之前，GH分泌脉冲幅度（增加）和血清IGF-I浓度（降低）方面存在差异。随着青春期的确立，这些变化消失。
