Rasmussen M H, Hvidberg A, Juul A, Main K M, Gotfredsen A, Skakkebaek N E, Hilsted J, Skakkebae N E
Department of Internal Medicine and Endocrinology, Hvidovre University Hospital, Denmark.
J Clin Endocrinol Metab. 1995 Apr;80(4):1407-15. doi: 10.1210/jcem.80.4.7536210.
In the present study, we 1) determined whether the impaired spontaneous 24-h GH secretion as well as the blunted GH response to provocative testing in obese subjects are persistent disorders or transient defects reversed with weight loss and 2) investigated 24-h urinary GH excretion and basal levels of insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP-3), as well as insulin in obese subjects before and after a massive weight loss. We studied 18 obese subjects (age, 26 +/- 1 yr; body mass index, 40.9 +/- 1.1 kg/m2); 18 normal age-, and sex-matched control subjects; and 9 reduced weight obese subjects after a diet-induced average weight loss of 30.3 +/- 4.6 kg. Twenty-four-hour spontaneous GH secretion was estimated by obtaining 3240 integrated 20-min blood samples using a constant blood withdrawal technique and computerized algorithms. Body composition was determined using anthropometric measurements and dual energy x-ray absorptiometry scanning (DXA). In the obese subjects, 24-h spontaneous GH release profiles and the GH responses to insulin-induced hypoglycemia and L-arginine as well as basal IGF-I levels and the IGF-I/IGFBP-3 molar ratio were decreased, whereas insulin levels were elevated compared to those in normal subjects. In obese subjects, 24-h spontaneous GH secretion and serum IGF-I levels were inversely related to abdominal fat (r = -0.67; P < 0.01) and percent body fat (r = -0.69; P < 0.01), respectively. The decreased 24-h spontaneous GH release profiles, the decreased GH responses to insulin-induced hypoglycemia and L-arginine, the decreased basal IGF-I levels and IGF-I/IGFBP-3 molar ratio, as well as the elevated insulin levels were returned to normal after a massive weight loss in the obese subjects. In conclusion, the present study has shown reversible defects in 24-h spontaneous GH release profiles, basal IGF-I levels, and the IGF-I/IGFBP-3 molar ratio in obese subjects. The recovery of the 24-h GH release points to an acquired transient defect rather than a persistent preexisting disorder.
在本研究中，我们：1）确定肥胖受试者中24小时自发性生长激素（GH）分泌受损以及GH对激发试验反应减弱是持续性疾病还是随体重减轻而逆转的短暂缺陷；2）调查了大量体重减轻前后肥胖受试者的24小时尿GH排泄以及胰岛素样生长因子-I（IGF-I）、IGF结合蛋白-3（IGFBP-3）和胰岛素的基础水平。我们研究了18名肥胖受试者（年龄26±1岁；体重指数40.9±1.1kg/m²）；18名年龄和性别匹配的正常对照受试者；以及9名通过饮食诱导平均体重减轻30.3±4.6kg的体重减轻的肥胖受试者。使用恒速采血技术和计算机算法获取3240份20分钟的整合血样，以估计24小时自发性GH分泌。通过人体测量和双能X线吸收法扫描（DXA）确定身体成分。肥胖受试者中相较于正常受试者，24小时自发性GH释放曲线、GH对胰岛素诱导的低血糖和L-精氨酸的反应以及基础IGF-I水平和IGF-I/IGFBP-3摩尔比降低，而胰岛素水平升高。在肥胖受试者中，24小时自发性GH分泌和血清IGF-I水平分别与腹部脂肪（r = -0.67；P < 0.01）和体脂百分比（r = -0.69；P < 0.01）呈负相关。肥胖受试者在大量体重减轻后，24小时自发性GH释放曲线降低、GH对胰岛素诱导的低血糖和L-精氨酸的反应降低、基础IGF-I水平和IGF-I/IGFBP-3摩尔比降低以及胰岛素水平升高均恢复正常。总之，本研究表明肥胖受试者在24小时自发性GH释放曲线、基础IGF-I水平和IGF-I/IGFBP-3摩尔比方面存在可逆缺陷。24小时GH释放的恢复表明是获得性短暂缺陷而非持续性既往疾病。
