Christ-Crain Mirjam, Jutla Sukhdeep, Widmer Isabelle, Couppis Orestes, König Caroline, Pargger Hans, Puder Jardena, Edwards Ray, Müller Beat, Grossman Ashley B
Department of Endocrinology, Barts and The London, Queen Mary's School of Medicine, University of London, London, United Kingdom.
J Clin Endocrinol Metab. 2007 May;92(5):1729-35. doi: 10.1210/jc.2006-2361. Epub 2007 Mar 6.
Routinely available assays of adrenal function measure serum total cortisol (TC) and not the biologically active free cortisol (FC). However, there are few data on FC levels during surgical stress and in response to standard pharmacological tests.
Our objective was to evaluate TC and FC levels in different states of physical stress.
We conducted a prospective observational study in a university hospital.
We measured TC and FC levels in 64 patients: group A, 17 healthy controls without stress; group B, 23 medical patients with moderate stress; and group C, 24 surgical patients undergoing coronary bypass grafting. Cortisol levels in group C were measured basally and at several time points thereafter and were compared with responsivity to a pharmacological dose of ACTH. FC was measured using equilibrium dialysis.
In group C patients after extubation, the relative increase above basal FC was higher than the increase in TC levels (399 +/- 266 vs. 247 +/- 132% of initial values, respectively; mean +/- sd; P = 0.02) and then fell more markedly, FC levels falling to 67 +/- 49% and TC levels to 79 +/- 36% (P = 0.04). After ACTH stimulation, TC levels increased to 680 +/- 168 nmol/liter, which was similar to the increase with major stress (811 +/- 268 nmol/liter). In contrast, FC levels increased to 55 +/- 16 nmol/liter after ACTH stimulation but significantly greater with surgical stress to 108 +/- 56 nmol/liter (P < 0.001).
The more pronounced increase in FC seen during stress as compared with the ACTH test suggests that this test does not adequately anticipate the FC levels needed during severe stress.
常规可用的肾上腺功能检测方法测量的是血清总皮质醇（TC），而非具有生物活性的游离皮质醇（FC）。然而，关于手术应激期间及对标准药理试验反应时的FC水平的数据较少。
我们的目的是评估不同身体应激状态下的TC和FC水平。
我们在一家大学医院进行了一项前瞻性观察研究。
我们测量了64例患者的TC和FC水平：A组，17名无应激的健康对照者；B组，23名有中度应激的内科患者；C组，24名接受冠状动脉搭桥手术的外科患者。在C组患者中，于基础状态及此后的几个时间点测量皮质醇水平，并与对药理剂量促肾上腺皮质激素（ACTH）的反应性进行比较。使用平衡透析法测量FC。
C组患者拔管后，基础FC水平以上的相对升高高于TC水平的升高（分别为初始值的399±266%和247±132%；均值±标准差；P = 0.02），随后下降更为明显，FC水平降至67±49%，TC水平降至79±36%（P = 0.04）。ACTH刺激后，TC水平升至680±168 nmol/升，这与重大应激时的升高相似（811±268 nmol/升）。相比之下，ACTH刺激后FC水平升至55±16 nmol/升，但手术应激时显著更高，达到108±56 nmol/升（P < 0.001）。
与ACTH试验相比，应激期间FC的升高更为明显，这表明该试验不能充分预测严重应激期间所需的FC水平。
