Popot M A, Houghton E, Ginn A, Jones M, Teale P, Samuels T, Lassourd V, Dunnett N, Cowan D A, Bonnaire Y, Toutain P L
L.A.B. 169, Chatenay Malabry, France.
Equine Vet J. 1997 May;29(3):226-9. doi: 10.1111/j.2042-3306.1997.tb01673.x.
The purpose of the present report was to estimate the population parameters of cortisol concentrations in urine, an endogenous hormone used as a 'doping' agent and for which an international threshold (1.0 micrograms/ml) has been proposed. Two data bases (French and UK) corresponding to 112 and 142 samples, respectively were considered. Urine was collected under specific post competition conditions. Cortisol concentrations were obtained by validated methods (HPLC for the French samples, and GC-MS for UK samples). No difference was observed between the 2 data sets and statistical analyses were carried out on the two merged files. The overall geometric mean cortisol concentration was 48 ng/ml. Distribution was not Gaussian. A log-normal distribution was not rejected (for P > 0.05). Using the log-normal distribution, it was calculated that the probability of exceeding a cortisol concentration in urine of 1.0 micrograms/ml was 1.1 x 10(-4). It was concluded that the actual international threshold is specific i.e. robust with regard to the risk of erroneously declaring an unmedicated horse as positive.
本报告的目的是估算尿中皮质醇浓度的总体参数。皮质醇是一种用作“兴奋剂”的内源性激素，并且已提出了国际阈值（1.0微克/毫升）。考虑了分别对应112个和142个样本的两个数据库（法国和英国的）。尿液是在特定的赛后条件下收集的。皮质醇浓度通过经过验证的方法获得（法国样本采用高效液相色谱法，英国样本采用气相色谱 - 质谱法）。在两个数据集之间未观察到差异，并对两个合并文件进行了统计分析。皮质醇浓度的总体几何平均值为48纳克/毫升。分布不是高斯分布。未排除对数正态分布（P>0.05）。使用对数正态分布计算得出，尿中皮质醇浓度超过1.0微克/毫升的概率为1.1×10^(-4)。得出的结论是，实际的国际阈值是特定的，即在错误地将未用药的马匹判定为阳性的风险方面是稳健的。
