Butt Muhammad Imran, Alzuhayri Nouf, Amer Lama, Riazuddin Muhammad, Aljamei Hadeel, Khan Muhammad Sohaib, Abufarhaneh Mohammed, Alrajhi Eman, Alnassar Anhar, Alahmed Reem, Aljayar Dina Mahmoud Ahmad, Abothenain Fayha Farraj, De Vol Edward
King Faisal Specialist Hospital & Research Centre, Zahrawi St, Al Maather.
Al Faisal University, Al Zahrawi Street, Riyadh, Kingdom of Saudi Arabia.
Medicine (Baltimore). 2020 Oct 23;99(43):e22621. doi: 10.1097/MD.0000000000022621.
Short Synacthen test (SST) involves measuring the baseline, 30-, and 60-minute serum cortisol levels, after injecting 250 μg of synthetic adrenocorticotropic hormone or Synacthen (ACTH). This study aimed to review the current clinical practice of performing SST to establish a standardized test protocol and to additionally test the hypothesis regarding performing the 60-minute cortisol test alone and the dependence of overall SST result on baseline cortisol level.Patients >14 years who underwent SST from January 2010 to December 2017 were included. Pearson's chi-square cross-tabulation was used to identify individuals with inconsistent 30- and 60-minute serum cortisol test results. Logistic regression analysis was performed to predict normal responses based on the baseline cortisol value.Of the 965 patients identified from pharmacy, medical, and laboratory records, 849 were included. Mean baseline, 30-, and 60-minute cortisol levels after ACTH injection were 394 ± 286.58, 722 ± 327.11, and 827 ± 369.30 nmol/L, respectively. Overall, 715 (84%) and 134 (16%) patients had normal and abnormal responses, respectively. Primary and secondary adrenal insufficiency was diagnosed in 10% and 35%, respectively, while ACTH levels were not measured in 55% of the patients. Overall, 9.49% (n = 72) of the patients had a suboptimal response at 30 minutes, but reached the threshold value of 550 nmol/L at 60 minutes. This particular subgroup's mean change (240 nmol/L) in cortisol level from baseline to 30-minute was higher than that observed in patients with abnormal response at both time-points (mean change, 152 nmol/L). No patient with 30-minute optimal responses had 60-minute suboptimal responses. The baseline serum cortisol threshold of ≥226 nmol/L had 80% sensitivity, 71% specificity, and 93% positive predictive value for detecting a normal SST (P-value < .0001).Relying on a 60-minute cortisol level can identify all normal and abnormal responses, while relying on 30-minute cortisol level alone may produce false-positives. Additionally, a baseline cortisol level of ≥226 nmol/L is a reliable threshold for determining adequate adrenal function, particularly with a low pretest hypoadrenalism probability.
短促肾上腺皮质激素试验（SST）包括在注射250μg合成促肾上腺皮质激素或促肾上腺皮质激素（ACTH）后，测量基础值、30分钟和60分钟时的血清皮质醇水平。本研究旨在回顾目前进行SST的临床实践，以建立标准化的检测方案，并进一步验证仅进行60分钟皮质醇检测的假设以及SST总体结果对基础皮质醇水平的依赖性。纳入了2010年1月至2017年12月期间接受SST的14岁以上患者。采用Pearson卡方交叉表来识别30分钟和60分钟血清皮质醇检测结果不一致的个体。进行逻辑回归分析，以根据基础皮质醇值预测正常反应。从药房、医疗和实验室记录中确定的965例患者中，849例被纳入研究。注射ACTH后，基础值、30分钟和60分钟时皮质醇水平的平均值分别为394±286.58、722±327.11和827±369.30nmol/L。总体而言，715例（84%）患者反应正常，134例（16%）患者反应异常。原发性和继发性肾上腺皮质功能减退的诊断率分别为10%和35%，而55%的患者未检测ACTH水平。总体而言，9.49%（n = 72）的患者在30分钟时反应欠佳，但在60分钟时达到了550nmol/L的阈值。该特定亚组从基础值到30分钟时皮质醇水平的平均变化（240nmol/L）高于两个时间点反应异常患者的平均变化（152nmol/L）。30分钟反应最佳的患者在60分钟时均无反应欠佳的情况。基础血清皮质醇阈值≥226nmol/L对检测正常SST具有80%的敏感性（P值<0.0001）、71%的特异性和93%的阳性预测值。仅依靠60分钟时的皮质醇水平可以识别所有正常和异常反应，而仅依靠3～分钟时的皮质醇水平可能会产生假阳性结果。此外，基础皮质醇水平≥226nmol/L是确定肾上腺功能是否正常的可靠阈值，尤其是在检测前肾上腺皮质功能减退概率较低的情况下。
