Munro Vicki, Elnenaei Manal, Doucette Steve, Clarke David B, Imran Syed Ali
Division of Endocrinology, Department of Medicine, Dalhousie University, Saint John, NB, Canada.
Division of Clinical Chemistry, Department of Pathology and Laboratory Medicine, Dalhousie University, Halifax, NS, Canada.
Clin Biochem. 2018 Apr;54:37-41. doi: 10.1016/j.clinbiochem.2018.02.010. Epub 2018 Feb 16.
Despite widespread use of the 250-mcg Cosyntropin test (ACTH test) for the diagnosis of adrenal insufficiency (AI), the effect of time of day and the utility of performing both 30- and 60-min serum cortisol values remains unclear.
We conducted a retrospective cohort study of all ACTH testing at the Halifax Neuropituitary Program, Nova Scotia, Canada between January 2006 and April 2016. Data were collected on age, gender, medication history, serum cortisol levels at 0, 30 and 60 min after ACTH administration, as well as time of and indication for testing.
There were 336 tests performed, divided by time of day (0800-1000 h, 1001-1200 h, and after 1200 h). There were no differences in mean cortisol levels at 30 (574.5, 559, 534 nmol/L, respectively; p = 0.25) and 60 min (642, 623, 619 nmol/L, respectively; p = 0.63) between groups. When comparing 30- vs. 60-min values using a cut-off of ≥500 nmol/L, 45 patients (13.4%) failed to reach the cut-off at 30 min but met the cut-off at 60 min. Conversely, only 2 patients (0.6%) who met the cut-off at 30 min failed to reach it at 60 min.
We found that outcomes from ACTH testing are not affected by time of day. Furthermore, using a 30-min cortisol level in isolation results in more than one in seven patients having a false positive diagnosis of AI; a 60-min value of ≥500 nmol/L alone may be sufficient to diagnose AI in >99% of cases.
尽管250微克促肾上腺皮质激素试验（ACTH试验）广泛用于诊断肾上腺皮质功能不全（AI），但一天中不同时间的影响以及同时检测30分钟和60分钟血清皮质醇值的效用仍不明确。
我们对2006年1月至2016年4月在加拿大新斯科舍省哈利法克斯神经垂体项目进行的所有ACTH检测进行了一项回顾性队列研究。收集了年龄、性别、用药史、ACTH给药后0、30和60分钟时的血清皮质醇水平，以及检测时间和检测指征的数据。
共进行了336次检测，按一天中的时间（08:00 - 10:00、10:01 - 12:00以及12:00之后）进行划分。各组在30分钟时的平均皮质醇水平（分别为574.5、559、534纳摩尔/升；p = 0.25）和60分钟时的平均皮质醇水平（分别为642、623、619纳摩尔/升；p = 0.63）无差异。当使用≥500纳摩尔/升的临界值比较30分钟和60分钟的值时，45例患者（13.4%）在30分钟时未达到临界值，但在60分钟时达到了临界值。相反，在30分钟时达到临界值的患者中，只有2例（0.6%）在60分钟时未达到临界值。
我们发现ACTH检测结果不受一天中时间的影响。此外，单独使用30分钟时的皮质醇水平会导致超过七分之一的患者被误诊为AI；仅60分钟时的值≥500纳摩尔/升可能足以在超过99%的病例中诊断AI。
