Perton F T, Mijnhout G S, Kollen B J, Rondeel J M M, Franken A A M, Groeneveld P H P
Department of Internal Medicine, Isala, Zwolle, the Netherlands.
Neth J Med. 2017 Jan;75(1):14-20.
Clinical practice shows that many low-dose short synacthen tests (LD-SSTs) for diagnosing adrenal insufficiency in an outpatient setting have a normal outcome and could be considered superfluous. The objective of this study is to provide a guideline to safely reduce the number of unnecessarily performed LD-SSTs.
Data of LD-SSTs performed in outpatients were collected. Optimal morning cortisol cut-off values were determined using ROC analysis. Subsequently the predictive value of several variables was tested using univariable and multivariable logistic regression analyses.
A morning cortisol lower cut-off value of 145 nmol/l (specificity 89.9%, positive predictive value 90.0%) and an upper cut-off value of 375 nmol/l (sensitivity 100.0%, negative predictive value 100.0%) were found. Chronic fatigue symptoms and symptoms of hypotension or orthostasis as the main reason for performing the test predict a normal outcome. The use of glucocorticosteroids predicts an abnormal outcome of the LD-SST. Oral, topical, nasal and inhaled glucocorticosteroids are each significant predictors when analysed specifically for predicting central adrenal insufficiency.
By using morning cortisol cut-off values of 145 nmol/l and 375 nmol/l instead of the conventional cut-off values, the number of LD-SSTs performed in an outpatient setting can be reduced by 12%, while maintaining high sensitivity and specificity. Furthermore, the outcome of the LD-SST can be predicted by additional variables such as the indication for performing the test and the use of glucocorticosteroids. Different routes of administration of glucocorticosteroids such as inhalation or topical use should be taken into account when central insufficiency is suspected.
临床实践表明，许多在门诊环境中用于诊断肾上腺功能不全的低剂量短程促肾上腺皮质激素试验（LD-SSTs）结果正常，可能被认为是多余的。本研究的目的是提供一个指南，以安全地减少不必要进行的LD-SSTs的数量。
收集门诊患者进行LD-SSTs的数据。使用ROC分析确定最佳早晨皮质醇临界值。随后，使用单变量和多变量逻辑回归分析测试几个变量的预测价值。
发现早晨皮质醇下限临界值为145 nmol/l（特异性89.9%，阳性预测值90.0%），上限临界值为375 nmol/l（敏感性100.0%，阴性预测值100.0%）。慢性疲劳症状以及低血压或直立性低血压症状作为进行该试验的主要原因预示结果正常。使用糖皮质激素预示LD-SST结果异常。当专门分析预测中枢性肾上腺功能不全时，口服、局部、鼻用和吸入性糖皮质激素均为显著预测因素。
通过使用145 nmol/l和375 nmol/l的早晨皮质醇临界值而非传统临界值，门诊环境中进行的LD-SSTs数量可减少12%，同时保持高敏感性和特异性。此外，LD-SST的结果可通过其他变量预测，如进行试验的指征和糖皮质激素的使用。当怀疑中枢性功能不全时，应考虑糖皮质激素的不同给药途径，如吸入或局部使用。
