Background: The 0.25mg short synacthen test (SST) is used to assess recovery from hypothalamic-pituitary-adrenal (HPA) suppression due to chronic glucocorticoid administration. We assessed the potential role of salivary cortisol and cortisone in predicting HPA function using the SST as the gold standard test.

Method: Between 09:00 and 10:30 salivary and blood samples were collected just prior to a SST to assess HPA axis recovery in patients previously treated with oral glucocorticoids. The cut-off for a normal SST was a 30-minute cortisol ≥450nmol/L.

Results: Fifty-six SSTs were performed on 47 patients. Of these, 15 were normal. The area under receiver operating characteristic (ROC) curves for serum cortisol, salivary cortisone and salivary cortisol were 0.772, 0.785 and 0.770 respectively. From the ROC analysis, the cut-offs for baseline serum cortisol (≥365nmol/L) and salivary cortisone (≥37.2nmol) predicted HPA axis recovery with 100% specificity in 26.7% of pass SSTs; whereas salivary cortisol predicted none. Baseline serum cortisol (≤170nmol/L), salivary cortisone (≤9.42nmol/L) and salivary cortisol (≤1.92nmol/L) predicted HPA suppression with 100% sensitivity in 58.5%, 53.7% and 51.2% of failed SSTs respectively. Using these cut-offs, baseline serum cortisol, salivary cortisone and salivary cortisol could reduce the need for SSTs by 50%, 46% and 37% respectively.

Conclusion: Although marginally inferior to early morning serum cortisol, early morning salivary cortisone may be used as a first-line test for assessing HPA function. We plan to incorporate salivary cortisone into a home based patient pathway to identify patients with HPA recovery, continuing HPA suppression and those who require a SST.

背景：0.25 mg短突触素试验（SST）用于评估由于长期服用糖皮质激素而引起的下丘脑-垂体-肾上腺（HPA）抑制的恢复情况。我们使用SST作为金标准测试评估了唾液皮质醇和可的松在预测HPA功能中的潜在作用。

方法：在SST之前的09:00至10:30之间收集唾液和血液样本，以评估先前接受口服糖皮质激素治疗的患者的HPA轴恢复。正常SST的临界值是30分钟的皮质醇– 450nmol / L。

结果：47例患者进行了56次SST。其中15例是正常的。血清皮质醇，唾液可的松和唾液皮质醇的接受者工作特征（ROC）曲线下面积分别为0.772、0.785和0.770。从ROC分析中，基线血清皮质醇（≥365nmol/ L）和唾液可的松（≥37.2nmol）的临界值预测HPA轴恢复，在26.7％的合格SST中具有100％的特异性；而唾液皮质醇无法预测。基线血清皮质醇（â170nmol/ L），唾液可的松（â9.42nmol/ L）和唾液皮质醇（â1.92nmol/ L）预测HPA抑制与58.5％，53.7中的100％敏感性％和51.2％的SST失败。使用这些临界值，基线血清皮质醇，唾液可的松和唾液皮质醇可以分别将对SST的需求减少50％，46％和37％。

结论：尽管清晨唾液可的松的疗效略低于清晨的血清皮质醇，但可以用作评估HPA功能的一线检查。我们计划将唾液可的松纳入家庭患者的治疗途径，以鉴定HPA恢复，持续HPA抑制和需要SST的患者。