作者：Cartaya J 等
美國哈佛醫學院麻薩諸塞州兒童總醫院兒童內分泌科
據《Endocr Pract》2015 年 2 月報導
原題：The Low Dose ACTH Stimulation Test: Is 30 Minutes Long Enough?
在診斷腎上腺功能不全時使用低劑量 ACTH 刺激試驗（LDST）是否合適，對試驗的結果應該如何解讀，在臨床中一直存在爭議。但是，現在很多醫學中心使用 LDST 來評估皮質醇分泌水平，有些僅根據 30 分鐘皮質醇水平來判斷腎上腺分泌功能正常還是不全。美國哈佛醫學院麻薩諸塞州兒童總醫院兒童內分泌科的 Cartaya J 等進行了一項研究，同時測量 30 分鐘和 60 分鐘的皮質醇水平，評估同時將兩個指標考慮在內是否會對試驗解讀產生影響。
這是一項回顧性單中心研究，回顧時間為 7 年，共有 82 例患者完成了 LDST 試驗，平均年齡為 11.7 歲，37% 為女性。檢測基線、使用替可克肽後 30 分鐘和 60 分鐘的皮質醇水平，≥18 μg/dL 則診斷為腎上腺功能正常。
結果顯示，54% 的患者在 60 分鐘時達到皮質醇分泌峰值，11 例患者未堅持到用藥後 30 分鐘。體重狀況是僅有的具有預測意義的特徵，超重和肥胖患者傾向於在 30 分鐘達到峰值，正常體重和低體重患者傾向於在 60 分鐘達到峰值。
研究表明，在進行低劑量 ACTH 刺激試驗時應該同時測量 30 分鐘和 60 分鐘的皮質醇水平，這可以避免對腎上腺功能不全的過度診斷。同時應該進行更多研究來證實本結果。
OBJECTIVE
Controversy persists regarding the use of the low dose ACTH stimulation test (LDST) for the diagnosis of adrenal insufficiency as well as the optimal interpretation of the results of the test. However, many centers are now using the LDST to assess adequacy of cortisol secretion, and some use only a 30 minute cortisol level to determine adrenal sufficiency or insufficiency. This study examined both a 30 and 60 minute cortisol level to assess whether the interpretation of the test was affected when both cortisol levels were taken into consideration.
DESIGN
Data were obtained by retrospective chart review from a single pediatric endocrinology unit over a 7 year period.
PATIENTS
82 patients who completed the LDST were identified. Patients had a mean age of 11.7 years; 37% were female.
MEASUREMENTS
Cortisol levels were evaluated at baseline, 30 and 60 minutes post administration of Cosyntropin. A cut off of ≥18 μg/dL was used to define adrenal sufficiency.
RESULTS
54% of patients reached peak cortisol levels at 60 minutes and 11 patients who did not pass the test at 30 minutes, did so at 60 minutes. The only predictive characteristic was weight status such that overweight and obese individuals tended to peak at 30 minutes and normal and underweight individuals tended to peak at 60 minutes.
CONCLUSIONS
Although further studies are necessary to confirm our findings, it appears that measuring cortisol both 30 and 60 minutes following administration of synthetic ACTH may be necessary to avoid overdiagnosis of adrenal insufficiency.