Urinary clonidine suppression testing for the diagnosis of pheochromocytoma

Goupil, Remi, Fountoulakis, Stelios, Gordon, Richard D. and Stowasser, Michael (2015) Urinary clonidine suppression testing for the diagnosis of pheochromocytoma. Journal of Hypertension, 33 11: 2286-2293. doi:10.1097/HJH.0000000000000705

Author Goupil, Remi
Fountoulakis, Stelios
Gordon, Richard D.
Stowasser, Michael
Title Urinary clonidine suppression testing for the diagnosis of pheochromocytoma
Journal name Journal of Hypertension   Check publisher's open access policy
ISSN 1473-5598
Publication date 2015-11
Sub-type Article (original research)
DOI 10.1097/HJH.0000000000000705
Open Access Status Not Open Access
Volume 33
Issue 11
Start page 2286
End page 2293
Total pages 8
Place of publication London, United Kingdom
Publisher Lippincott Williams and Wilkins
Collection year 2016
Language eng
Formatted abstract
Objective:  The diagnosis of pheochromocytoma/paraganglioma (PPGL) involves detection of elevated levels of plasma and/or 24-h urine catecholamines and/or their metabolites, including metanephrines. Although these tests are reasonably sensitive, false-positive results are often encountered. Follow-up tests can provide additional information to correctly diagnose PPGL. In this regard, the utility of the urinary clonidine suppression test (UCST) remains unknown.

Methods:  To assess the diagnostic accuracy of the UCST in confirming or excluding PPGL, we conducted a retrospective analysis of all patients who underwent a UCST between 2000 and 2013 (n = 59; 15 PPGLs) at a single centre. Twelve-hour urine catecholamines and metanephrines were assessed before and after clonidine administration, and examined in relation to final diagnosis, PPGL or non-PPGL. Receiver operating characteristic analyses were used to identify optimal positivity cut-offs. Sensitivity, specificity, positive and negative predictive values were calculated.

Results:  Clonidine significantly decreased urine creatinine-corrected norepinephrine and normetanephrine in patients without PPGL (P < 0.001 pairwise) but not in patients with PPGL. Epinephrine and metanephrine levels were not significantly reduced in either group. Receiver operating characteristic (ROC) area under the curve was 0.955 [95% confidence interval (95% CI) 0.906–1.000, P < 0.001] and 0.823 (95% CI 0.706–0.940, P < 0.001) for norepinephrine and normetanephrine, respectively. Optimal cut-offs were established at 50 and 15% reductions in norepinephrine and normetanephrine, respectively, which provided high sensitivities (93.3% for both) and negative predictive values (97.4 and 96.3%). When both were concordant, higher diagnostic accuracy was achieved (100% sensitivity, 92.0% specificity). Results were similar in subgroups of individuals with borderline initial testing (n = 40) or on interfering drugs (n = 25).

Conclusion:  The UCST appears to be a highly accurate test for PPGL. Further prospective studies are needed to validate these results before routine use is encouraged.
Keyword Catecholamines
Clonidine suppression test
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
School of Medicine Publications
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