Session: MON 723-757-Renin-Angiotensin-Aldosterone System/Endocrine Hypertension
Bench to Bedside
Poster Board MON-731
Aims of the study were to investigate 1) the diagnostic criteria for subtype classification and 2) whether SIT is reliable when carried out with a shorter infusion period.
Subjects and methods: Forty three patients with PA were studied. Twenty eight were diagnosed as bilateral PA (Bil-PA) and 15 were diagnosed as unilateral PA (Unil-PA) by CT, adrenal venous sampling and histopathological analysis after surgery. SIT was performed by infusing 2 liters of saline over 4 hrs. Blood samples for PAC were obtained at 2hrs (PAC2h) and 4hrs (PAC4h). Distinguishing Unil-PA from Bil-PA criteria of SIT were assessed using ROC curve analysis.
Results: PAC2h and PAC4h in patients with Unil-PA were significantly higher than those with Bil-PA (289±114 vs. 88±44 pg/ml; 301±132 vs. 72±31pg/m) (p<0.01). Using the ROC curve analysis, the optimal cutoff value of PAC2hr for distinguishing Unil-PA from Bil-PA was 120pg/ml (sensitivity 100%, specificity 85.7%) and that of PAC4h was 135pg/ml (sensitivity 93.3%, specificity 96.4%). AUC of both of them were not significantly different (0.971 for PAC2h vs. 0.974 for PAC4h).
Conclusions: The SIT is useful for subtype classification of PA. In addition, the test can be shortened to 1litter infusion of saline over 2hrs with 120pg/ml as the best cutoff limit. The present study therefore suggest that short-term SIT could be used as confirmatory and subtype testing.
Nothing to Disclose: MT, KN, AT, KN, RN, MK, YU, TU, TT, AS, AT, MN
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