Although 5∼10% of hypertension is caused by primary aldosteronism (PA), it is difficult to diagnose PA from essential hypertension (EH). Considering the cost and technical difficulty, some institutes perform adrenal venous sampling (AVS) in all PA patients, and others advocated its selective use. The Japanese Society of Hypertension (JSH) recommends screening young hypertensive patients, but there are no special diagnostic guidelines for younger patients.Design and Method:
So we analyzed retrospectively 47 young (=<40, mean: 33.7y) hypertensive patients (BP 132/87 mmHg, 0.9 oral medication, potassium supplementation: 11%, PAC: 227 pg/mL). PA (12 men and 17 women) were diagnosed by the guideline of JSH, that is, after screening by aldosterone to renin ratio (ARR), PA was diagnosed by confirmatory tests.Results:
By upright furosemide-loading test (UFT), 95% of PA and 38% of EH were positive, while captopril challenge test (CCT), 75% (PA), 24% (EH) and sodium infusion test (SIT), 83%(PA), 36%(EH). About 38% of PA were positive in three confirmatory tests. All patients diagnosed as PA underwent thin-sliced CT and AVS (excluding one). Hypersecretion were decided by the criteria of Japanese Endocrine Society (Endocr J. 2011) and 93% cases were classified as unilateral (11 cases) or bilateral (14 cases) disease by single AVS and the concordance between CT and AVS was 96% (100% under 35y).Conclusions:
Despite the relative low salt sensitivity of the young, ARR was most appropriate for screening PA. No single confirmatory test was absolute in the definitive diagnosis of young PA. Although the sensitivity of UFT was better than those of CCT and SIT, the cessation during UFT was rather high (16%) and several tests should be combined not to overlook young PA. All PA patients should be advised to undergo AVS for identifying the correct side of the lesion before surgery, but in some limited cases, treatment without AVS may be justified.