Hypertension: primary hyperaldosteronism can be ruled out using biochemical tests

Clinical bottom line (level 4)

  1. 0.6% of patients attending a hypertension clinic had primary hyperaldosteronism. Biochemical tests can help rule this out (K > 4.0 mmol/L).
  2. Biochemical tests made primary hyperaldosteronism more likely, but further tests are required.
Massien-Simon et al: Presse Medicale 1995; 24 (27): 1238-1242
Expires October 2002

The study

Setting: hypertension clinic, acute hospital, France

159 patients (aged mean ~45, 52% female) : 60 with Conn's adenoma, 50 with primary hypertension and 49 normal controls

Non-independent unblinded reference standard, applied in some patients from a non-consecutive inappropriate spectrum.
Reference standard:
  • hypertension, potassium < 3.9 mmol/l, supine plasma aldosterone > 150 pg/ml, erect plasma renin < 15 pg/ml, unilateral adrenal tumour on CT, and lateralised secretion of aldosterone on adrenal vein catheterisation
Diagnostic test:
  • potassium
  • supine aldosterone
  • supine renin
  • supine aldosterone: renin ratio
  • erect aldosterone
  • erect renin
  • erect aldosterone: renin ratio

The evidence


diagnostic test primary hyperaldosteronism primary hypertension or normal LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
potassium < 4.0 mmol/l 58 4 24
(9.2 to 63) 		94% 0.035
(0.0089 to 0.14) 		0.021%
supine aldosterone > 179 pg/ml 55 24 3.8
(2.7 to 5.4) 		70% 0.11
(0.0047 to 0.26) 		0.066%
supine aldosterone: renin ratio > 22 42 4 17
(6.5 to 46) 		91% 0.31
(0.21 to 0.46) 		16%
erect aldosterone < 541 pg/ml 41 10 6.8
(3.7 to 13) 		80% 0.35
(0.24 to 0.51) 		18%
erect aldosterone: renin ratio > 29 43 14 5.1
(3.0 to 8.4) 		75% 0.33
(0.22 to 0.50) 		17%
erect renin < 26 pg/ml 50 55 1.5
(1.2 to 1.8) 		48% 0.38
(0.20 to 0.69) 		19%
total 60 99

Comments

  1. Primary hyperaldosteronism was a rare cause for hypertension. 68/11269 patients reviewed in this hypertension clinic had it (0.60%; 95% CI: 0.46% to 0.75%).
  2. Since the biochemical tests were used as part of the reference standard, the likelihood ratios are much better than in reality.

Citation

  1. Massien-Simon C, Battaglia C, Chatellier G, et al: Adenome de Conn: valeur diagnostique et pronostique de la mesure du potassium, de la renine, de l'aldosterone et du rapport aldosterone/renine. Presse Medicale 1995; 24 (27): 1238-1242
Contributor: Chris Ball and Clare Wotton, October 1999
Reviewer:

Clinical Question.
Patient hypertension
Intervention or Exposure biochemical tests: potassium, aldosterone, renin
Outcome primary hyperaldosteronism, Conn's adenoma