Hypertension: primary aldosteronism could rarely occur without hypokalaemia

Clinical bottom line (level 4)

  1. 3% of normokalaemia patients previously diagnosed with essential hypertension had primary aldosteronism.
Brown et al: Australian and New Zealand Journal of Medicine 1996; 26: 533-538
Expires October 2003

The study

Setting: hypertension clinic, Australia

74 patients (aged ?: 40% aged 40 to 60, ?% male) with essential hypertension and normokalaemia (previously investigated for secondary hypertension if considered on clinical grounds)

Excluded if
  • blood pressure too poorly controlled to alter
  • pregnancy
  • inability to obtain blood easily


    • All hypertensives medications were ceased for three days prior to study.
    Independent blinded reference standard, applied in all patients from a non-consecutive inappropriate spectrum.
    Reference standard:
    • inadequate aldosterone suppression following saline loading and fludrocortisone

    The evidence

    pre-test probability of primary aldosteronism: 2.7%, (95% CI: 0.3% to 9.4%)

    Citation

    1. Brown MA, Zammit VC, Cramp HA, et al: primary hyperaldosteronism: a missed diagnosis in 'essential hypertensives'?. Australian and New Zealand Journal of Medicine 1996; 26: 533-538
    Search Terms: aldosteron* and diagnos* in Cochrane
    Contributor: Chris Ball and Clare Wotton, October 1999
    Reviewer:

    Clinical Question.
    Patient essential hypertension
    Intervention or Exposure normokalaemia
    Outcome Conn's syndrome; hyperaldosteronism