Aldosterone - plasma

Last updated: Tuesday, 06, April, 2004

MBS Online Search Page: Click here for details

Item Process
Specimen

10 mL blood in chilled EDTA tube - plasma separated and frozen immediately.

Cessation of diuretics or antihypertensive drugs at least two weeks prior to testing is preferred.

Method

Immunoassay.

Peripheral venous (plasma) renin is usually assayed in conjunction with aldosterone. The aldosterone/renin ratio is calculated.

Reference Interval

Dependent on sodium intake, posture, drugs including ACE inhibitors and diuretics.

Application

Investigation of hypertension when primary hyperaldosteronism (Conn’s syndrome) is suspected, this is commonly but not invariably associated with hypokalaemia.

Documentation of hyperaldosteronism in the investigation of suspected renovascular hypertension.

Interpretation

The plasma aldosterone/renin ratio is of greater diagnostic value than either test alone.

A high aldosterone/renin ratio suggests a mineralo­corticoid abnormality.

Elevation of both aldosterone and renin to a similar extent suggests a renal abnormality. The result should be interpreted in consultation with the pathologist.

Reference

Veglio F et al. Minerva Med 2003; 94(4): 259-265.