The assessment of adrenal function often involves comparing levels of a mineralocorticoid hormone with plasma renin activity or direct renin concentration. This comparison is particularly relevant in evaluating potential endocrine causes of hypertension. It is a key step in identifying primary aldosteronism, a condition where the adrenal glands produce excessive aldosterone independently of the renin-angiotensin system. The comparison is typically calculated by dividing the aldosterone concentration (usually expressed in ng/dL or pmol/L) by the renin activity (expressed in ng/mL/hr) or direct renin concentration (expressed in pg/mL). This calculated value helps clinicians determine if further diagnostic testing for primary aldosteronism is warranted.
This ratio is valuable because it helps differentiate between hypertension caused by primary aldosteronism and other forms of hypertension. Its use allows for targeted screening of individuals most likely to benefit from further investigation and treatment for primary aldosteronism. Prior to the widespread availability of this assessment, the diagnosis of primary aldosteronism was often missed, leading to potentially suboptimal management of hypertension and associated cardiovascular risks. Early diagnosis and treatment can improve blood pressure control and reduce the risk of cardiovascular complications.
