Aldosterone Renin Ratio (ARR)
Hormones marker
ARR
Aldosterone Renin Ratio (ARR)
Calculated ratio of aldosterone to renin used as the screening test for primary aldosteronism. The numeric value and its cutoff depend entirely on the units used for aldosterone and for renin.
PED Notes
This is the single most useful screen when an enhanced athlete has hypertension plus low or low-normal potassium. A raised ARR (high aldosterone relative to a suppressed renin) flags possible primary aldosteronism, a common and treatable driver of resistant high blood pressure. The ratio must be interpreted with posture, time of day, potassium status, and a review of interfering medications; a single abnormal ARR is a screen, not a diagnosis, and needs confirmatory testing.
When high
When HIGH (raised ARR):
- A raised ARR is a positive screen for primary aldosteronism and should trigger confirmatory testing (for example saline suppression) and, if confirmed, adrenal imaging under endocrinology
- In enhanced athletes this is a genuinely actionable finding: confirmed primary aldosteronism is treatable with mineralocorticoid receptor antagonists or, in unilateral disease, surgery, and treating it reduces cardiovascular and kidney risk
- Do not start treatment off a single ARR; false positives are common when potassium is low, posture is not standardised, or interfering drugs are on board
Practical notes:
- Correct hypokalaemia first; low potassium suppresses aldosterone and can mask a positive screen
- Standardise to a seated sample mid-morning after the patient has been up and about
- The ARR cutoff is lab and unit specific. A commonly cited threshold using aldosterone in ng/dL and PRA in ng/mL/h is about 20-30 (with aldosterone above roughly 15 ng/dL); thresholds differ when aldosterone is in pmol/L and renin is a direct concentration in mIU/L, so always use your lab's stated cutoff
When low
When LOW or NORMAL:
- A low or normal ARR makes primary aldosteronism unlikely and is the reassuring result
- It does not exclude other causes of hypertension; in enhanced athletes, AAS-driven sodium retention, erythrocytosis, sleep apnoea, and high training-stress sympathetic tone all raise blood pressure with a normal ARR
Clinical context:
- The ARR is a calculated value, so it is only as reliable as the aldosterone and renin that feed it; standardise collection for both
- Because the number depends on units, never compare an ARR across labs without checking the assay and units; interpret strictly against the reporting lab's cutoff
- Medication washout (where clinically safe) and potassium correction should be discussed with a clinician before screening
History Chart
Reading History
Frequently Asked Questions
Reference Ranges
Standard Range
VitalMetrics Range