1. What is the Renin Aldosterone Ratio?

The Renin Aldosterone Ratio (RAR) is a diagnostic tool used to evaluate patients with suspected primary aldosteronism, a condition characterized by excessive aldosterone production. It helps differentiate between various forms of hypertension.

2. How Does the Calculator Work?

The calculator uses the RAR formula:

Where:

• \( A \) — Aldosterone concentration (pg/mL)
• \( R \) — Renin activity (ng/mL/hr)

Explanation: The ratio compares the level of aldosterone to renin activity in the blood, with higher ratios suggesting possible primary aldosteronism.

3. Importance of RAR Calculation

Details: RAR is a key screening test for primary aldosteronism, which is a potentially curable cause of hypertension. Early detection can lead to targeted treatment and better blood pressure control.

4. Using the Calculator

Tips: Enter aldosterone in pg/mL and renin activity in ng/mL/hr. Both values must be greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal RAR value?
A: Typically, a ratio below 20 is considered normal. Values above 20-30 may suggest primary aldosteronism and require further testing.

Q2: When should RAR testing be performed?
A: It's recommended for patients with resistant hypertension, spontaneous hypokalemia, or early-onset hypertension.

Q3: Are there any medication considerations before testing?
A: Yes, certain antihypertensive medications can affect results. Patients should consult their physician about potential medication adjustments before testing.

Q4: What are the limitations of RAR testing?
A: False positives can occur with renal impairment, and false negatives may happen with sodium restriction. Confirmatory testing is usually needed.

Q5: How should patients prepare for RAR testing?
A: Ideally, patients should be upright for at least 2 hours before blood draw, and samples should be collected in the morning.