Simplification of the Oral Sodium Loading Test: 2-Day Method Replacing 3-Day Method.

Area of Science:

• Endocrinology
• Clinical Diagnostics
• Nephrology

Background:

• Primary aldosteronism (PA) is a common cause of secondary hypertension.
• The oral sodium loading test (OSLT) is a standard diagnostic tool for PA.
• The conventional OSLT requires 3 days, posing a challenge due to its time-consuming nature.

Purpose of the Study:

• To evaluate the efficacy of a 2-day OSLT protocol as a substitute for the traditional 3-day method.
• To determine if a shortened OSLT can provide comparable diagnostic accuracy for PA.

Main Methods:

• A prospective study involving PA patients and healthy controls.
• Participants underwent a 3-day oral high-sodium diet with daily sample collection.
• Fasting blood and 24-hour urine samples were analyzed on days 2 and 3 of the OSLT.

Main Results:

• No significant difference in 24-hour urinary aldosterone (UALD) was observed between day 2 and day 3 in either PA patients or healthy participants.
• Strong correlations (r=0.8322 and r=0.9333) were found for UALD between the second and third days.
• Aldosterone-related steroid hormone profiles showed no significant variations between the two testing days.

Conclusions:

• The 2-day OSLT method is a viable and effective alternative to the 3-day protocol.
• This shortened OSLT offers a more convenient diagnostic approach for primary aldosteronism.
• Implementing a 2-day OSLT can improve patient compliance and streamline the diagnostic process for PA.