Renin Activity, Plasma
Reference Lab
Lavender (EDTA)
Pink (EDTA)
Pearl (EDTA)
In order to facilitate interpretation of test results, the patient should be taken off medications for at least three weeks prior to sample collection (see Limitations for details). Dietary sodium levels during the period prior to testing can affect renin levels. Sodium restriction tends to cause an increase in renin activity, while supplementation can result in lower values. A 24-hour urine sodium determination from a sample collected on the day before a renin test can be used to assess sodium intake.
Since patient posture prior to collection affects renin levels, it is recommended that the patient be ambulatory for at least 30 minutes before blood collection.1 If inpatients are physically able, they should be asked to ambulate for 30 minutes before blood is drawn for renin activity.
The patient's posture at the time of collection should be noted. Keep tube at room temperature. Centrifuge at room temperature.1 Transfer the plasma into a LabCorp PP transpak frozen purple tube with screw cap (LabCorp N° 49482). Freeze immediately and maintain frozen until tested. It is critical that the plasma be transferred and frozen as quickly as possible to prevent cryoactivation of protein to renin (which results in falsely elevated renin levels).