Survey of renin and aldosterone testing practices by Ontario laboratories – Providing insight into best practices

Abstract

Objectives Testing for renin and aldosterone in clinical laboratories is complicated by pre-analytical considerations such as the posture for blood collection and susceptibility to cryoactivation of renin. From an analytical perspective, there are both renin activity and renin mass or concentration assays available. There can also be variability in result reporting practices and the aldosterone-renin ratio (ARR) cut-off applied to screen for primary aldosteronism (PA). The Institute for Quality Management in Healthcare (IQMH) Centre for Proficiency Testing surveyed laboratories on their handling of renin and aldosterone testing to better understand current practices. Design and methods An online survey was prepared and sent to 134 Canadian laboratories enrolled in endocrinology proficiency testing with IQMH. Results One hundred twenty Ontario laboratories submitted responses. While only six (5%) laboratories perform testing for both renin and aldosterone, 108 (90%) collect and process specimens to be tested by reference laboratories. The survey revealed considerable variation in practices including the recommended state of patients prior to sample collection (for example, regarding medications or salt intake), the patient posture specifications for sample collection, the precautions taken against cryoactivation of renin, the choice of renin activity or mass assay, and the ARR cut-off used. The available literature on these factors was then reviewed. Conclusions Although there is no standardized procedure for specimen collection, analysis, or result reporting for renin or aldosterone testing, we have attempted to summarize the available literature to develop evidence-based recommendations. Where laboratory practice differs from peers and/or recommended protocols, laboratories should review their practices.

Development of a designed comparison method based on isotope dilution liquid chromatography–tandem mass spectrometry for determining plasma renin activity and its clinical assessment of renin activity stability in plasma

“…This variation is probably attributed to the ex vivo renin catalysis activity or prorenin cryoactivation. 6 Prorenin cryoactivation was expected to occur aer the cooling stimulation lasting at least 6 h to 24 h, 24,29 which is similar to our ndings. This study provided more exibility and convenience to laboratory technicians, especially when handling the EQA plasma materials.…”

Exercise-Induced Fluid Retention, Cardiac Volume Overload, and Peripheral Edema in Ultra-Distance Cyclists

“…Separate analysis of serum renin and aldosterone were not performed because adequate preanalytical procedures (resting in a seated position for 30 minutes before blood collection) were not feasible in the study setting. 37 Considering that signs of fluid retention were still increasing on postride analysis (day 6) and recovery was not completed (e.g., end-diastolic volume of the right ventricle), a longer study period and later recovery analysis would be an interesting setting for follow-up studies.…”