A-112 A Consensus Reference Range for Ionized Magnesium

Abstract

Abstract Objective Ionized magnesium (iMg) is the physiologically active form of the analyte. Despite this, clinical adoption of iMg is infrequent, and there is only one commercially available analyzer that measures iMg. There are now numerous studies that have examined iMg levels in healthy individuals, and this report will summarize their findings and report a consensus reference range. Relevance Although reference ranges may vary based on population and location, among other factors, a baseline reference range is an important starting point to introducing a new test to any laboratory. Methods A literature search was performed using the search term “ionized magnesium”. Papers with reference ranges for healthy individuals measured by ion-selective electrodes were selected and an attempt was made to establish a reference range for adults and children. Results A total of 10 studies were identified, with 422 healthy individuals [1–10]. There were 322 adults and 100 children. Studies looked at venous samples and serum samples. Venous samples were anticoagulated with lithium heparin.Reference ranges for adults and children are shown below: To convert from mg/dL to mmol/L multiply by 0.41. To convert from mg/dL to MEq/L multiply by 1.22. Conclusions Although a large-scale study would be helpful in determining a more precise reference range, there is reasonably good agreement among studies evaluating iMg reference ranges in healthy adults and children. Further work to evaluate differences among different age groups, genders, and ethnic groups would be helpful to clinicians and researchers. There has been a call for updating reference ranges for total magnesium, as there is a wide variation in reported ranges [11].