Related Experiment Videos
Variability within individuals of plasma ionic magnesium concentrations.
Ian J Newhouse1, Kris P Johnson, William J Montelpare
1School of Kinesiology, Lakehead University, Thunder Bay, Ontario, Canada. Ian.Newhouse@Lakeheadu.ca
BMC Physiology
|April 30, 2002
Summary
Ionic magnesium (iMg) levels show significant within-day variability, suggesting a potential circadian rhythm. Clinicians should interpret single iMg measurements cautiously due to this biological fluctuation.
Area of Science:
- Clinical Chemistry
- Biomarkers
- Physiology
Background:
- Ionic magnesium (iMg) is the biologically active form, commonly measured using ion-selective electrodes (ISE).
- Existing evidence suggests substantial within-subject variability in iMg levels.
Purpose of the Study:
- To investigate the extent and patterns of within-subject variability in ionic magnesium (iMg) measurements.
- To determine if iMg exhibits significant diurnal or between-day fluctuations.
Main Methods:
- Analysis of individual iMg ranges and coefficients of variation (CV).
- Comparison of biological variability to analytical variation.
- Assessment of within-day and between-day iMg variations using statistical analysis.
Main Results:
- Biological variability accounted for nearly half of the total iMg variation (mean CV 4% vs. analytical variation 2.3%).
- Significant within-day iMg variations were observed between 7:00-10:00 and 10:00-22:00 (p <.001).
- No significant between-day variations in iMg levels were detected (p =.56).
Conclusions:
- The observed within-day variability suggests a potential circadian rhythm for iMg.
- Single iMg measurements require cautious interpretation pending further research into iMg variability.