A proposed method for assessing plasma hypertonicity in vivo
J D Stookey1, M Burg, D E Sellmeyer
1Children's Hospital of Oakland Research Institute, Oakland, CA 94609, USA. jstookey@chori.org
European Journal of Clinical Nutrition
|July 21, 2006
Summary
A new index using mean corpuscular volume (MCV) differences can detect mild plasma hypertonicity. This method shows promise for identifying hypertonicity as a risk factor for obesity and chronic disease.
Area of Science:
- Physiology
- Clinical Chemistry
Background:
- Plasma hypertonicity is linked to obesity and chronic diseases.
- Existing measures for plasma hypertonicity may lack sensitivity for mild conditions.
Purpose of the Study:
- To propose and evaluate a novel index for detecting in vivo plasma hypertonicity.
- To assess the sensitivity of the new index compared to traditional measures.
Main Methods:
- A new index was developed comparing mean corpuscular volume (MCV) from automated cell counters (diluted) and manual calculations (non-diluted).
- Hypertonicity was induced in healthy men via fluid restriction after a water load.
- The new index's performance was evaluated against serum and urine indices and plasma vasopressin (PVP) levels.
Main Results:
- A difference of >2 fL between automated and manual MCV indicated in vivo hypertonicity.
- The novel MCV difference and PVP index detected hypertonicity in all participants.
- This new index proved more sensitive than traditional serum and urine indices.
Conclusions:
- The proposed MCV difference index offers a sensitive method for detecting mild in vivo plasma hypertonicity.
- This index has potential for identifying hypertonicity as a risk factor in obesity and chronic disease research.
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