Total red cell volume in healthy young males

Area of Science:

• Physiology
• Hematology
• Biostatistics

Background:

• Accurate estimation of total red cell volume (TRCV) is essential for clinical diagnosis and monitoring.
• Existing methods for expressing TRCV, such as milliliters per kilogram, are often unsatisfactory.
• Establishing reliable regression equations is key to defining normal physiological ranges.

Purpose of the Study:

• To develop and validate regression equations for predicting total red cell volume (TRCV) in normal adult males.
• To identify the most accurate predictor variables for TRCV.
• To provide a practical tool for clinical assessment of red cell volume.

Main Methods:

• Collected data from 79 normal male volunteer subjects.
• Performed regression analyses of TRCV against various anthropometric parameters including body weight, body surface area, and lean body mass.
• Evaluated regression models based on standard error of the estimate and correlation coefficients.
• Assessed reproducibility of TRCV measurements.

Main Results:

• Regression of TRCV on a combination of height and weight yielded the smallest standard error and largest correlation coefficient.
• The coefficient of variation for TRCV determination was 1.6% in repeated measurements.
• The commonly used ml/kg expression for TRCV was found to be unsatisfactory.
• A simplified graph for delineating normal from abnormal TRCV was developed.

Conclusions:

• Regression equations incorporating height and weight provide the most accurate prediction of TRCV.
• Body surface area is recommended as the independent variable for predicting normal TRCV ranges.
• The developed graphical tool can aid in clinical differentiation of normal and abnormal red cell volumes.