Measurement of free fraction, totalconcentration and protein binding fortestosterone, triiodothyronine and thyroxine: supplementary data

Aims: Measuring the total and free concentrations of hormones is useful, but the technology to dothis simultaneously is lacking. Methods: A new method offers the ability to measure these parametersconcurrently for testosterone, thyroxine and triiodothyronine. Results: The free concentrations showedsignificant correlations with patients’ vital statistics. Overall, 67% of correlations for total concentrationshowed that the new and classical methods had equal accuracy, or that comprehensive ultrafiltration wasmore accurate. The protein binding term was found to correlate significantlywith the patients’ luteinizinghormone, prostate-specific antigen and height. Conclusion: Comprehensive ultrafiltration for measuringthe total concentration, free concentration and protein binding term uses less sample and is much fasterthan measuring these parameters with three separate methods.