You are here: Home :: Area NEM :: Medical science :: Human medicine

H. Alec Ross, Eric J. Meuleman, Fred C. G. J. Sweep

A simple method for estimating equilibrium constants for serum testosterone binding resulting in an optimal free testosterone index for use in elderly men

Keywords: dialysis, Equilibrium constant, free testosterone, sex hormone-binding globulin

An algorithm was developed to evaluate equilibrium constants for testosterone (Te) and sex hormone-binding globulin (SHBG) or albumin from serum free testosterone (FTe) measurements performed in a panel of 30 healthy elderly men by means of a near-reference method, i.e., symmetric dialysis (affinity constants: SHBG-Te, 1.13×10 ⁹ L/mol; albumin-Te, 4.4×10 ⁴ L/mol). Using these estimates, a free testosterone index (FTeI) was calculated from total Te and SHBG concentrations in a further 35 elderly men. This FTeI perfectly matches with actually measured free testosterone concentrations by symmetric dialysis in this second group, with a mean ratio index/measurement of 0.998±0.016 (SEM). The efficacy of the algorithm, which represents a simple alternative to previous cumbersome methods for estimation of equilibrium constants, is thereby demonstrated.

Clinical Chemical Laboratory Medicine, Walter de Gruyter

Print ISSN: 1434-6621
Volume: 43, 06/2005
Pages: 613 - 616

Show full article (external site)

Show all available items of this journal

 

Area NEM