Annales de Biologie Clinique


What about bioavailable estradiol? Volume 66, issue 5, Septembre-Octobre 2008

Service de médecine nucléaire, CHU de Bordeaux, Hôpital Haut-Lévêque, Pessac

Estradiol (E 2) - similarly to testosterone - is a hormone mainly bound to SHBG and albumin in serum. Only the non SHBG-bound (free and albumin-bound hormone, i.e. bioavailable) hormone diffuses easily from circulation to tissues and is available for target cells. Bioavailable hormone measured or calculated seems to represent the best access to bioactive hormone concentration. Several studies reported that this bioavailable E 2 could be usefully measured for the understanding of chronic diseases in men or women, such as osteoporosis, cardiovascular disease and Alzheimer’s disease. E 2 assays require a high sensitivity to assess low concentrations. It is currently difficult to know if bioavailable E 2 is really implicated or not in a given pathology but its interest is reported in many epidemiological studies.