DUBLIN — Measuring free testosterone together with total testosterone may provide a more accurate picture than measuring total-testosterone levels alone when it comes to diagnosing deficiency of this male hormone, a new study indicates.

There is concern that, under current clinical guidelines, some men are misdiagnosed with testosterone deficiency and receive inappropriate therapy, while others who should get treatment don't receive it, Dr Leen Antonio (University of Leuven, Belgium) explained when presenting her research here at the European Congress of Endocrinology (ECE) 2015.

"I think it would be preferable to use free testosterone rather than total testosterone to measure deficiency, especially in men who have borderline total-testosterone levels. Our results suggest that free testosterone is more informative than total testosterone," she told attendees.

Currently, total-testosterone levels are used as a measure of testosterone deficiency or hypogonadism. However, only free testosterone, unbound by sex-hormone–binding globulin (SHBG), can enter and activate androgen receptors in cells, resulting in testosterone-mediated effects, she explained.