Endocrine Abstracts

Introduction: Determination of serum (calculated) free testosterone (FT) in clinical practice has been suggested by several clinical guidelines for the diagnosis of male hypogonadism in men with borderline total T concentrations and in situations with altered sex hormone-binding globulin, as it correlates better with androgen exposure than total T. The gold-standard for the determination of FT levels is considered to be directly measured free testosterone (mFT) using equilibri...

Introduction: According to the free hormone transport hypothesis, only free testosterone (FT) is considered biologically active. Due to low circulating levels and technical challenges of direct FT measurements, calculators have been developed to estimate FT from serum total T, sex hormone-binding globulin (SHBG) and albumin levels. However, genetic polymorphisms altering SHBG’s binding affinity or capacity might result in calculation imprecisions with consequent incorrect...

Background: The treatment of metastatic castration-resistant prostate cancer (CRPC) remains dependent on Androgen Receptor (AR) mediated signalling, thus understanding all components involved in testosterone signalling in these men is of utmost importance. Recent studies have identified 11-ketotestosterone (11 KT) as a potent androgen receptor (AR) agonist present in humans. However, it is unknown if 11 KT is present at physiologically relevant concentrations in CRPC patients....