Endocrine Abstracts

Global knockout models of the androgen receptor (ARKO) illustrates the many roles androgens and their receptor have in the development of male reproductive organs and the gender differences in many features like the musculoskeletal system. However, neither the global ARKO nor orchidectomy models discriminate between direct and indirect effects of androgens. To determine direct and indirect effects of androgens on muscle, we developed a muscle-specific ARKO (called satARKO for ...

It is well established that sex steroid deficiency induces bone loss, resulting in osteoporosis. Consequently, global androgen receptor knock out (ARKO) mice have trabecular and cortical osteopenia. Bone cell-specific ARKOs however, have a much less pronounced bone phenotype, suggesting that androgens have an influence on processes in other systems or organs which in turn have an impact on bone metabolism. The kidney is a likely candidate, as it plays an important role in calc...

Objective: Long-term androgen deprivation therapy (ADT) negatively influences bone. The short-term effects on bone and mineral homeostasis are less known. Therefore, we aimed to investigate the early effects of ADT on calcium/phosphate homeostasis and bone turnover.Design: Prospective cohort study.Methods: Eugonadal adult male sex offenders, who were referred for ADT to the endocrine outpatient clinic, received cyproterone acetate....

Sex hormone-binding globulin (SHBG) is a high-affinity binding protein for androgens and estrogens. According to the “free hormone hypothesis”, SHBG regulates the free sex steroid fraction and restricts androgen bioactivity. SHBG has also been independently associated with diabetes, osteoporosis etc., but whether this represents causality or residual confounding remains unconfirmed. We studied mice overexpressing human SHBG. Using multiligand liquid chromatography ta...

Background: During ageing, total testosterone (TT) declines and SHBG increases, resulting in a greater decline of free testosterone (FT) compared to TT. However, guidelines suggest using TT to diagnose androgen deficiency and to reserve FT only for men with borderline TT. We investigated if isolated low FT or isolated low TT was associated with androgen-related endpoints in healthy men.Methods: 3369 community-dwelling men, aged 40–79, were included....