Reduction of calprotectin and phosphate during testosterone therapy in aging men: a randomized controlled trial

Objectives To investigate the effect of testosterone treatment on biomarkers calprotectin, fibroblast growth factor 23 (FGF23), soluble Klotho, phosphate, calcium, parathyroid hormone, creatinine and estimated glomerular filtration rate. Design Randomized, double-blinded, placebo-controlled study. Setting Odense Androgen Study—the effect of Testim and training in hypogonadal men. Participants Men aged 60–78 years old with a low normal concentration of free of bioavailable testosterone 94 cm recruited from 2008 to 2009 ( N = 48) by advertisement. Intervention Participants were randomized to receive 5–10 g gel/50–100 mg testosterone (Testim ® , Ipsen, France) or 5–10 g gel/placebo. Results The plasma levels of calprotectin and phosphate were significantly reduced in the group receiving testosterone therapy (gel) compared to the placebo group ( p