Bones and the sex hormones.

Sex hormones act in multiple ways to maintain a strong skeleton. In men, estrogen regulates cortical bone turnover, but testosterone maintains trabecular turnover. In normal men, sex hormone-binding protein is an independent risk factor for fractures. This led Aleksova and colleagues to measure the sex hormones and their binding protein in men receiving dialysis. Both higher sex hormone-binding globulin and higher total testosterone were associated with prevalent nonvertebral fractures, adding another layer of complexity to renal osteodystrophy.