Androgenic-anabolic steroid effects on serum thyroid, pituitary and steroid hormones in athletes.

Endocrine responses in seven power athletes were investigated during a 12 week strength training period, when the athletes were taking high doses of androgenic-anabolic steroids, and during the 13 weeks following drug withdrawal. During the use of steroids significant decreases (P less than 0.05 to 0.001) in the serum concentrations of thyroid stimulating hormone, thyroxine, triidothyronine, free thyroxine, and thyroid hormone-binding globulin (TBG) were found, whereas the value of triidothyronine uptake increased (P less than 0.001). In relation to the changes in the thyroid function parameters measured, we suggest that the primary target of androgen action was TBG biosynthesis. In five of…