In M-->F, oestrogen treatment prevented bone loss after testosterone deprivation. In F-->M the testosterone dosage used, associated with a decline in serum oestradiol levels, was unable to maintain bone mass fully in all subjects in the longer term. The inverse relationship between BMD and serum LH levels suggests that the dose of hormone replacement has been too low in subjects with a decline in their BMD. Its cause might be underdosing or non-compliance in some patients. We propose that serum LH levels may be used as a measure of the adequacy of replacement with sex steroids.

The effects of treatment with estrogens and antiandrogens in male to female (M-->F) transsexuals and androgens in female to male (F-->M) transsexuals on their respective bone metabolism, bone mineral density (BMD), serum insulin-like growth factor I (IGF-I) and IGF-binding protein-3 (IGFBP-3) levels were investigated. BMD and variables of bone turnover in serum were measured at baseline and after 3 months (except for BMD) and 1 yr of treatment in 56 M-->F and 35 F-->M transsexuals. Serum IGF-I, IGFBP-3, and propeptide of type I procollagen (P1CP) were measured at baseline and after 1 yr of treatment in 10 M-->F and 10 F-->M transsexuals. In M-->F, BMD increased significantly. Bone turnover decreased, as shown by a significant decline in levels of osteocalcin, alkaline phosphatase, P1CP, and fasting urinary calcium/creatinine and hydroxyproline/creatinine ratios. Serum IGF-I levels decreased significantly without significant changes in IGFBP-3 levels. In F-->M, BMD did not change. Bone formation increased, as suggested by an increase in alkaline phosphatase and a borderline increase in P1CP values. IGF-I levels increased significantly, whereas no significant changes were seen in IGFBP-3 levels. We conclude that in males, estrogens (in combination with antiandrogens) decrease bone turnover, with a subsequent increase in BMD and a decrease in serum IGF-I. In females, testosterone administration increases bone formation, but this is not reflected in an increased BMD, whereas serum IGF-I increases.

No abstract

No abstract

Prostates were small after long-term estrogens only. The sex steroid receptor content was considerably changed. PSA and PAP in the specimens suggested that their production does not depend on testicular androgens alone.