It is known that sex steroid hormones play an important role in the maintenance of bone mass in males as well as in females.
Even though androgens are the major sex steroids in men, their primacy in regulating male skeletal remodeling has been increasingly questioned as direct and indirect evidence emerged suggesting that estrogens may also play a major role in male skeletal health.
Recent data suggested that a threshold level of bioavailable estradiol is needed to prevent bone loss, and that with aging an increasing percentage of elderly men begin to fall below this level.
The testes account for, at most, 15% of circulating estrogens in the male; the remaining 85% comes from peripheral aromatization of androgen precursors in different tissues, including bone.
