As Published in TGForum
and Transgender Community News

Osteoporosis is a naturally occurring disease state where the bones become more porous with age leading to increased long bone and skeletal fractures. This has been traditionally thought of as a disease which affected menopausal women but recent studies have shown that younger women and older men develop the same loss of bone structure in smaller numbers. But if left untreated will develop the same fracture rates, which may increase by as much as 50% over the person with normal bone density.  It has been known since the 1940's that hormones both estrogens and androgens play a significant role in bone formation from adolescence on. We have now come to realize that both men and women have both circulating androgens and estrogens, which produce the secondary sex characteristics that we are trying to change. In fact, in absolute amounts women have more circulating androgens than estrogens, when you realize that the precursors of the active estrogens are androgens.

Bone is not the inert structure seen in a skeleton, but a lively matrix of cells, both bone-building known as osteoblasts and bone-resorbing known as osteoclasts. The balance of these cells which are dying and being replaced on a daily basis is what determines bone strength. The total numbers of these cells determines the critical balance. While hormones play an important part, heredity, nutrition and weight bearing exercise are equally important. But since some of us are taking hormones or contemplating taking them, what should we know for the future? While I must say the amount of knowledge gained in the last ten years is staggering, the complete answer as to what we should do is still incomplete, but I will try to say where we are.

A few basic facts are well established. Bone growth is greatest through puberty and adolescence and bone mass reaches its maximum in the thirties. While bone density is stable for the next 10 years, in the late forties or early fifties bone loss starts and increases significantly after menopause and andropause. While the complete mechanism of estrogen effect on bone is not completely clear, it has been confirmed repeatedly that Estrogen HRT post menopause will increase Bone Mineral Density (BMD) and decrease fracture rates for up to 10 years, but then may lose its effectiveness. It also appears that the addition of androgens given to menopausal women and andropausal men increase BMD. In men it has been conclusively shown that androgen deprivation through castration or androgen blockade will decrease BMD and increase osteoporosis. The role of progestins as medroxyprogesterone acetate (MPA) is less well understood. Since we may be burning the candle from both ends, we must pay attention now or pay later.

In a small study of 28 MTF transsexuals, where BMD was measured after estrogen use for two to three years, it was shown that they were able to maintain their BMD comparable to normal men and were able to increase their BMD at sites in the hips, where the majority of debilitating fractures occur. Another one year study in MTF's showed a decrease in bone turnover rate and an increase in BMD.  Both studies had young participants and no one knows the long term effects on bone of these hormones in the TS population. Generally it appears beneficial from this one point of view.

Now since we are all young, we must accumulate the most bone mass we can before age related bone loss starts. Through exercise, which requires mechanical loading such as weight lifting and muscle crunching, we can improve our bone mass.  There are good studies which show improved BMD and new bone sites being formed on the long bones with exercise. Mechanical loading when combined with estrogen results in a greater bone response than either done separately.  The ingestion of dietary calcium and Vitamin D in only the minimum daily requirements has shown to decrease fracture rates in people with osteoporosis, without changing BMD significantly. Oral calcium supplements with Vitamin D may not be as effective since most of it is excreted without being absorbed. But would seem a likely alternative if dietary ingestion is poor. My suggestion would be that after the age of forty, if you are on hormones, a base line Bone Mineral Density test be performed and then checked every 5 years. If you are found to be osteoporotic, then there are new medications such as Fosamax and Raloxifene and a new group of Bisphosphonates, which can slow the rate of osteoporosis and remodel bones without interfering with your hormones.

Best of Luck in Your New Future,

Cerise Richards, M.D.