Dr. Sarrel describes testosterone's role in a woman's body.
Well, it’s a little bit complicated when you ask, “How do you explain to a woman?” It’s tough explaining it to physicians because remember they never had a year to go and sit and study how testosterone works. In that year of studying testosterone, what I was able to find in medical research was about 200 different actions in a woman’s body of testosterone.
Well, I am not going to sit with somebody and say, “Well, here are the 200 different cellular actions,” but what I am going to say is testosterone, number one, of course works in muscle. So not only in athletes’ muscles, and you know they do abuse androgens in order to hyper-make their muscles, but in fact it’s very important in maintaining the structure, the cell growth, the function of the muscles in your body. So it’s not surprising that if there’s not enough of the androgens, weakness would be one of the things you would experience.
We also know that many of the different actions of testosterone affect sexual function. The one that’s been most closely identified and studied and over since the 1930s seen to be related to too little testosterone in the body is the problem of loss of sexual desire. And we will say more of that, but what this is getting at is testosterone acts in the brain, and there are specific sites in the brain, both in men and in women, where testosterone from the bloodstream enters brain cells and stimulates sexual desire.
So we do have actions in the brain. There will be other actions having to do with memory, having to do with mood. For example, too much testosterone can cause angry outbursts; too little testosterone has been related to depression. So we have many different actions in the brain of testosterone. And then there’s another major area that should be mentioned and that’s bone.
The reason why bone is important is we have come to realize that the production of testosterone in a woman peaks when she is in her middle 20s and declines on a steady slope in the decades that follow. As a result, by the time she gets to be 50, her blood level is about half of what it was when she was 25, and when she gets to be 60, it’s half of what it was when she was 50. So in fact, what we have seen that correlate with is loss of bone.
Bone density peaks when you are in your mid 20s, and unless you exercise adequately and have a good diet and do all the things you can to maintain your bone cells, the natural processes in the body are going to lead to bone loss. It’s particularly a problem.
You know, we have a real issue in this country of women who because of a disease wind up having a surgical menopause, lose their ovaries and lose their uterus, and that can happen when you are 28 or 32 or 35. And we know those women are at particular risk for bone loss.
Sometimes we know they can be given, in fact, most often they can be given different kinds of products that help protect the bone, but the actions of testosterone in bone are unique.
First, because testosterone promotes the growth of new bone, and second, because it slows the resorption of bone. The biggest problem for women who lose bone and develop the condition called osteoporosis is that the cells–see bone is constantly being turned over in the body. It has to. If you had the same bone at 25 and at 32, it would be so brittle it would just break.
So the bone cells are constantly turning over and laying down new bone, and there are other cells that are absorbing the old decrepit bone. Well, if you have too much activity of sucking up the bone cell—those are called osteoclasts that do that—then you lose too much bone, and testosterone slows that, but it also promotes the growth of new bones. The only hormone we know that does both.
So you see, whether it be actions in the brain, actions on sexual function, and I will say more about that in just a moment. We know there are important actions in the cardiovascular system that testosterone has.
About Dr. Sarrel, M.D.:
Philip M. Sarrel, M.D., completed his medical education at New York University School of Medicine, his internship at the Mount Sinai Hospital, and his residency at Yale New Haven Hospital. In addition to his many years on the faculty of the Departments of Obstetrics and Gynecology and Psychiatry at Yale University School of Medicine, Dr. Sarrel has also been a Faculty Scholar in the department of psychiatry at Oxford University, Visiting Senior Lecturer at King’s College Hospital Medical School at the University of London, Visiting Professor in Cardiac Medicine at the National Heart and Lung Institute in London, and Visiting Professor in the Department of Medicine at Columbia University College of Physicians and Surgeons in New York. He is currently Emeritus Professor of obstetrics, gynecology, and psychiatry at Yale University.