Polycystic ovaries and insulin resistance
Posted on June 22, 2011
I would like to address the very important issue concerning insulin
resistance and PCO. I need to start by saying that, as with many things
in medicine, we though we had this figured out but in the end, we may be
a little off the mark. What is the definition of PCO? 2/3 of the
1) no or infrequent ovulation
2) physical signs of excess androgens, or high levels of androgens in the blood.
3) polycystic ovaries on ultrasound (12 or more little follicles on each ovary)
The physical signs of PCO vary considerably. Some women are thin and just don't ovulate, and have polycystic ovaries on ultrasound. The opposite is women who are heavy, abnormally hairy, have high levels of androgens; testosterone and the other male hormones. Even normal women have these hormones, but not in excess.
So your PCO may be completely different that your friend's PCO. And the treatment of your PCO may also be different.
Now let's get to PCO and insulin resistance.
Insulin is the hormone made by the pancreas that allows us to use sugar. Sugar (glucose) needs to get from our food, into the circulation and then into our cells. Cells can not function without glucose. It's the insulin that allows us to properly use the glucose. No insulin, no proper glucose utilization, no life.
Diabetes is a condition where there is a problem with insulin. Without insulin, blood levels of glucose rise to dangerous levels. Type 1 diabetics don't have insulin, and need to take insulin by injection.
Type II diabetics make some insulin. Some Type II diabetics make a small amount and need a little help with medications to improve the action of insulin. However, most Type II diabetics make more that enough insulin, but for some reason the insulin doesn't work well and glucose levels rise. So they have high levels of insulin and glucose. These patients are "insulin resistant". They also take medications to improve the actions of insulin.
Some women with Type II diabetes have PCO, some women with PCO have Type II diabetes. A number of decades ago, researchers noticed this relationship and started asking if PCO was related to diabetes and some progress was made in the area of insulin resistance. That is to say, it was determined that some women with PCO also have insulin resistance.
When all this came about, researchers were quick to say that all women with PCO have some degree of insulin resistance. They may not be diabetic, but their insulin levels are high. By the way, insulin resistance is not in the definition of PCO.
Here comes the most important point of this blog. Because insulin also acts a growth hormone, it can make people bigger and fatter. People who are insulin resistant, have higher levels of insulin and may be bigger. (Now I know that some of you are type II diabetics and have normal weight, but most type IIs are at least a bit overweight.) The idea was if we lower the insulin (with medications that help insulin work more efficiently) patients will lose weight, and ovulation will occur normally. And it's not just about the weight, there may be other benefits of lowering the insulin levels that help women with PCO. Lowering insulin levels also may lower the androgen levels.
Fred Licciardi, M.D. is a reproductive endocrinologist practicing in New York City