There are so many facets to diabetes, from glucose to A1C to lipids to hormones. What do hormones have to do with diabetes? As it turns out, quite a bit. Is it crucial that you understand all the different pieces of the diabetes puzzle? Maybe not, but since I know the most of you are keenly attuned to your diabetes, you might find this week’s posting of interest (at least, I hope you do!).
What the Heck Are Hormones, Anyway?
According to the National Institutes of Health (NIH), hormones are “your body’s chemical messengers.” Hormones travel in your blood and target specific organs or tissues, and they’re involved in a whole bunch of things, ranging from growth and development to reproduction to metabolism and even to mood. The word “hormone” comes from a Greek word that means “to spur on.” Hormones are given as medicine (think insulin injections, thyroid hormone, estrogen replacement) when the body’s own production goes awry.
The endocrine glands make hormones, which are actually types of protein. Endocrine glands include the pancreas, the adrenal glands, the thyroid, the thymus, ovaries, testes, and the pituitary and pineal glands. Even the gastrointestinal system is an endocrine gland, in some ways. The brain sends the signal to the endocrine glands to release hormones, which then seek out target cells. Target cells have receptors on them, which allow the hormone to work its magic, such as activating a gene or producing energy, for example. I like to think of hormones as “movers and shakers” because they make things happen in the body.
The body produces many different kinds of hormones, and you certainly don’t need to know about all of them. Some hormones you’re probably already familiar with, such as estrogen, testosterone, growth hormone, and adrenalin, just to name a few. Some hormones are specifically or indirectly related to diabetes, so here’s a partial run-down:
Insulin. But of course! Insulin is made in the beta cells of the pancreas. It’s released in response to an increase in blood glucose (typically after a meal is eaten). Most of the cells in the body have insulin receptors to which insulin binds. Once insulin hitches on, the cells allow glucose to enter to then be used for energy. The problem comes in with diabetes, when the pancreas either stops making insulin (or makes very little), as in the case of Type 1 diabetes, or when insulin cannot be used properly or the beta cells tucker out, as in the case of Type 2 diabetes.
Glucagon. Insulin’s counterpart is glucagon, a hormone made in the alpha cells of the pancreas. Glucagon works in the opposite manner of insulin, as it acts to raise blood glucose and help keep blood glucose levels steady between meals. When glucose levels drop too low, glucagon is released and it targets the liver, which is prompted to release some of its glucose stores to help bring blood glucose levels back up into a safe range.
Glucagon is available as an injection (by prescription), and is given when a person with diabetes is hypoglycemic and is unable to take glucose by mouth or is unconscious. The glucagon injection typically raises blood glucose within about 15 minutes. Glucagon injections are rarely needed for people with Type 2 diabetes, however.
Amylin. Lest you thought that insulin and glucagon were the only pancreatic hormones to contend with, along comes another one: amylin. Amylin was discovered in 1987 and it too has a role in diabetes management. Secreted by the beta cells along with insulin, amylin also works to lower blood glucose levels after a meal. Specifically, it promotes satiety (makes you feel full so you stop eating), suppresses the release of glucagon, and slows the rate at which food leaves the stomach.
Amylin is available as the prescription drug Symlin (pramlintide), and is available for people with Type 1 or Type 2 diabetes who inject insulin and who have difficulty managing blood glucose with insulin or insulin and diabetes pills. Symlin must be given by injection, generally before each meal. It cannot be mixed with insulin.
I’ll let you digest these hormones for this week, and next week, we’ll look at even more hormones that play a role in diabetes.