by Peter J. Nebergall, PhD
Today, almost 21 million Americans have diabetes. Perhaps 40 million more have
“pre-diabetes,” also called “impaired glucose tolerance”
or IGT. Ninety percent of diabetes is the type 2, insulin-resistant variety.
Type 1 diabetes occurs when the body does not produce enough insulin on its own. To treat type 1, you must restore the proper amount of insulin—either by taking insulin (through injection or inhalation), or by receiving a transplant, either of an entire pancreas or of specialized pancreas cells, called islet cells.
Type 2 diabetes occurs when the body produces enough insulin but gradually loses the ability to process its own insulin, called “insulin resistance.”
Type 2 is usually controlled first through diet and exercise, which improve your body’s ability to process its insulin. For most type 2 diabetics, however, diet and exercise changes are not enough. The next step is oral diabetes medication.
Oral Medication Review
The first successful “diabetes pills” were the sulfonylureas (glyburide, glipizide, glimepiride, tolazamide, chlorpropamide, and tolbutamide). These are insulin secretagogues, that is, chemicals that stimulate your pancreas to produce more insulin. When you take these medications, your body is still not processing insulin as effectively as it should, but there is more of it in your bloodstream to process. These drugs work for a while, often for years, before insulin injections may become necessary.
For decades, sulfonylureas and insulin injections were the only medicinal options for type 2 diabetes. More recently, another group of oral medications have been developed that, like the sulfonylureas, stimulate increased insulin production. These medicines, called the meglitinides (repaglinide/Prandin and nateglinide/Starlix), are more effective than the first generation of drugs, but they accomplish the same purpose—that is, they overcome insulin resistance by increasing insulin supply.
The
obvious problem with the insulin-increasing medications is that they become
useless when the pancreas ceases insulin production, as it eventually does in
many type 2 diabetics. At that point, insulin must be injected.
Newer diabetes medications attack type 2 at its source: “insulin resistance,” the body’s increasing inability to process insulin. Metformin (trade name Glucophage), and the glitazones (trade names Actos and Avandia) directly attack the problem, making the body (temporarily) more sensitive to insulin action. These medicines can be prescribed alone, with the sulfonylureas, or in a “compound” medication like Avandamet (Avandia and Metformin). Metformin and the glitazones help the type 2 diabetic make better use of the insulin he or she still produces. They are useless where insulin is not present; they are not a substitute for insulin.
A third category of medicines, the alpha-glucosidase inhibitors (acarbose/Precose and glyset/Miglitol) is completely different. These drugs temporarily suppress the digestive enzymes which turn carbohydrates into glucose, slowing digestion and glucose absorption, keeping glucose levels more even. More a dietary management tool than antidote to insulin shortage, these medicines help some diabetics keep a more stable blood glucose level, and avoid post-prandial spikes. Unfortunately, they can have many side effects, and are less than universal in their utility.
One important thing to remember is that no drug available today, including insulin, does anything more than treat the symptoms of diabetes. No drug, no herb, no food additive cures diabetes—though many unscrupulous touts would have us believe theirs will. Save your money.
Psychological Insulin Resistance
Unfortunately, oral medications are often eventually insufficient. Many type 2 diabetics, diagnosed as young adults, at first successfully control their condition with diet and exercise, but find they need the pills as they grow older. A number of years (and dosage increases) later, these diabetics have reached the limit of what oral medications can do for themand really need to start injecting insulin to keep their blood glucose at a safe level. (Note: Regular, frequent blood glucose monitoring and HbA1c testing will show if you have reached the point where you should begin insulin therapy.)
Here we encounter what the drug companies call “psychological insulin resistance.” Some of this is plain old fear of sticking yourself with needles—nurtured by memories from our childhood in the bad old days of dull-as-nails reusable syringes! Many men would rather face a bayonet. But some doctors contribute to the problem when they don’t make it clear to the patient why staying with oral medications is no longer working. Staying on the now-useless pills means that blood glucose will be out of control. Poorly controlled glucose leads to heart disease, stroke, blindness, kidney failure, neuropathy, and even amputation. Even worse, some doctors assume their patients would resist commencing regular insulin injections—so they don’t even suggest it. Yes, insulin is a powerful medication, with risks if used incorrectly—but what in this world DOESN’T have risks if used incorrectly? The risks of remaining on oral diabetes medications once pancreatic insulin has diminished or ceased entirely are far greater than the risks of taking insulin.
Oral Insulin?
Exubera is a milestone—an inhalable “oral insulin.” For the first time, we have an insulin that does not require injection. Insulin has become just another “oral diabetes medication.”
But there are problems. First, Exubera is “fast” insulin, with
a response curve quite similar to that of Humalog. There are no longer-acting,
inhalable insulins, yet. Will there be, eventually? Probably—just not
yet.
Another problem is high cost. Exubera does what fast injected insulins do, without
the needle-stick, but at about twice the price. Your insurance may or may not
accept that cost (and the British National Health Service has refused to provide
it, claiming the extra cost is too high). Look for the cost to drop, especially
as more oral insulins are FDA-approved.
Conclusion
It is now far easier for you and your doctor to tailor your oral diabetes medications to your specific needs—improving your control and lessening your possibility of serious complications.
Oral diabetes medications are a means to an end. The point is to keep your
blood glucose down in the normal range by whatever means necessary. Whatever
gets that job done is what you should be using. Diet and exercise, pills, or
insulin—they’re just tools. Use
the right tools, do your best, and win.