March 9, 2002
Type 2
Question from Los Angeles, California, USA:
I am 5 feet, 10 inches tall and muscular for a woman, but nine years ago, at time of my diagnosis of type 2 diabetes, I was quite overweight (248 pounds). I went on a low fat diet and once I got my weight down to 218, my blood sugar normalized. I continued to lose weight until I was down to 199. Now I weigh 212 pounds, but my blood sugar is not good at all. Two weeks ago, I was waking up with readings of around 200 mg/dl [11.1 mmol/L] so my physician put me on Glucovance yesterday, and I have several questions:
Why is it that even though I am below the weight at which my sugar normalized some years back, I cannot now achieve control through weight/diet control? Does one’s “set point” change over time so that weight maintenance alone does not work anymore at the same weight?
Is it possible my pancreas is pooping out and not making as much insulin?
Based on the fact that weight loss seemed to work in the past, I suspect I still have insulin and am just not sensitive to it. Is there a way to see if I do in fact have plenty of “home grown” insulin?
I note that Glucovance, in addition to making one better able to use whatever insulin you have, also apparently pushes your pancreas to squeeze out more insulin. I am leery of “wearing out” my pancreas, and equally leery about the effects of too much insulin on the body and thus wonder if I should not be on a drug that merely maximizes my use of natural insulin. Are these concerns medically valid? Have long-term studies been done to see if people on a drug which forcibly increases insulin production experience an earlier end to natural insulin production?
Typically, how long will a person have to be on Glucovance to see by if it is having any effect?
Answer:
The answer to your first question is yes; the set point can change over time. Type 2 diabetes has a progressive course. What worked two years ago may not be sufficient now.
Progression, to some degree, does involve a progressive loss of beta cell function. There are several ways of performing provocative stress tests which measure insulin secretory reserve. A simple place to start is to get a two-hour postprandial glucose and C-peptide levels to see how much insulin you make in response to a meal. There are other tests which can be performed which become more complex to perform. You should talk about these and your need for them with your physician.
You bring up good questions regarding the component of Glucovance which stimulates your own insulin secretion. This component is the sulfonylurea. These oral agents have been used for many years. The good news is that Glucovance allows for a smaller dose of the sulfonylurea than if it is used as a single agent. Although it remains a theoretical possibility that beta cell exhaustion may occur earlier with sulfonylureas, this has never been shown. I think you have to look at what good it will do in the short-term to maximize blood sugar control.
Generally, only two to three weeks are required to evaluate the drug’s efficacy. I would add that a less than optimum response could be countered with a change in the dosage of the drug, as well.
JTL
