I am a twenty five year old woman and have had diabetes for sixteen years. I’ve always been referred to as a “brittle diabetic.” My blood sugars are usually high with the occasional low. My doctor has just put me on Glucophage. I do take two insulin shots a day (Regular and NPH). I am a little scared about taking this drug due to the fact that I cannot locate any info on people with Type 1 diabetes taking it.

Glucophage [metformin, a pill for Type 2 diabetes] is not considered a first line drug for Type 1 diabetes, but theoretically it might still be useful in addition to insulin in some Type 1 diabetics, especially if they are overweight. This has not been formally evaluated yet.

Insulin deficiency (which must be treated with insulin injections) is the main problem in type 1 diabetes, but not the only problem. Because insulin is injected subcutaneously, it doesn’t go to the liver first the way it does when made normally by the pancreas. Normally this insulin that goes to the liver, prevents the liver from releasing excess glucose into the blood. In addition, the pancreas normally makes another hormone, amylin, which is deficient in people with type 1 diabetes. Amylin also interferes with release of glucose from the liver into the blood, and slows the absorption of food in the stomach so that the insulin doesn’t have to work too quickly.

People who are overweight, whether or not they have diabetes, have insulin resistance — that is, their insulin doesn’t work as strongly as it should and they have to make extra insulin to keep their blood sugar normal. If they can’t make enough extra insulin, their blood sugar will go high and they will develop type 2 diabetes. If the pancreas fails in someone who is overweight, they will develop type 1 (insulin deficient diabetes). If they are also overweight, they will have insulin resistance increasing their needs for insulin.

Glucophage helps restore normal insulin sensitivity to people who are insulin resistant. Glucophage can’t replace insulin, but can help make the insulin work better, and possibly decrease insulin requirements. It can also help counteract excessive release of insulin from the liver which is seen with type 1 diabetes. I am not aware of any formal studies evaluating the combination Glucophage and insulin in type 1 diabetes, but theoretically it might work, especially if the person is overweight.

Please discuss with your physician, however, what to do if you develop ketones, when you are sick or if you plan to get pregnant. Taking Glucophage when you are spilling ketones can cause lactic acidosis which could make you sicker. Make sure to test your urine for ketones if you get sick with any virus, are nauseous, or if your blood sugar is over 250 and call your doctor if they are positive. You will probably have to temporarily stop the Glucophage and may have to adjust the insulin if you are spilling ketones. Glucophage is contraindicated in pregnancy so you will probably want to be off if for 3-6 months before any planned pregnancy to re-regulate your blood sugar on insulin alone.

TGL
Additional comments from Dr. Bill Quick:

As Dr. Lebinger indicates, the use of metformin is “off-label” for people with Type 1 diabetes: that is, the FDA has not approved its use in Type 1 diabetes, as the manufacturer has not submitted information on either the efficacy or safety of its use in this circumstance. Remember, with off-label use, you are a “guinea-pig” but unlike scientific studies, there is no requirement that you sign an informed consent that you know the risks as well as the benefits. You should be aware that lactic acidosis is a potentially fatal disorder, and that metformin should never be used in any patient with any elevation of kidney tests, because of increased risk of this complication.

WWQ