Ask The Expert
Insulin

There is a common concern that some oral agents or insulin can cause weight gain.

What insulin does to the body:

1. Regulates the liver from releasing too much glucose (I like to say that insulin leans up against the door of the liver and only lets a little glucose out at a time).
2. Acts as a "doorman, or key" to open the doors of the cells and allow glucose to enter the cells.
3. Acts as a storage promoter, to store extra glucose back into the liver, along with the muscles, while the excess is stored as fat.

The person without diabetes:

So as a person without diabetes, whenever I overeat, my pancreas automatically releases extra insulin to take care of my extra food intake; if I don't exercise it off, that excess food gets stored as fat and I gain weight. Remember Rhoda on the Mary Tyler Moore Show? To paraphrase her comment, she said "don't bother giving me that candy bar-just apply it directly to my hips, since that's where it will eventually end up!"

The person with diabetes:

In contrast, with diabetes, if you don't have enough insulin, then when you overeat, not all the food can enter the cells (to store in the liver and muscles, with the excess stored as fat); some of the glucose from your food just piles up in the blood, and gets urinated out-what I call a "false" weight loss/weight control.

What insulin does to the body:

If your diabetes were out of control for awhile, you were losing weight without trying; then as your blood glucose improved from taking diabetes medication, this would mean that instead of urinating out your food/calories, you were now able to retain your food and use it as energy (as well as store the excess in muscle and fat). The long-term studies proving that good diabetes control matters (i.e. the DCCT and UKPDS) also showed that people gained weight as their control improved. Despite the fact that losing weight and exercising are the keys to decreasing the risk of developing type 2 diabetes or to controlling diabetes and decreasing the risk of heart disease, experts have also agreed that: 1) controlling glucose is important, even if it means gaining some undesirable weight (the average weight gain in the DCCT was 10 pounds); 2) certain diabetes medications may not cause as much weight gain as others; 3) careful meal planning and exercise can help to limit the weight gain.

Overeating:

True, if you are overeating and/or not exercising enough, and are thus requiring more oral agents or insulin, then you will gain weight because the diabetes medication is supporting your excess food intake. In the April, 2002 issue of Diabetes Forecast, Sheldon Gottlieb, MD addressed the issue of diabetes medication and weight gain, and commented that some people use insulin as a "carbohydrate credit card." I hope you get my point that in this instance, the diabetes medication itself did not cause weight gain, but rather the excess calories did.

Insulin sensitizers (Thiazolidinediones) and weight gain:

These drugs (trade names Actos® and Avandia®), which are used in treating insulin resistance, also are associated with weight gain. They interact with a receptor in tissue that may convert it into fat cells, although how this occurs is not yet well understood. Despite the weight gain, this class of drugs is associated with improved cardiovascular function. To limit the weight gain, the drug Metformin (trade name Glucophage®) is often added.

Insulin and weight gain:

Generally, we tend to say that people might be prone to gain more weight on insulin, rather than on oral agents. But in addition to the issues discussed above, another common reason for weight gain is often related to the actual insulin regimen one is on - i.e. if you take pre-mixed, intermediate, or long-acting insulin twice daily, you are forced to eat on time, to avoid skipping meals, and to anticipate exercise by taking an extra snack or decreasing your insulin, etc.-and this restricted regimen makes it harder to control weight. Often, using a rapid-acting insulin with each meal, with a bedtime dose of Lantus or NPH, or using an insulin pump, combined with careful diet and exercise, will allow you more flexibility in your lifestyle and an easier time controlling weight.

You can see that there are many factors to consider. I would encourage you to discuss this information with your diabetes educator and physician, so they can determine what is the best treatment for you.