Diabetes is a disease in which a person has high blood sugar, either because the pancreas does not produce enough insulin, or because cells do not respond to the insulin that is produced.
People with type 2 diabetes are sometimes told to wait after using insulin for the drug to work its way into the body before they can begin eating, but a new study from Germany says that's not necessary.
In a group of about 100 diabetics, researchers found that blood sugar levels remained steady regardless of whether or not participants left a 20 to 30-minute gap between using insulin and eating a meal. The diabetics overwhelmingly preferred being able to eat right away, too.
"It's a very promising result. It will lead to better adherence and satisfaction," said Dr. Aaron Cypess, a staff endocrinologist in the clinic of the Joslin Diabetes Center in Boston who was not involved in the study.
Insulin gives glucose - or blood sugar - access to the body's cells to be used as fuel. But in type 2 diabetes cells are resistant to insulin or the body doesn't make enough of the hormone, so glucose remains in the bloodstream and can climb to dangerously high levels.
Injectable insulin is available for diabetics in a newer fast-acting form, but it's expensive and many still use human insulin, which takes some time to become active in the body. So doctors often recommend waiting to eat after using human insulin to prevent blood sugar spikes.
Not all experts think waiting is necessary, though, according to the researchers led by Nicolle Mueller of Universitätsklinikum Jena. To see what difference it makes, Mueller and her colleagues randomized type 2 diabetics into two groups.
For four weeks, one group of 49 people waited 20 minutes to eat after using human insulin. Then they switched to eating immediately after injecting insulin for another four weeks. A second group of 48 diabetics did the same in reverse order, eating immediately after injection for the first four weeks, then observing a waiting period for the next four.
Using a blood test that measures average glucose levels over time, the researchers found that all the participants had generally higher than ideal blood sugar levels - but the difference in those levels between periods when they waited or didn't wait to eat after insulin injections was a negligible 0.08 percent.
The participants also reported about the same number of high-blood sugar episodes between the two time periods, and about 87 percent of them said they "significantly preferred" doing away with the 20-minute wait altogether.
Cypess said people should talk with their doctors before making any sort of change to their insulin routine.
"What would I do with a patient who is moderately adherent to what I recommend? I'd say give it a shot," he said, because it's better for people to eat closer to the time they use insulin.
"This is really useful, because you get into a problem if people are supposed to take insulin so many minutes before. That's where adherence goes down," he said.
These results may also allow some people to switch from the fast-acting insulin analogs to the less-expensive human insulin, said Cypess, but he added that more studies would be needed to compare the two.
He also warned that people shouldn't assume these results apply to people with type 1 diabetes, whose bodies produce virtually no insulin.
"Talk to your doctor," he said.
