Stress and Type 1 Diabetes

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Acute pyschological stress affects glucose concentrations in patients with type 1 diabetes following food intake but not in the fasting state, by P. Wiesli and colleagues. Diabetes Care 28:1910–1915, 2005.

What is the problem and what is known about it so far?

People with diabetes often have trouble keeping their blood glucose at a steady level. Studies have shown that stress can cause glucose levels to rise or fall. However, it's not clear how eating affects glucose levels when people with diabetes are under stress. In one study, people with diabetes performed a stressful task after eating, and this study showed that stress did not affect glucose levels very much. Another study tested people with diabetes who had not eaten. In this study, performing a stressful task resulted in a rise in glucose levels. Those people could have had lower glucose levels because they had not yet eaten.

Why did the researchers do this particular study?

The researchers wanted to find out how performing stressful tasks before and after eating affects glucose levels in people with type 1 diabetes.

Who was studied?

Patients with type 1 diabetes who went for regular visits to the University Hospital of Zurich were invited to take part in the study. Subjects were not allowed to take part if they had diabetes for less than 3 years, had high blood pressure or other ailments, or were taking various medications.

How was the study done?

Forty people with type 1 diabetes were chosen to take part in two separate studies. Twenty patients took part in study 1, and twenty patients took part in study 2. The people in study 1 were asked to perform stressful tasks without having eaten, and the people in study 2 were asked to perform stressful tasks after eating. At the beginning of the studies, the people were asked questions about whether they had symptoms of depression or anxiety, whether they had chronic stress, and how they reacted to emotional stress.

The stressful tasks consisted of a 5-minute preparation task; a 5-minute speech task, where the participants had to introduce themselves and apply for a job; and a math-related task, in which they had to try to solve a math problem in front of an audience and at least two people who were wearing white lab coats. During the test, the patients' glucose levels were checked every 5 minutes, and blood pressure and saliva samples (to test stress hormones) were taken.

What did the researchers find?

As compared with a "control day," when the patients didn't perform any stressful tasks, the glucose levels of the patients who didn't eat stayed the same during the test day. Their blood pressure and heart rate, however, rose during the tests. Glucose levels also stayed the same between the control day and the test day in the patients who ate a meal. However, after eating, it took longer than normal for glucose levels to go down after taking the tests. Blood pressure and heart rate also rose during the tests. The researchers did not find anything important in the saliva samples for either group of patients because the samples were either too small or were damaged while in storage.

What were the limitations of the study?

There are three main limitations to this study. First, the researchers only tested "interstitial" glucose, or the glucose in the fluid surrounding the body's tissues, and not blood glucose. Second, the researchers measured only one stress hormone, and the saliva samples they took from the study subjects were either too small or damaged. Third, the patients were under stress for only a short time, so the effect of longer-lasting stress on glucose levels was not found.

What are the implications of the study?

The findings of this study show that it is important for patients with type 1 diabetes to know if they will be under mental stress and if that stress will happen before or after eating. Although there was no real change in glucose levels for the patients who had not eaten, the glucose levels of the patients who had eaten took longer to come down after they experienced stress.

For more information

Stress

Stress management improves long-term glycemic control in type 2 diabetes, by R.S. Surwit and colleagues. Diabetes Care 25:30–34, 2002.

Diabetes A to Z: What You Need to Know About Diabetes—Simply Put. 4th ed. (Alexandria, VA, American Diabetes Association, 2000)