Newsletters About Diabetes 

DIABETES CARE: THE DAWN PHENOMENOM

3/20/2008
You wake up at 8 a.m., check your blood glucose, and find it’s higher than when you went to bed.

DIABETES CARE: THE DAWN PHENOMENOM

You wake up at 8 a.m., check your blood glucose, and find it’s higher than when you went to bed. You haven’t eaten anything all night or had breakfast yet, so what’s the culprit?

 It could be the dawn phenomenon. By definition, this is an early-morning rise in blood glucose without a preceding low. While there are other possible causes for those morning highs, such as stress or too little insulin at bedtime, dawn phenomenon is fairly common among diabetics and something everyone with diabetes-particularly people with Type 1 diabetes-should understand.

The science behind dawn phenomenon goes something like this. Between 3 a.m. and 8 a.m. (while you are snoozing soundly), your body naturally releases hormones. These hormones trigger a rise in blood glucose to give you energy and that get-up-and-go to start your day. It is natural, normal, and it happens in everyone-with or without diabetes.

The dawn phenomenon is nature’s way of telling the body to get ready for a new day, says M. James Lenhard, MD, FACE, section head of endocrinology and metabolism at Christiana Care Health System in Wilmington, DE.

For people with diabetes, the dawn phenomenon can be problematic. People with diabetes either don’t make or can’t use their own insulin to effectively counteract this surge in glucose. Blood glucose goes up in the early morning and stays up.

The dawn phenomenon makes it difficult to get blood glucose levels under control during the rest of the day, says Donna Tomkey, MSN, RN, CDE, CNP, nurse practitioner and diabetes educator at Lovelace Sandia Health Systems in Albuquerque, NM. “If you start the day sweet, the whole day goes sweet,” says Lenhard. He adds that starting the day behind the eight ball with a blood glucose reading of 200 mg/dl before breakfast means that you’ll take more and more insulin throughout the day. Also, dawn phenomenon can hamper your goals for good glucose control, which can increase your chances of developing complications from diabetes.

The severity and frequency of dawn phenomenon varies from person to person, and can change over time. Oh, great, so how will you know? For one, people with type 1 diabetes are more likely to experience dawn phenomenon, and the odds of it happening increase the longer you have diabetes.

Dawn phenomenon can also strike people with type 2 diabetes, and the more insulin resistant you are, the more likely you are to experience it. If you notice unexpectedly high readings in the morning, talked to your doctor or diabetes educator. He or she may have you check your blood sugar readings at, say, 6 a.m. and continue checking every hour until 10 a.m. If your blood sugar readings increase during that time, without eating breakfast, you may be experiencing dawn phenomenon.

Some diabetics will have a much more severe dawn phenomenon than others, says David Schade, MD, professor of medicine at the university of New Mexico Health Sciences Center in Albuquerque. You can treat dawn phenomenon with insulin injections or you can program your insulin pump to release extra insulin during the early morning. In fact, this can be a compelling reason for switching to an insulin pump, says Tomky, so talk it over with your doctor or diabetes educator.

Also, dawn phenomenon can hamper your goals for good glucose control, which can increase your chances of developing complications from diabetes.