Have you ever had high morning blood glucose levels? Occasionally, you may wake up in the morning and check your blood sugar before breakfast, and your blood glucose levels are high. Higher than usual. What's going on? It could be one of several causes.First, it's important to know that the most likely cause of high morning glucose is inadequate nighttime insulin doses. In particular, increased counter-regulatory hormones in the early morning can make morning glucoses tougher to treat and may require higher nighttime doses or doses taken closer to bedtime.
Less often the problem may be due to something called the Somogyi effect, which is caused by rebound hyperglycemia after an episode of hypoglycemia while you are sleeping. This can happen to people who take long-acting insulins, and it can also happen if you didn't eat a snack before bed. The blood sugar drops and your body releases hormones to counteract the drop. The result? You wake up with a higher blood glucose level than you would like to see.
The Dawn Phenomenon
Or, it could be from the "dawn phenomenon," which happens during the night when hormones are released that trigger the liver to put out glucose. If there is not enough insulin in the body to counteract this, then blood glucose levels rise during the night, resulting in a high reading in the morning.
How to Tell the Difference
- The only way to know for sure? Wake up sometime between 2 and 3 a.m. for several nights in a row, and check your blood sugar. If you are low at that time, it could be the Somogyi effect. If you are normal or high, then the dawn phenomenon may be the culprit.
How to Counteract These Events
- Make sure to have a snack before bed that consists of more protein than carbs.
- Let your doctor know what is happening. He or she may change your medication or insulin dosages, or the timing of when you should receive insulin.
Additional Ways to Combat Dawn Phenomenon
- Exercising in the evening may help keep morning blood sugars in a better range.
- Eat breakfast, even if your blood sugar is high. Eating something will actually shut down the dawn phenomenon process and let your blood sugar return to normal.
"The Dawn Phenomenon." DOC News. 01 Jul 2006. Volume 3 Number 7 p. 5 American Diabetes Association. 24 Nov 2007.