1. Health
You can opt-out at any time. Please refer to our privacy policy for contact information.

Dawn Phenomenon or Somogyi Effect? What's the Difference?

By November 19, 2007

Follow me on:

You wake up in the morning and check your blood sugar before breakfast. And it's high. Higher than it usually is in the morning. What's going on? It could be one of two causes. Dawn phenomenon and the Somogyi effect both can raise your fasting blood glucose levels in the morning, but for different reasons.

Both occurrences are very similar in some respects and have to do with hormones that tell the liver to release glucose into your blood stream while you sleep. The difference is why the hormones are released.

The Somogyi effect is caused by having too much insulin in the blood during the night. 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 while you are sleeping 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 happens because during the night, 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 which one might be making your morning glucose levels high, is to 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.

What to do 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.

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.

Photo courtesy of Stockbyte/Getty Images

November 19, 2007 at 1:05 pm
(1) j.francis says:

i think that in order to decide ‘denial’ the facts should be looked at. like consecutive readings of 5.8,5.9,5.9 A1c. Mornig reading excellent(under 105)I suspect that i am being considered as ‘in denial’ but i look at the statisics. am i wrong???

November 22, 2007 at 3:46 am
(2) nkwoong says:

That still does not explain the exceptional high bg I had in two occasions in the low 200′s of post prandial one hour. First of all, oat meal is a good complex carbohydrate (ADA does not admit wrong about their position on complex carbohydrates, and they are going to make some kind of announcement based on the latest research,but how many T2s have been misled) that can have a lowering effect on cholesterol and possibly bg. Second, I only ate a small banana, a different species of the regular banana. And, finally I had a small portion of low glycemic cereal with flaxseed.

Maybe a combination of factors, including stress the previous day. I never had that kind of reading since on Met, day or night. I metered up to three times a day some day and I am on a low carb diet everyday and very careful what I eat. I eat banana and take supplements of magnesium, calcium and potassium for my leg cramps. They went away once I drink this fortified organic soy milk that contains ALA, potassium and vitamins.

Leave a Comment

Line and paragraph breaks are automatic. Some HTML allowed: <a href="" title="">, <b>, <i>, <strike>

©2014 About.com. All rights reserved.

We comply with the HONcode standard
for trustworthy health
information: verify here.