Veterans With Diabetes International

Waking up with High Blood Glucose Levels
From Nina Nazor, Your Guide to Diabetes.

The Dawn Phenomenon and the Somogyi Effect Morning readings can be so frustrating! Do you go to bed with a blood
glucose of 120 mg/dL (6.6 mmol/L), and wake up with a blood glucose of 170 (9.4 mmol/L) or more? Is this happening in spite of following your diet, exercise and taking your medications as your doctor prescribed?

Well, don't worry; all this may be happening due to the Dawn Phenomenon or the Somogyi Effect (also called rebound hyperglycemia). Let's see what this is all about.

What is the Dawn Phenomenon?
Every human being experiences the Dawn Phenomenon. While we sleep, usually around 3-8 AM, glucose coming from glycogen -the molecule that stores glucose in our liver and muscles- is released in response of the stimulus of some hormones in order to repair and maintain our body.

These hormones are growth hormone, cortisol, glucagon, and epinephrine (also called adrenalin).

This group of hormones is known as counterregulatory hormones, since they have the opposite effect of insulin: they cause glucose levels to rise.

So, the release of these hormones causes an increase in blood glucose levels during the first hours of the morning and that is why it is called the Dawn Phenomenon.

What is the Somogyi effect?
The Somogyi effect happens when your blood glucose levels are high in the morning due to hypoglycemia (low blood glucose levels) overnight.

Having a low during the night, causes the body to react by releasing the same counterregulatory hormones that we already mentioned: growth hormone, cortisol, glucagon, and epinephrine.

Glucagon is the key hormone when we have hypoglycemia, because it makes our liver to start releasing glucose when there is an emergency. Sometimes when this happens, you can wake up with high blood glucose levels.

What can I do to prevent or correct this high blood glucose in the morning?

Limit your carbs at night and eat a small snack of fat and protein before bed, like a tablespoon of peanut butter, or some cheese and/or meat. No carbs, just protein and fat in that snack.

Try to exercise in the evening for at least 45 minutes at moderate pace, like walking or bicycling, since this type of exercise has a longer hypoglycemic effect that will help your blood glucose levels keep down during the night.

Talk with your doctor about an adjustment of your medications in the evening. If you take pills you might need another dose or an increase of the dose before bed. If you use insulin, you might need a little bit more of long acting before bed and/or some more for breakfast. If you use a pump, then it is easier and you just need to adjust your basal rate to prevent the blood sugar from rising during the night.

You should also eat breakfast. The increase in blood glucose after you eat your breakfast will often turn off the release of glucose from liver or muscles, since your body senses the fuel is coming through food. If you don't eat your breakfast because you are afraid your blood glucose is high, your blood sugar might continue to rise until noon or until you eat again.

Do not skip taking your medication in the morning. You must always eat breakfast and take your medication, so your body does not feel that it is in a state of emergency.

In the case of the Somogy effect or if you have lows overnight, you can try to go to bed with a blood glucose level a little bit higher than usual, which might prevent you from having a hypoglycemic event overnight.

Also, you might need to add some carbs and fat to your dinner or bedtime snack, in order to have a slower digestion and available carbs during the night.

In both cases, the first thing you need to do is to wake up between 3 or 4 AM and check your blood glucose levels, unless you already use a continuous glucose sensor like Glucowatch. If you are high, it might be the Down Phenomenon; if you are low, then it could be the Somogyi effect.

Anyway, record your readings and talk with your health care team so they make adjustments in your treatment to help you keep a better glucose control.