Two common reasons for this are the Dawn Phenomenon and the Somogyi Effect:
Dawn Phenomenon
Every human being experiences the Dawn Phenomenon. While we sleep, usually around 3-8 AM, glucose is released in response to 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), which are also known as counterregulatory hormones, since they have the opposite effect of insulin: they cause glucose levels to rise.
- About.com - The Dawn Phenomenon and the Somogyi Effect
Somogyi Effect
The Somogyi Effect happens when your blood glucose levels are high in the morning due to hypoglycemia (low blood glucose levels) overnight. [Low blood sugars can occur when there is extra insulin in the body.] This is also called rebound hyperglycemia, since your body reacts to low blood glucose levels by increasing the release of glucose from muscles, liver and fat, therefore causing hyperglycemia.
- About.com - The Dawn Phenomenon and the Somogyi Effect
How Can You Tell the Difference?
- If the blood sugar level is low at 2 a.m. to 3 a.m., suspect the Somogyi effect.
- If the blood sugar level is normal or high at 2 a.m. to 3 a.m., it's likely the dawn phenomenon.
- A-Z Health Guide from WebMD: Dawn phenomenon and the Somogyi effect
What Can You Do?
Once you and your doctor determine the cause, there are a number of options. These include changing the time, the type, or the amount of insulin you take, making adjustments to your evening snack, or switching to an insulin pump.
Resources:
About.com - The Dawn Phenomenon and the Somogyi Effect
A-Z Health Guide from WebMD: Dawn phenomenon and the Somogyi effect
WebMD - Diabetes: Morning High Blood Sugar Levels
