Why is my Blood Sugar so High in the Morning?
There are two main reasons that blood sugar levels may be higher in the morning. These are referred to as the “dawn phenomenon” and the “Somogyi effect”. The dawn phenomenon is the result of various changes that occur naturally in the body during sleep. It refers to increased glucose production and insulin resistance (approximately 3am-8am), which are brought on by the release of counterregulatory hormones (including cortisol, epinephrine, and glucagons). So, the release of these hormones to maintain and repair your body actually causes blood glucose to rise during the first hours of the morning. The Somogyi effect, or “rebound hyperglycemia”, can occur as a result of low blood sugar levels overnight. The hypoglycemia triggers the release of counterregulatory hormones, which increase blood glucose. It is thought that the Somogyi effect may be a result of poor diabetes management. For example, those taking insulin may have injected too much earlier, creating hypoglycemia with a “rebound” hyperglycemia to follow.
I would recommend contacting your doctor to determine which of the above phenomenon may be causing your hyperglycemia in the morning. You will likely be asked to check your blood sugar levels every few hours from bedtime until morning. If blood sugar is normal or high during this time, the dawn phenomenon is likely occurring. If blood sugar is consistently low, the Somogyi effect is suspected.
If your blood sugar is consistently high during the night (dawn phenomenon), I would monitor/reduce intake of carbohydrates after dinner and consider choosing a bedtime snack that is full of protein. For example, choose a hard boiled egg, lunchmeat, or peanut butter. With your physicians approval, you might also do some moderate exercise in the evening, which can help keep blood sugar levels down. If you are struggling with low blood sugar overnight (Somogyi), consider a complex carbohydrate + protein as a bedtime snack (whole wheat toast + peanut butter).Login to Favorite