Which statement about the dawn phenomenon is true?

• A. Early morning hepatic glucose production driven by circadian hormones; managed by adjusting evening insulin or bedtime snack.
• B. Dawn phenomenon is caused by exercise at night
• C. Dawn phenomenon is when morning hyperglycemia is due to daytime meals
• D. Dawn phenomenon is related to nocturnal hypoglycemia episodes solved by exercise

Answer: (A)

The dawn phenomenon is the early-morning rise in blood glucose caused by the liver continuing to release glucose under the influence of circadian hormones such as growth hormone and cortisol, leading to hepatic glucose production overnight. Because this rise comes from the liver’s overnight output, it’s often best addressed by adjusting the evening insulin dosing or altering a bedtime snack to blunt that hepatic glucose release. It’s not driven by exercising at night, nor by daytime meals, and morning hyperglycemia due to nocturnal hypoglycemia is a separate pattern (often called the Somogyi effect) and isn’t treated by exercise.