Which phenomenon is characterized by progressively elevated blood glucose levels throughout the night?

The dawn phenomenon is characterized by progressively elevated blood glucose levels throughout the night, often reaching their peak in the early morning hours. This occurs due to a combination of factors, including the normal physiological release of counter-regulatory hormones, such as cortisol, glucagon, and epinephrine, which can increase insulin resistance and enhance hepatic glucose production. This natural cortisol surge in the morning tends to occur between 2 AM and 8 AM, leading to higher blood glucose levels upon waking.

In contrast to phenomena like the Somogyi effect, which is related to rebound hyperglycemia following hypoglycemia, the dawn phenomenon is a normal part of the circadian rhythm and does not involve an underlying hypoglycemic episode. Understanding this distinction is crucial as it influences management strategies for diabetes, particularly in patients who experience elevated blood sugar levels in the morning. Monitoring and adjusting medication regimens may help mitigate the impact of the dawn phenomenon on overall glycemic control.