When your blood sugar levels are elevated in the morning, it’s commonly referred to as the “dawn phenomenon” or the “dawn effect.” This natural occurrence tends to happen between 3:00 a.m. and 8:00 a.m. and affects individuals with both type 1 and type 2 diabetes. Let’s explore the reasons behind it: The Dawn Phenomenon: During the early hours of the morning, hormones like cortisol and growth hormone signal the liver to produce more glucose, providing energy to help you wake up. In response, beta cells in the pancreas release insulin to regulate blood glucose levels. However, if you have diabetes, your body may not produce enough insulin or may be resistant to it, leading to elevated blood sugar upon waking. Approximately half of people with diabetes experience the dawn phenomenon. Waning Insulin: If your insulin levels drop too low overnight, your blood glucose rises. Reasons for this insulin drop vary, such as inadequate basal insulin settings or insufficient long-acting insulin doses. The duration of insulin action also

matters; if injected too early, it may not last until morning. The Somogyi Effect: Named after chemist Michael Somogyi, this rare effect occurs in response to low blood glucose (hypoglycemia) during the night. Imagine missing dinner or taking too much insulin after your evening meal. Your blood glucose may plummet overnight. In compensation, your body produces more glucose, resulting in high blood sugar upon waking. What Can You Do? Gather Clues: Monitor your blood glucose levels at bedtime, during the night, and upon waking to understand your patterns. If you use a continuous glucose monitor (CGM), it can collect data while you sleep. Identify the Culprit: Analyze when your highs occur. If they happen at bedtime, consider food and medication. If you experience high blood glucose before sleep, it may persist until morning1. Remember, occasional morning highs have minimal impact on your A1C (average blood glucose levels over time). However, consistent highs can be concerning. Consult your doctor if you notice a pattern of elevated morning blood sugar levels.