If you're monitoring your blood sugar, you may have noticed that it rises during the early morning hours before eating or engaging in any activities that typically cause blood sugar spikes. In individuals with diabetes, this phenomenon is known as the dawn effect or the dawn phenomenon. However, it is also being studied in broader populations. In this article, we will explore the physiology of the dawn effect and discuss ways to manage it.
What is the Dawn Effect?
The dawn effect refers to the spontaneous increase in fasting blood glucose that occurs between 3 am and 8 am. It is not directly related to eating, stress, or exercise. People with diabetes, both Type 1 and Type 2, often experience this phenomenon. The rise in blood sugar may continue after breakfast, leading to higher-than-expected levels even after a meal. This is known as the Extended Dawn Phenomenon and serves as a reliable indicator of the dawn effect.
How Common is the Dawn Effect and Who Experiences It?
Early estimates of the prevalence of the dawn effect in people with diabetes varied significantly due to the challenges of identifying blood glucose fluctuations during sleep. With the advent of continuous glucose monitors (CGMs), research on the dawn effect has gained momentum. Recent studies suggest that around 55% of individuals with Type 1 Diabetes and 52% with Type 2 Diabetes experience the dawn effect.
Research on the dawn effect in people without diagnosed diabetes is still emerging. A study in China found that the dawn effect occurs in people without diabetes and in those with impaired glucose regulation, affecting 8.9%, 30.1%, and 52.4% of participants, respectively. The dawn effect may be more common and more pronounced in individuals with impaired glycemic control and higher BMI.
What Causes the Dawn Effect?
The dawn effect is primarily attributed to the secretion of growth hormone (GH) during deep sleep. GH stimulates the liver to release glucose into the bloodstream and decreases the body's sensitivity to insulin, resulting in higher blood sugar levels. Circadian rhythm disruptions and cortisol, a stress hormone that affects insulin sensitivity, may also play a role in the dawn effect, although their significance is still debated.
What Can You Do About the Dawn Effect?
For people with diabetes, managing the dawn effect is essential for overall glycemic control. Strategies include prioritizing sleep, regular exercise to improve insulin sensitivity, avoiding late meals, and reducing carbohydrate intake at breakfast.
The impact of the dawn effect on individuals without diabetes is less clear. Minimizing glycemic variability is generally beneficial for metabolic health. Prioritizing sleep, exercising regularly, avoiding late meals, and choosing low-carbohydrate breakfast options may help regulate blood sugar levels.
Conclusion:
The dawn effect is a common occurrence, particularly in individuals with diabetes. Its main cause is the secretion of growth hormone during sleep. Although research on the dawn effect in non-diabetic individuals is still in its early stages, adopting healthy lifestyle habits may help manage blood sugar levels effectively.
