Individuals with diabetes face the challenge of constantly monitoring and managing their blood glucose levels.¹ Various factors that temporarily affect blood glucose levels can add to this challenge, one of which is the dawn phenomenon.²

What is the Dawn Phenomenon?

The “dawn phenomenon” refers to spontaneous episodes of early morning rises in blood glucose levels without preceding low blood glucose levels (ie, hypoglycemia).^2–4 It affects individuals with type 1 and type 2 diabetes mellitus and prediabetes across all ages, with an approximate prevalence of over 50% in the diabetic and 30% in the prediabetic population.^2,5

What Causes It?

The levels of certain hormones (eg, cortisol, growth hormone, and catecholamines) increase at night and stimulate hepatic (liver) glucose production.⁵ In individuals without diabetes, blood glucose and plasma insulin levels largely remain steady overnight due to a transient spike in insulin just before dawn to suppress the increased glucose production, preventing hyperglycemia.^2,3,5 On the other hand, individuals with insulin resistance and/or b-cell dysfunction do not secrete sufficient insulin to suppress hepatic glucose production, resulting in the dawn phenomenon.

Is It Important to Manage It?

It is important to manage the dawn phenomenon as recent evidence suggests that it can affect overall glycemic control and be associated with worsening hemoglobin (Hb) A1c levels overtime.² Minimizing hyperglycemic events and preventing increases in HbA1c levels are associated with decreased diabetes-related complications and risks.

How Can It Be Managed?

Management of the dawn phenomenon should be taken into consideration when discussing your overall diabetes management strategy. An earlier and more aggressive glycemic management may be warranted when the dawn phenomenon is detected, especially if it leads to extended dawn phenomenon, which is hyperglycemia persisting into late mornings.

Comprehensive lifestyle changes are key to type 2 diabetes management. Eating a healthy diet and engaging in morning exercise are recommended.⁶ Your physician may also recommend changes to your insulin regimen to help manage the dawn phenomenon.^2,6