Decoding The Dawn Phenomenon (Early Morning Increase in Blood Sugar)
blog detail banner


Decoding The Dawn Phenomenon (High Morning Blood Sugar)

Jul 14, 2017

Are your fasting blood sugar levels often higher than when you went to bed? Is high fasting blood sugar with normal PP figures something to worry about? If you are worried about your glucose numbers swinging during sleep or pre-dawn hours, you could be experiencing the Dawn Phenomena.

What Is The Dawn Phenomena?

When we are asleep, our bodies are tasked with repair, maintenance and growth jobs. Since we are not eating anything during sleep, the body uses glucose from the liver to maintain metabolic functions. In addition to that, there is a surge in growth hormones in the early hours of the dawn between 4 am to 5 am, which makes the liver produce more glucose. Fact is; this is a natural occurrence and happens to all of us. In simpler words, everyone has the dawn phenomenon. The body produces hormones, including cortisol, glucagon, and epinephrine, to help maintain and restore cells within our bodies, and also give us the energy we need to start our day and make it until breakfast.

In people who don’t have diabetes, the insulin produced by the body keeps these higher glucose levels in check. However, in diabetics who suffer from insulin resistance or have impaired insulin function, this leads to higher fasting blood sugar levels which normalize only post breakfast. For pregnant women, the dawn phenomenon is even more exaggerated due to additional hormones released in the night.

The body has mechanisms to maintain normal basal glucose levels during sleep, so we don’t get hypoglycemia or low blood sugar at night. In patients displaying impaired glucose tolerance, their body is unable to handle the glucose surge at night combined with the insulin suppression. People who do strenuous exercise early in the morning (e.g. weight training) are also more likely to experience the Dawn Syndrome, due to the peaking of cortisol and growth hormone, both insulin suppressants.

The rise in glucose is mostly because your body is making less insulin and more glucagon than it needs. The less insulin made by the pancreas, the more glucagon the pancreas makes as a result. Glucagon signals the liver to break down glycogen into glucose. This is why high fasting blood glucose levels are common in people with type 2 diabetes. A Chinese research study has also found that poor sleep quality may be associated with Dawn Phenomena, further proving that diabetes and sleep are closely linked.

How to Treat Dawn Phenomenon?

To know if you are experiencing the Dawn Phenomena, it’s important to set your alarm and wake up between 4am and 5am to test your fasting blood sugar levels. If these figures are elevated, do another PP blood sugar test two hours after your breakfast. If you PP blood sugar levels are normal but fasting blood sugar levels are higher, you are experiencing the Dawn Phenomena.

Dawn Phenomena is best addressed as soon as you get the right diagnosis. Failing to address dawn syndrome and extended dawn phenomena can contribute to inadequate overall glycemic control and increase the risk for development or progression of diabetes complications even in the elderly, according to research.

How to treat the high fasting glucose readings caused by the dawn phenomenon? We have found these steps to be helpful:

  • In general, we recommend a LCHF or Low Cab-High Fat diet for all diabetic patients. By eating more of healthy fats and proteins and limiting carbohydrate intake, you minimize the risk of blood sugar levels spiking post meals.
  • Go for a light walk post dinner, as this improves your insulin resistance.
  • If you are hungry later in the night and must have a bedtime, choose a protein/fat snack as opposed to carbohydrates. Nuts, a piece of cheese, or some meat are good options.
  • Talk to your doctor and discuss possible medication/insulin adjustments to control the higher fasting readings.
  • Apple Cider Vinegar supplementation at night has been tried by some to reduce fasting blood sugar, according to a small group study done by Department of Nutrition, Arizona State University. It could work for patients with Dawn Syndrome. Other diabetic supplements like Gymnema Sylvestre, Vitamin B12, Berberine and Green Tea Extract may also be helpful.
  • Eat breakfast to limit the dawn phenomenon’s effect. By eating, your body will signal the counter regulatory hormones to turn off.

Somogyi Effect vs. Dawn Phenomenon

So if you experience higher than normal fasting blood sugar levels, is it always Dawn Phenomena to blame? No, sometimes, it can also be the Somogyi Effect. So what’s Somogyi Effect and how is it different from the Dawn Phenomena? Unlike Dawn Phenomena which is a natural occurrence for everybody, Somogyi Effect usually only affects diabetics who take diabetes management medication or are on insulin.

Somogyi Effect is named after the physician who first described it, and shows a pattern of undetected hypoglycemia (low blood glucose values of less than 70) followed by hyperglycemia (high blood glucose levels of more than 200). Typically, this happens in the middle of the night between 2am and 3am, but can also occur when too much insulin is circulating in the system. The cause of the Somogyi effect is said to be “man-made”—that is a result of insulin or diabetes medication working too strongly at the wrong time.

Excess insulin in the body leads to hypoglycemia and the body releases hormones which cause a chain reaction to release stored glucose. In a state of emergency, the body pulls stored glucose in the liver to normalize glucose levels, which can then swing too high in the other direction, causing hyperglycemia.

Patients who experience the Somogyi Effect may have the usual symptoms of hypoglycemia around 2am, like night sweats and heart palpations. It’s important to note that not everyone experiences these symptoms, as sometimes the body decides that sleep is more crucial, so blood sugar levels quickly rise with the excess glucose pulled out from the liver without any symptoms of hypoglycemia in between.

How to Treat Somogyi Effect?

The only treatment is to prevent the low from happening in the first place. This takes a little detective work to figure out what made the glucose plummet. Talk to your doctor and discuss a change in dosage for your diabetes medication or insulin. For some, insulin pumps can help.

You can also try eating a small protein snack before bedtime, like a piece of toast with peanut butter, or some cottage cheese, or yogurt, or some nuts and a small piece of cheese. As always, a LCHF diet will show significant improvements for all diabetes-related problems.

So Which Do I Have – Dawn Phenomena or Somogyi Effect?

If you have noticed elevated fasting blood sugar levels, you may need to set your alarm and wake up between 2 and 3 a.m. and test your blood glucose. Low blood glucose levels could signify the Somogyi effect is in action. Test again after some time, and if your blood sugar levels are too high, you have a confirmed diagnosis of Somogyi effect. On the other hand, if your blood sugar levels are normal between 2am and 3am and only rise higher between 4am and 5am, you are experiencing Dawn Phenomena.

No matter how we label high glucose values, whether caused by the Somogyi effect or dawn phenomenon, we must figure out their cause. One of the keys of diabetes management is identifying glucose patterns and trends over time. Monitoring is the best way to help solve these situations. Test, don’t guess!

Maneera Saxena Behl
Maneera is a health and fitness enthusiast who is also a firm believer in the power of dietary supplements. A health buff, she likes to help others improve their overall well-being by achieving the right balance between nutrition, exercise and mindfulness.


Vinegar Ingestion at Bedtime Moderates Waking Glucose Concentrations in Adults With Well-Controlled Type 2 Diabetes –

Frequency and Severity of the Dawn Phenomenon in Type 2 Diabetes –

Poor Sleep Quality Is Associated with Dawn Phenomenon and Impaired Circadian Clock Gene Expression in Subjects with Type 2 Diabetes Mellitus –