Dawn Phenomenon

Submitted by Thiruvelan on Fri, 11/16/2012
Diabetes Dawn Phenomenon

Early morning blood sugar rises immediately before or after waking is known as dawn phenomenon. It is normal phenomenon both among diabetes and nondiabetes.

You know, how bad dawn phenomenon is? Now you can learn, how much it impacts your A1C levels? How to prevent it?

Dawn Phenomenon?

What is dawn phenomenon? Dawn phenomenon is a normal physiological process at dawn (early morning around 4 a.m.) during which certain hormones in your body work to raise your blood glucose level to prepare you to wake up. The hormones involved in the dawn phenomenon are cortisol, glucagon, epinephrine, and growth hormone. These hormones are called counter-regulatory hormone because they work against the action of insulin. It causes the liver to release glucose to a healthy individual and the liver dump glucose in people with diabetes. Results in an increase in blood glucose levels, which is normalized in nondiabetic and not in case of diabetic called as dawn phenomenon. The circadian rhythm creates this phenomenon.

In healthy, nondiabetic individuals the blood glucose and plasma insulin level remains constant overnight. However, with modest raise in insulin secretion just before dawn to control hepatic glucose production and to prevent hyperglycemia. That is why, healthy individuals do not exhibit the dawn phenomenon, because of proper insulin secretion to prevent it.

Dawn Phenomenon (DP) was first described 30 years ago. Prevalence is estimated to be over 15 % in both type 1 & type 2 diabetes, although severity varies widely from person to person. The circadian rhythm is behind this phenomenon.

Around 4 am, you will soon go to wake up; your body prepares you for the upcoming day by releasing certain hormones such as cortisol, glucagon, epinephrine, and growth hormone. These hormones are called counter-regulatory hormones because it raises your blood glucose level. Your body raises insulin secretion, to prevent the sugars from rising too much.

The dawn phenomenon effect on people with diabetes varies; some affected most with very high morning blood sugar level and others less affected with marginal BS rise. Additionally few people with diabetes find their blood glucose rises continuously until they ate something in the morning. For others, the level managed to settle down after few hours of waking, regardless of whether they eat or not.

How counter-regulatory hormone raises blood sugar? Glucagon tells the liver to start pushing out some glucose. Adrenalin gives our bodies some energy. Growth hormone is involved in repair and new synthesis of protein. Cortisol, the stress hormone increases as a general activator. So these hormones work together to raise blood sugar and gently get you ready to wake up.

Insulin secretion increases in the early morning to counteract the counter regulatory hormones. In a healthy individual, insulin is there to make sure blood sugars do not go too high. However, if you look closely at the blood sugar readings, there is a slight increase in the morning time.

What will happen during dawn, if you are T2D? Around 4 am, counter regulatory hormones surge and insulin is also released to counter this. However, in case of insulin resistance, insulin has minimal effect at lowering the blood sugars. Additionally, the counter regulatory hormones are still working, blood sugars rise unopposed, and therefore much higher than the normal nondiabetic situation.

In T2D, high fasting blood glucose is due to the transient rise in hepatic glucose production by glycogenolysis and gluconeogenesis during dawn with the absence of compensatory insulin secretion. A study observed an increased interstitial glucose (IG) concentration from night to before breakfast are about 13 to 20 mg/dL, this extends to post breakfast with the highest values 191 to 208 mg/dL. The dawn phenomenon has an impact on the mean daily IG and A1C.

What will happen during dawn, if you are T1D? Around 4 am, counter regulatory hormones surge and there is minimal insulin action exist. There is minimal insulin action at lowering the blood sugars. Additionally, the counter regulatory hormones are working to raise blood sugars unopposed, which is much higher than the normal nondiabetic situation.

A T1D study shown insulin sensitivity is higher in the midnight to 3 a.m. as compared to 4 a.m. (dawn) to 8 a.m. Another dawn phenomenon study shown better glycemic control is possible with continuous insulin infusion (using an insulin pump) as opposed to long-acting formulations. The continuous insulin infusion along with a bolus in the early morning can counteract the dawn phenomenon. Using an insulin pump, you can program the pump to increase your insulin during dawn phenomenon.

How is it possible to have a high fasting number without eating anything in the previous night? Your liver stores excess of glucose and fat for future use. During fasting your blood glucose drops, your liver responds to this by releasing stored glucose into the bloodstream. The hormones growth hormone, cortisol, glucagon and adrenaline level rises during dawn. Thus your body is less capable of moving the glucose from your blood stream into the cells. These factors combine to make your blood-glucose shots up even without food the previous night.

How do I distinguish between Somogyi effect and dawn phenomenon? Both have high fasting blood sugar that is why this confusion. No problem, you have to wake up at 2 to 3 a.m. to test your blood glucose level. If the blood glucose level is consistently normal or high, then it may be dawn phenomenon. If the blood glucose level is low, then it may be Somogyi effect.

Dawn phenomenon symptoms and diagnosis

What are the symptoms of dawn phenomenon? Symptoms of the dawn phenomenon include nausea, weakness, and extreme thirst roughly between 4 and 8 a.m. If you have a consistently high blood glucose level in the morning may indicate dawn phenomenon.

How much is blood glucose rise called dawn phenomenon? Blood sugar level rise during dawn phenomenon varies tremendously from person to person and from time to time. Early studies suggested an increase of 10 mg/dl as the threshold. But recent studies recommend 20 mg/dl rise in the threshold based on the average rise in diabetes.

How much effect dawn phenomenon makes on your A1C? Dawn phenomenon can increase your A1C by up to 0.39 %. For example, if you have dawn phenomenon and your A1C is 7 %, then you would get an A1C of 6.61 % (7.00 – 0.39=6.61) if you can manage DP.

Dawn phenomenon treatment and prevention

For some people with diabetics, may find difficult to manage their dawn phenomenon. Such individuals may need to modify their treatment to counteract dawn phenomenon.

You can treat dawn phenomenon by changing the medication timing, lower carbs, early dinner, and physical activity.

What can you do to avoid the Dawn Phenomenon? Get the excess sugar out of the liver, and improve insulin sensitivity. Ok, how do you do that? Reduce your carb; specifically eliminate sugar, sugary drinks, potato chips, white flour (white bread, pasta, etc.), and other refined & packed foods. An LCHF diet or intermittent fasting… Or preferably both.

  1. Carbohydrate – Avoid carbohydrates around bedtime; instead, take protein and fat rich snacks. Reducing incoming glucose is the obvious first step, at least on the carb. Cut down in carb in the dinner or before bedtime can help lower fasting blood sugar level. Even some diabetic claim that after they stop drinking a glass of milk before bedtime helps them a lot.  Alternatively, you can take grass fed whole milk instead of skimmed milk. Some people with diabetes claim, cutting down all carbs after 12 noon has helped a lot.
  2. Time - Eating dinner earlier in the evening. Take medication or basal insulin closer to bedtime and not at dinner time. Taking breakfast in time without skipping is also considered to be important.
  3. Exercise – Being inactive is detrimental to your health is all means. Doing some exercise is better than nothing. No matter what kind of exercise you do, physical exercise of any form enhances the body’s response to insulin and improves insulin sensitivity.  Weight training can dramatically improve your fasting blood glucose.
  4. Walk after dinner - After dinner does some light physical activity, such as going for a walk has a wonderful effect on your blood glucose level both after-meal and fasting.
  5. Weight loss – Losing weight helps to normalize hormonal disturbances, better insulin sensitivity, and lower blood glucose (both fasting and postprandial). You would often experience blood glucose drop before there is any pound loss.
  6. Vinegar might be useful for dawn phenomenon; you can take it as tablets or 1 or 2 teaspoons diluted in a glass of water. Preferably take it immediately before your food, why? It is an acid that can hurt your esophagus; however, when you take it immediately before food then it will not hurt instead of help proper digestion and assimilation. Many people with diabetes need 4 to 6 vinegar tablets with dinner or at bedtime to avoid morning spikes. Vinegar also showed to reduce insulin resistance.
  7. Green apple - According to John Walsh and Ruth Roberts author of “Stop the Rollercoaster: How to take charge of your blood sugar in diabetes” suggest to eat a green apple at bedtime to lower your fasting blood sugar. It worked for many people with diabetes, try your luck hope it helps.
  8. Red wine - Drinking red wine before bedtime works to counteract the dawn phenomenon in many diabetic individuals. It seems to work well when you drink it around 10 pm.
  9. Caffeine - Some diabetic claim their DP went down just by cutting back their caffeine intake, may be due to lowering of adrenal secretion.

For type 2 diabetes - Even with combinational oral medications, it is not possible to control the dawn phenomenon. According to the new study using basal insulin at bedtime could help dawn phenomenon. Basal insulin includes Lantus and Levemir; they give you long-acting insulin for as much as 24 hours. You may adjust your dose and timing so that peak action occurs closer to the dawn (early morning) rise in your blood glucose.