Chronic Somogyi rebound, also called the Somogyi effect and posthypoglycemic hyperglycemia, is a rebounding high blood sugar that is a response to low blood sugar

Diabetic hypoglycemia

Diabetic hypoglycemia is a low blood glucose level occurring in a person with diabetes mellitus. It is one of the most common types of hypoglycemia seen in emergency departments and hospitals...

. In context of managing the blood glucose level manually with insulin injections, this effect is counter-intuitive to insulin users who experience high blood sugar in the morning as a result of an overabundance of insulin at night.

This controversial phenomenon was named after Dr. Michael Somogyi

Michael Somogyi

Dr. Michael Somogyi was an Austro-Hungarian- born professor of biochemistry at the Washington University and Jewish Hospital of St. Louis, who prepared the first insulin treatment given to a child with diabetes in the USA in October 1922...

, a Hungarian-born professor of biochemistry at the Washington University and Jewish Hospital of St. Louis, who prepared the first insulin treatment given to a child with diabetes in the USA in October 1922. Somogyi showed that excessive insulin makes diabetes unstable, and first published his findings in 1938.

Compare with the dawn effect

Dawn effect

Dawn phenomenon is defined as an increase in the blood sugar in the morning and is typically invoked in the context of diabetes. It is different from Chronic Somogyi rebound in that dawn effect is not associated with nocturnal hypoglycemia....

, which is a morning rise in blood sugar in response to waning insulin and a growth hormone

Growth hormone

Growth hormone is a peptide hormone that stimulates growth, cell reproduction and regeneration in humans and other animals. Growth hormone is a 191-amino acid, single-chain polypeptide that is synthesized, stored, and secreted by the somatotroph cells within the lateral wings of the anterior...

 surge (that further antagonizes insulin).

Background

A person with type 1 diabetes struggles to balance insulin delivery to manage their blood glucose level. Occasionally, insufficient insulin

Insulin

Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....

 delivery can result in hyperglycemia

Hyperglycemia

Hyperglycemia or Hyperglycæmia, or high blood sugar, is a condition in which an excessive amount of glucose circulates in the blood plasma. This is generally a glucose level higher than 13.5mmol/l , but symptoms may not start to become noticeable until even higher values such as 15-20 mmol/l...

. The appropriate response is to deliver a correction dose of insulin to reduce the blood sugar level, and to consider adjusting the insulin regimen to deliver additional insulin in the future to prevent hyperglycemia. Conversely, excessive insulin delivery may result in hypoglycemia

Diabetic hypoglycemia

Diabetic hypoglycemia is a low blood glucose level occurring in a person with diabetes mellitus. It is one of the most common types of hypoglycemia seen in emergency departments and hospitals...

. The appropriate response is to treat the hypoglycemia and to consider adjusting the insulin regimen to reduce insulin in the future.

Somogyi and others have claimed that if prolonged hypoglycemia is untreated, then stress due to low blood sugar can result in a high blood sugar level rebound. The physiological mechanisms driving the rebound are defensive. When the blood glucose level falls below normal, the body responds by releasing the endocrine hormone glucagon

Glucagon

Glucagon, a hormone secreted by the pancreas, raises blood glucose levels. Its effect is opposite that of insulin, which lowers blood glucose levels. The pancreas releases glucagon when blood sugar levels fall too low. Glucagon causes the liver to convert stored glycogen into glucose, which is...

 as well as the stress hormones epinephrine

Epinephrine

Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...

 and cortisol

Cortisol

Cortisol is a steroid hormone, more specifically a glucocorticoid, produced by the adrenal gland. It is released in response to stress and a low level of blood glucocorticoids. Its primary functions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat,...

. Glucagon facilitates release of glucose from the liver that raises the blood glucose immediately, and the stress hormones cause insulin resistance for several hours, sustaining the elevated blood sugar.

Detection

The first line of defense in preventing chronic Somogyi rebound is additional blood glucose testing. Continuous blood glucose monitoring would be a far better method to detect and prevent the Somogyi rebound, but the technology is not yet widely available due to acceptance in the medical insurance community. Testing blood sugar more often, 8 to 10 times daily with a traditional blood glucose meter, facilitates detecting the low blood sugar level before such a rebound occurs.

Testing occasionally during the middle of the night is also important, particularly when high waking blood sugars are found, to determine if more insulin is needed to prevent hyperglycemia or if less insulin is needed to prevent such a rebound.

Sometimes a person with diabetes will experience the Somogyi rebound when awake and notice symptoms of the initial low blood sugar or symptoms of the rebound. At night, waking with a night sweat (perhaps combined with a rapid heart rate) is a symptom of the adrenaline and rebound. Unfortunately, the evidence shows that patients with type 1 diabetes do not normally wake during nocturnal hypoglycemic episodes http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371%2Fjournal.pmed.0040069&ct=1.

While reviewing log data of blood glucose after the fact, signs of Somogyi rebound should be suspected when blood glucose numbers seem higher after the insulin dosage has been raised, particularly in the morning.

Avoidance

In theory, avoidance is simply a matter of preventing hyperinsulinism

Hyperinsulinism

Hyperinsulinism refers to an above normal level of insulin in the blood of a person or animal. Normal insulin secretion and blood levels are closely related to the level of glucose in the blood, so that a given level of insulin can be normal for one blood glucose level but low or high for another...

. In practice the difficulty for a diabetic person to aggressively dose insulin to keep blood sugars levels close to normal and at the same time constantly adjust the insulin regimen to the dynamic demands of exercise, stress, and wellness can practically assure occasional hyperinsulinism. The pharmacokinetic imperfections of all current treatment insulin replacement regimens is a severe limitation.

Some practical behaviors which are useful in avoiding chronic Somogyi rebound are:

• frequent blood glucose monitoring (8–10 times daily):
• continuous blood glucose monitoring:
• logging and review of blood glucose values, searching for patterns of low blood sugar values;
• conservative increases in insulin delivery;
• awareness to the signs of hypoglycemia;
• awareness to hyperglycemia in response to increased delivery of insulin.
• use of appropriate types of insulin (long-acting, short-acting, etc) in appropriate amounts

Controversy

Although this theory is well known among clinicians and individuals with diabetes, there is little scientific evidence to support it. Clinical studies indicate that a high fasting glucose in the morning is more likely because the insulin given on the previous evening fails to last long enough. Recent studies using continuous glucose monitoring show that a high glucose in the morning is not preceded by a low glucose during the night. Furthermore, many individuals with hypoglycemic episodes during the night fail to wake due to a failure of release of epinephrine during nocturnal hypoglycemia. Thus, Somogyi's theory is not assured and may be refuted.