Chronic Somogyi rebound
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The Somogyi effect or Chronic Somogyi rebound is a rebounding high blood sugar that is a response to an initial low blood sugar caused by diabetic hypoglycemia. 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 phenomenon was named after Dr. Michael Somogyi, 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 [1]. Somogyi showed that excessive insulin makes diabetes unstable, and first published his findings in 1938 [2].
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[edit] Background
Typically when a diabetic person is managing their blood sugar with insulin, a shortage of insulin relative to the dose needed will result in hyperglycemia, or high blood sugar levels. Upon detection of hyperglycemia, the typical response of a diabetic person is to deliver a correction dose of insulin to reduce the present blood sugar level, as well as to adjust the insulin regimen to deliver increased levels of insulin in the future to prevent additional hyperglycemia.
However if too much insulin is delivered, the resulting hyperinsulinism will result in diabetic hypoglycemia or a low blood sugar. If undetected for a period of time, the stress due to the 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 to the low level, the physiology of a diabetic person will respond by releasing the endocrine hormone glucagon as well as the stress hormones epinephrine and cortisol. Glucagon will facilitate release of glucose from the liver which raises the blood glucose immediately, and the stress hormones cause insulin-resistance for several hours sustaining the elevated blood sugar condition over time.
The Somogyi effect can easily repeat, since the incorrect increase in insulin delivery due to a perceived high blood sugar will only exacerbate the hypoglycemia and induce another rebound. When this low-high-low-high pattern repeats itself over a period of time, the problem is said to be chronic.
[edit] Detection
Blood sugar levels are monitored from occasional blood droplets or samples from time to time. These "spot checks" of blood sugar levels, usually before meals, are used to adjust the insulin regimen. In this case it is easy for a diabetic person to miss the initial low blood sugar level that was caused by an over-abundance of insulin, but then detect a high blood sugar level later and mistakenly conclude that more insulin is needed. When the hypoglycemia was caused by an over-abundance of insulin in the regimen, then adding more insulin to address the high blood sugar level makes it more likely to cause another episode of hypoglycemia.
The first line of defense in preventing chronic Somogyi rebound is additional blood glucose testing. Continuous blood glucose monitoring would be the ideal method to detect and prevent this, but this technology is not yet widely available due to acceptance in the medical insurance community. Testing blood sugar more often, as much as 8 to 10 times daily with a blood glucose meter, will facilitate finding the low blood sugar levels before the rebound occurs.
Testing occasionally during the middle of the night is also important, at least when high waking blood sugars are found, to determine if more insulin is needed to prevent hyperglycemia, or if less insulin is actually needed to prevent the rebound.
Sometimes a diabetic person will experience the Somogyi rebound when awake and notice symptoms of either the initial low blood sugar (signs of hypoglycemia) or else symptoms of the rebound (signs of adrenaline). At night, waking with a night sweat (perhaps combined with a rapid heart rate), is also a symptom of the adrenaline and rebound.
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.
[edit] Avoidance
In theory, avoidance is simply a matter of preventing hyperinsulinism. In practice however, 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 the occasional over-abundance of insulin.
Some practical behaviors which are useful in avoiding chronic Somogyi rebound are:
- frequent blood glucose monitoring (8 to 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 exaggerated hyperglycemia in response to increased delivery of insulin.
[edit] References
- ^ http://www.whonamedit.com/doctor.cfm/1852.html
- ^ M. Somogyi:Insulin as a cause of extreme hyperglycemia and instability, Weekly Bulletin of the St Louis Medical Society, 1938, 32:498-510
