Very low blood sugar affects memory in children
Episodes of extremely low blood sugar (Hypoglycemia), particularly at an early age, can have an impact on spatial memory performance in children with Type 1 Diabetes, according to the results of a new study.
As lead investigator Dr. Tamara Hershey said, “this study tests and supports a common hypothesis that severe Hypoglycemia experienced early in life is riskier for cognitive function than severe Hypoglycemia experienced later in life. We focused only on a spatial memory task which has previously been shown to be sensitive to repeated Hypoglycemia.”
Hershey, of Washington University School of Medicine, St. Louis, Missouri, and colleagues studied data from three independent studies involving 103 diabetic children and 60 children without diabetes between 6 and 18 years old. The findings are published in the journal Diabetes Care.
Hypoglycemia occurs when your body’s blood sugar, or glucose, is abnormally low. The term insulin shock is used to describe severe hypoglycemia that results in unconsciousness.
Causes, incidence, and risk factors
Hypoglycemia results when your body’s glucose is used up too rapidly, when glucose is released into the bloodstream more slowly than is needed by your body, or when excessive insulin is released into the bloodstream. Insulin is a hormone that reduces blood glucose. It is produced by the pancreas in response to increased glucose levels in the blood.
The 2-hour battery of cognitive measures included evaluation of short (5-second) and long (60-second) spatial memory and reactions. This involved recalling locations and responding to shapes shown on a computer screen.
Children who had had more than three episodes of severe Hypoglycemia showed reduced performance on the longer-delayed spatial response test. This was particularly the case when severe hypoglycemic episodes began before the age of 5 years.
The age at which Type 1 Diabetes developed and estimates of chronic high blood sugar levels did not influence performance.
Type 1 diabetes mellitus, more commonly known as type 1 diabetes, is a disease in which the pancreas produces too little insulin to meet the body’s needs. Insulin is a hormone that helps control the level of glucose in the blood. Glucose is the main form of sugar in the body.
What is going on in the body?
Glucose is a key source of energy for the cells of the body. When a person eats, the pancreas makes extra insulin to move glucose from the bloodstream to the inside of the cells, where it is converted to energy. A person with type 1 diabetes does not make enough insulin to move the glucose into the cells. As a result, the amount of glucose in the blood becomes too high. This condition is called hyperglycemia, and it can cause damage to the body, if left untreated.
For more information check: Type 1 Diabetes
The researchers conclude that “the developing brain of very young children may be more vulnerable than the brain of older children to the negative effect of severe Hypoglycemia on longer-term spatial memory.”
However, Hershey added that “more research needs to be done on how this effect relates to everyday life. This information could eventually be used when assessing the benefits and risks of tight (sugar) control…at very young ages.”
SOURCE: Diabetes Care, October 2005.
Revision date: July 8, 2011
Last revised: by Sebastian Scheller, MD, ScD