Hypoglycemia Poses Risks for Diabetics

Careful monitoring essential to prevent potentially dangerous condition

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HealthDay Reporter

WEDNESDAY, May 26, 2004 (HealthDayNews) --Hypoglycemia, or low blood sugar, is a relatively common side effect of treating type 1 or severe type 2 diabetes with insulin.

The biggest problem is that after hypoglycemia occurs once, the warning signs that normally signal impending low blood sugar are blunted, making people unaware that it's recurring.

In a review article in the May 27 issue of the New England Journal of Medicine, Dr. Philip Cryer, a professor of medicine from Washington University School of Medicine in St. Louis, explained that "hypoglycemia unawareness" occurs because even one episode of hypoglycemia reduces the body's normal defenses against hypoglycemia. This sets up a vicious cycle that can be hard for someone with diabetes to break out of without careful monitoring.

"While there have been steady advances in the management of diabetes, with type 1 diabetes, hypoglycemia is a fact of life," Cryer said.

That's because people with type 1 or severe type 2 diabetes must take insulin to lower their blood sugar, because their bodies can no longer do so on their own. If blood sugar isn't sufficiently controlled, numerous serious complications can occur, such as blindness, kidney failure and heart disease.

But if blood sugar is lowered too much, hypoglycemia results. Symptoms of hypoglycemia include heart palpitations, sweating, hunger, confusion, abnormal behavior and visual disturbances. Left untreated, hypoglycemia can cause a loss of consciousness because the brain needs a constant supply of glucose and can't function properly without it.

Treatment for hypoglycemia is simple, however. Most people with diabetes know to carry glucose tablets or a sweet snack that they can eat quickly to raise their blood sugar if they feel it dropping.

In his article, Cryer explained that once hypoglycemia has occurred, the body reduces the release of the hormone epinephrine during subsequent episodes. This reduces the symptoms that a person with low blood sugar will feel.

Cryer also said that a recent episode of hypoglycemia reduces cognitive function, making it less likely that the person with diabetes can recognize symptoms of low blood sugar.

Fortunately, with careful monitoring, diabetics can break the cycle. According to the article, after two to three weeks with no hypoglycemic episodes, you can improve your awareness of the condition.

"Frequent self-monitoring of blood glucose can help prevent hypoglycemia," Cryer said. Along with regular monitoring, people with diabetes should also check their blood sugar to confirm it actually is low before treating hypoglycemia.

Cryer also noted two special situations where hypoglycemia occurs --during and after exercise and while sleeping.

"If blood sugar is well controlled and you exercise, it can go down even further," Cryer said. He added that while hypoglycemia can occur during exercise, it also can strike hours later and people with diabetes need to be aware of this.

"Sleep does two things to further reduce defenses against hypoglycemia," Cryer said. While sleeping, there's a reduced epinephrine response, which is normally lower in people with diabetes already. Also, diabetics are much less likely to be aroused from sleep by hypoglycemia, he said.

Dr. Bantwal Suresh Baliga, chief of clinical diabetes in the Division of Endocrinology, Diabetes and Bone Diseases at Mount Sinai School of Medicine in New York City, said anyone newly diagnosed with diabetes should undergo diabetes education with a diabetes nurse educator.

Baliga said a nurse educator will teach diabetics strategies for avoiding hypoglycemia. For example, by eating a snack with protein in it at bedtime, you can often prevent hypoglycemia while sleeping. During the day, some people need to have a small snack between meals to keep their blood sugar from dropping too low, he said.

"The gold standard of diabetes treatment is not having hypoglycemic episodes," said Baliga. "Even one episode of hypoglycemia impairs the ability to recognize future episodes."

Like Cryer, Baliga said the best way to prevent hypoglycemia is by monitoring your blood sugar carefully. But, he noted, many people don't like to do this because it requires drawing a small amount of blood from one of the fingers.

More information

To learn more about hypoglycemia and diabetes, visit the National Institute of Diabetes and Digestive and Kidney Diseases or the National Library of Medicine.

SOURCES: Philip Cryer, M.D., professor, medicine, division of endocrinology, metabolism and lipid research, Washington University School of Medicine, St. Louis; Bantwal Suresh Baliga, M.D., assistant professor and chief, Clinical Diabetes, Division of Endocrinology, Diabetes and Bone Diseases, Mount Sinai School of Medicine and chief, division of endocrinology, North General Hospital, New York City; May 27, 2004, New England Journal of Medicine

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