Type 1 Diabetes Linked to Epilepsy Risk, Study Suggests

But the research did not prove a cause-and-effect connection

Thursday, March 31, 2016

THURSDAY, March 31, 2016 (HealthDay News) -- People who have type 1 diabetes may be nearly three times more likely to develop the seizure disorder epilepsy than people without type 1 diabetes, a new study suggests.

The youngest people with type 1 diabetes -- under 6 years old -- seemed to be six times more likely to develop epilepsy, the researchers reported.

But, those with the highest risk of epilepsy appeared to be children with type 1 diabetes who had to be treated in a hospital for a severe low blood sugar (hypoglycemia). The study found the risk of epilepsy was 16.5 times higher for these children.

It should be noted, however, that the study did not establish a cause-and-effect relationship between the two conditions. And the "absolute" risk of any one person with type 1 diabetes going on to develop epilepsy remains very small.

Epilepsy is a brain disorder affecting less than 1 percent of the U.S. population, according to the U.S. National Institute of Neurological Disorders and Stroke.

"Even though the risk of epilepsy is increased, most type 1 diabetics wouldn't have it," said Dr. Scott Stevens, attending neurologist at Northwell Health's Comprehensive Epilepsy Care Center in Great Neck, N.Y.

Type 1 diabetes is an autoimmune condition that causes destruction of the body's insulin-producing cells. Insulin is a hormone necessary to use the sugars found in foods. To replace the missing insulin, people with type 1 diabetes must take multiple daily injections of insulin or use an insulin pump with a thin tube inserted under the skin to deliver the insulin, according to the American Diabetes Association (ADA).

However, achieving the correct dose of insulin can be difficult. Too little insulin, and high blood sugar results. Over time, high blood sugar can cause serious damage to blood vessels, especially in the eyes, kidneys and heart. Too much insulin also poses a danger, causing low blood sugar levels, which if left untreated can cause unconsciousness and even death, according to the ADA. Previous research has shown that people with type 1 diabetes experience approximately two episodes of low blood sugar each week. Severe hypoglycemia is much less frequent, however.

The researchers aren't sure how type 1 diabetes and epilepsy may be linked.

But study author Dr. I-Ching Chou of China Medical University's Children's Hospital in Taichung, Taiwan, and colleagues suspect a variety of factors may be at play, including immune abnormalities, brain lesions, genetic factors and metabolic abnormalities.

Blood sugar levels that are too high or too low have also been shown to trigger seizures in elderly people, the study authors added.

And previous studies have suggested that having type 1 diabetes at an early age and having severely low blood sugar are critical risk factors for brain abnormalities, the researchers said.

Dr. Gerald Bernstein, an endocrinologist and coordinator of the Friedman Diabetes Program at Lenox Hill Hospital in New York City, said that when people with diabetes don't rigidly control their blood sugar levels, tiny blood vessels in the brain can be affected.

Using data from the Taiwan National Health Insurance Research Database, the study authors pulled records on almost 2,600 children and adolescents with type 1 diabetes, and a comparison group of 26,600 people without a type 1 diagnosis.

Children with type 1 diabetes were about 10 years old, while youngsters in the comparison group were about 11 years old, on average.

Each child in the study group was matched with 10 control-group children for factors including sex, and whether they lived in an urban or rural area.

In kids with type 1 diabetes, the risk of developing epilepsy, after adjusting for other factors that might affect the results, appeared to be 2.84 times higher than in people without diabetes.

Children in the study group with intellectual disabilities were also much more likely to develop epilepsy, the study found.

The study authors acknowledged several limitations with the study. The insurance database, for one, didn't provide information on lifestyle habits, body mass index, physical activity, socioeconomic status and family history. The lack of that information could have skewed the results.

While there may be some connection between type 1 diabetes and epilepsy, the authors concluded that further study is needed.

Based on this study alone, there's no reason to screen every child and adolescent with type 1 diabetes for epilepsy, Stevens said.

"It would create unnecessary stress and unnecessary testing," he said.

What parents should do is advocate for the most contemporary management of type 1 diabetes from its onset, Bernstein added. That includes the use of continuous glucose monitoring and insulin pumps, which insurance doesn't always cover, he said.

With the advantage of those technologies, people might maintain much tighter blood-sugar control over time, he explained.

Findings from the new study were released online March 31 in the journal Diabetologia.

SOURCES: Scott Stevens, M.D., attending neurologist, Northwell Health's Comprehensive Epilepsy Care Center, Great Neck, N.Y.; Gerald Bernstein, M.D., coordinator, Friedman Diabetes Program, Lenox Hill Hospital, New York City; March 31, 2016, Diabetologia, online

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