MONDAY, Sept. 26 (HealthDay News) -- Children hit with the double whammy of type 1 diabetes and asthma have an especially tough time keeping their blood sugar under control, a new study finds.
The reason why asthma might complicate pediatric diabetes care remains unclear, however, and is "something that needs to be explored more," said Dr. Anita Swamy, a pediatric endocrinologist and medical director of the Chicago Children's Diabetes Center at La Rabida Children's Hospital in Chicago.
She was not involved in the new study, which appears in the October issue of Pediatrics.
About 215,000 children in the United States have diabetes, according to the U.S. Centers for Disease Control and Prevention. Most children who have diabetes have type 1 diabetes, although type 2 diabetes is becoming more prevalent in kids. Type 1 diabetes is an autoimmune disease that causes the body to mistakenly attack the insulin-producing cells in the pancreas. Insulin is a hormone that helps the body process carbohydrates in food. Type 2 diabetes occurs when the body doesn't produce enough insulin, or when it stops using insulin effectively, according to the American Diabetes Association.
Asthma is a chronic disease that causes inflammation in the airways, and when someone with asthma is exposed to a trigger, the disease causes the muscles in the lungs to tighten, making breathing very difficult. About 7 million American children have asthma, the CDC reports.
According to the new study, which was led by Mary Helen Black of Kaiser Permanente Southern California, about 11 percent of children with diabetes also struggle with asthma. Her team theorized that the inflammation that's present with untreated asthma might make it harder to control blood sugar levels.
The study tracked almost 1,700 children diagnosed with type 1 diabetes and 311 diagnosed with type 2 diabetes between 2002 and 2005, and found that 10 percent of those children with type 1 diabetes and just over 16 percent of those with type 2 diabetes also had asthma.
In kids with type 1 diabetes, the average hemoglobin A1C levels were about 7.5 for children without asthma and 7.8 for those with asthma. A1C is a test that measures long-term blood sugar control. The higher the number, the higher the average blood sugar was. Non-diabetic people generally have an A1C below 6.
Overall, kids with type 1 diabetes and asthma were 37 percent more likely to have poor glycemic [blood sugar] control than to have good control, compared to children without the respiratory ailment. "Among youth with type 1 diabetes, asthma is associated with poor glycemic control, especially if asthma is untreated," the study authors concluded.
However, they did not find a statistically significant link between type 2 diabetes and asthma control. That might be because they had fewer children in the study with both of those conditions, the team suggested.
The use of asthma medications significantly impacted blood sugar control, reported the researchers. Seventy-two percent of children with type 1 diabetes and asthma who were treated with leukotriene modifiers (brand names are Accolate, Singulair, Zyflo) achieved good blood sugar control, according to the study. Leukotriene modifiers are preventive medications that need to be taken every day. They're not available in generic forms.
Still, one expert was skeptical of a true physiological link between asthma and blood sugar control.
"I don't think there's any biology behind this association," said Dr. Juan Celedon, chief of service, division of pediatric pulmonology, allergy and immunology at Children's Hospital of Pittsburgh. Instead, he said, "the ones taking these medications are the ones with better insurance and access to quality health care."
And, that's Celedon's issue with the study as a whole. "My concern is that there is confounding by socioeconomic status and access to health care. They needed to adjust the data for more things. When they adjusted for race and ethnicity, the associations went down. And, children with untreated asthma and poor glycemic control may be the kids who aren't getting adequate health care," he explained.
Swamy agreed, adding, "this is one of those studies that finds an association, but it's hard to know if it's causal. We don't know why they're linked."
In the meantime, she also pointed out that some asthma medications can raise blood sugar levels, which could affect blood sugar control if parents and children aren't aware of that possibility.
Corticosteroids, especially oral steroids, can raise blood sugar levels, though Swamy said recent research has noted a link between inhaled corticosteroids and higher blood sugar levels. Certain asthma rescue medications -- inhaled medications known as beta-agonists -- can also raise blood sugar levels, according to Swamy.
"I tell primary care doctors to let us [endocrinologists] know when a child with asthma and diabetes needs a change in medications. If I know, I can preemptively change the insulin regimen and blood sugar control can still be good. The same goes for when a child has an asthma flare," said Swamy.
She added that parents shouldn't hesitate to call their child's diabetes health care team to find out what changes, if any, need to be made to their child's insulin regimen to account for asthma medications.
Learn more about asthma medications from the American Academy of Allergy, Asthma and Immunology.
SOURCES: Juan Celedon, M.D., chief of service, division of pediatric pulmonology, allergy and immunology, Children's Hospital of Pittsburgh; Anita Swamy, M.D., pediatric endocrinologist, and medical director, Chicago Children's Diabetes Center, La Rabida Children's Hospital, Chicago; October 2011, Pediatrics
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