Low birth weight does not increase risk of asthma in young children

Asthma is a serious condition that affects more than 25.7 million Americans, and is responsible for nearly 4,000 deaths annually. While the cause of asthma remains unknown, a study released today in the January issue of Annals of Allergy, Asthma and Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI), has concluded that low birth weight is not associated with asthma risk in young children.

"Asthma is the most common chronic illness in childhood and is a leading reason for missed school days," said allergist Hyeon Yang, M.D., lead study author. "While environment, genetics, and their interaction are thought to increase one's risk of developing asthma, we now should not assume that low birth weight is associated with asthma. This is an important finding as we continue to understand who is at risk for asthma and why."

Researchers examined a group of children born between January 1, 1976, and December 31, 1979, in Rochester, Minnesota. A total of 3,740 children in the study were born with normal birth weight and 193 children with low birth weight. Of the 193 children born at a low weight, only 13 (6.7 percent) developed asthma, and 201 of the 3,740 children born at a normal weight (5.4 percent) developed the disease.

The study concluded that birth weight did not have any association with a child developing asthma within the first six years of life.

"Asthma is a lifelong disease that is increasing every year within the United States, both by the number of people affected and by cost," said allergist Richard Weber, MD, ACAAI president. "While researchers are still determining what exactly causes the disease, we do know how to effectively treat asthma in children and adults. It is important that those with symptoms see an allergist for proper diagnosis and treatment."

According to the ACAAI, asthma can occur at any age but is more common in children than adults. In young children, boys are nearly twice as likely as girls to develop asthma. Although birth weight is not associated with asthma, obesity is a recently identified risk factor.

Asthma by the numbers:

• Asthma results in 456,000 hospitalizations and 1.75 million emergency room visits annually
• The estimated economic cost of asthma is $20.7 billion annually
• Asthma accounts for 10.5 million missed school days each year
• Patients with asthma reported 13.9 million visits to a doctor's office and 1.4 million visits to hospital outpatient departments
• Improved asthma outcomes with allergists include:
  • 54 percent to 76 percent reduction in emergency room visits
  • 60 percent to 89 percent reduction in hospitalizations
  • 77 percent reduction in lost time from work or school

Source: American College of Allergy, Asthma, and Immunology