- Children exposed to higher levels of cockroach, mouse and cat allergens at home during infancy are at lower risk for developing asthma by seven years of age
- More than eight percent of children have asthma, in the United States
- Developing strategies can help prevent asthma and alleviate the burden of the disease
Children exposed to higher levels of pet or pest allergens at home during infancy were found to have a lower risk of developing asthma by seven years of age, reveals a new study conducted by the National Institutes of Health.
The results published in the Journal of Allergy and Clinical Immunology provide clues to design the strategies that can aid in preventing the development of asthma.
In previous studies, reducing allergen exposure in the home can aid in controlling the development of asthma.
In this study, the findings showed that being exposed to certain allergens very early in life, even before asthma could develop might have a preventive effect.
The findings are from the ongoing Urban Environment and Childhood Asthma (URECA pronounced "Eureka") study. The study is being funded by NIH's National Institute of Allergy and Infectious Diseases (NIAID) through its Inner-City Asthma Consortium.
Anthony S. Fauci, M.D, NIAID Director stated that they are progressively learning about how the early-life environment could influence the development of certain health conditions.
Anthony S. Fauci said, "If we can develop strategies to prevent asthma before it develops, we will help alleviate the burden this disease places on millions of people, as well as on their families and communities."
Currently, more than eight percent of children have asthma in the United States, according to the Centers for Disease Control and Prevention.
What is Asthma?
Asthma is a chronic disease that frequently inflames and narrows the airways and can result in missed time from school and work. It is one of the leading causes of an emergency visit and hospitalization.
The URECA study examined the risk factors for asthma among children living in urban areas, as the disease was found to be more prevalent and severe.
About 560 newborns from Baltimore, Boston, New York City and St. Louis who are at high risk for developing asthma have been enrolled in URECA since 2005. It was also found that at least one parent has asthma or allergies.
The children were being followed since birth by the research team, and the current study evaluated the group through seven years of age.
The research team had enough data to assess asthma status of children who were seven years old. Among 442 children, 130 children (29%) were found to have asthma.
Findings of the study
During the first three years of life (at age three months, two years and three years), children exposed to higher concentrations of cockroach, mouse and cat allergens that were present in dust samples at home lowered asthma risk by the time children were seven years.
The research team observed a similar association for dog allergens. Though the results found were not statistically significant.
Also, additional analysis showed that being exposed to higher levels of these four allergens at age three months was found to be associated with a lower risk of asthma development.
The evidence gained by the research team showed that the microbial environment in the home's of children during their infancy might be linked with asthma risk.
In the previous report from URECA, assessing the microbiome of house dust, which was collected in the first year of life showed that exposure to certain bacteria during infancy might protect 3-year-olds from reoccurring wheezing, as it is a risk factor for developing asthma.
The abundance of certain types of bacteria in the house dust was found to be linked with asthma diagnosis by age seven years in this study indicate that exposure to certain types of bacteria early in life might influence asthma development.
Further research is required to clarify the potential roles of these microbial exposures in the development of asthma.
Further Research Needed to Develop Preventive Strategies
James E. Gern, M.D., the principal investigator of URECA and a professor at the University of Wisconsin-Madison said, "Our observations imply that exposure to a broad variety of indoor allergens, bacteria, and bacterial products early in life may reduce the risk of developing asthma."
Further research can help the research team identify specific targets for preventing asthma.
The results of seven-year URECA confirms the previous studies that are linked to the development of childhood asthma to recognized risk factors like prenatal exposure to tobacco smoke, maternal stress, and depression.
The research team also found that the presence of cotinine in the umbilical cord blood of newborns that results from the breakdown of nicotine in the body increases the risk of developing asthma by age seven years.
Maternal stress and depression during the first three years of the child's life were also found to be linked with a higher risk of developing childhood asthma.
The URECA scientists are continuing to invigilate the children by dividing them into groups based on their characteristics of allergies and asthma.
Scientists hope to discover further information about which early-life factors influence the development of allergic or non-allergic asthma.