ASTHMA WATCH

Indoor Swimming Pools Are a Risk for Asthma

Indoor swimming pools may be blamed for the increase in asthma in European children. The researchers looked at the rates of asthma in 13-and 14-year-old children in 21 European countries and the number of chlorinated swimming pools per 100,000 individuals.

The study results showed that childhood asthma and wheeze increased by 2% to 3% for every indoor swimming pool. The researchers found that the rate of wheezing increased by 3.4% and asthma by 2.7% for every additional indoor chlorinated swimming pool. The investigators recommended additional research on the impact of chlorinated swimming pools and asthma risk and improved ventilation of indoor pools. (The findings were recently published in Occupational and Environmental Medicine.)

Women Cease Asthma Therapy During Pregnancy

A new study has uncovered that many women considerably reduce the use of asthma medications in the beginning of pregnancy. The decision places mothers and their infants at risk because national treatment guidelines recommend the continued use of these drugs. For the study, the researchers used data from >8000 pregnant women with asthma who were participating in the Tennessee Medicaid program to investigate whether women modify their use of asthma medications during pregnancy.

The researchers found that at 13 weeks of pregnancy the use of inhaled anti-inflammatory medications had dropped by 22.9%; the use of shortacting beta-agonists had decreased by 13.2%; and the use of rescue corticosteroids had fallen by 54.3%. Furthermore, the use of all classes of asthma medication increased from weeks 6 to 13 and from weeks 13 to 26 of pregnancy. Only the use of short-acting beta-agonists, however, showed a statistically significant rebound by week 26, noted the researchers in the July 2006 issue of the American Journal of Obstetrics and Gynecology.

"Both primary care physicians, as well as providers that care for women during pregnancy, should educate women early and frequently about the importance of continuing to control their asthma and ensure that they are using appropriate medication," explained study investigator Tina V. Hartert, MD, MPH.

Throw Away the Cigarettes

Individuals with asthma who kick smoking can attain a >15% improvement in lung function tests in <2 months, according to a study reported in the American Journal of Respiratory and Critical Care Medicine (July 2006). The study involved 21 smokers with asthma, aged 18 to 60, who had beginning lung function score results of <85% of their predicted level. During the study, 10 of the participants stopped smoking for 10 weeks, and the 11 other participants continued the habit.

The researchers found that after 1 week without cigarettes the lung function test results of the nonsmokers had a "considerable degree" of improvement. "The improvement in lung function seen after smoking cessation was clinically significant. It demonstrates that there is a reversible component to the harmful effects of smoking on the airways in asthma," said researcher Neil C. Thomson, MD.

Air Pollution Bad for Children's Lung Function

Researchers have found that air pollution (ie, carbon particles from motor vehicles) works it way into children's airways and weakens their lung function, according to a study reported in the New England Journal of Medicine (July 6, 2006). The study of 114 healthy children showed a 13% reduction in children's "forced vital capacity" ?a measure of lung function?for every 1 micrometer-squared increase of carbon content in their lungs. For the current study, the participants were aged 8 to 15, had normal levels of physical activity, and had been residing in their current homes for at least a year.

The participants had sputum samples collected and their lung function tested using spirometry. The researchers were able to obtain sufficiently sized samples from 64 of the children. The sputum samples were tested to measure the carbon content. The results indicated that, for each 1-micrometer-squared increase in carbon content, there was a 17% lower rate of forced expiratory volume in 1 second and a 13% reduction in forced vital capacity.

The association proved valid even after the researchers considered exposure to secondhand smoke, body mass index, and gender. To guarantee that lower lung function was not responsible for an increase in carbon deposits, the researchers also measured carbon content found in the lungs of 9 children with asthma. The researchers were surprised to find less carbon in the lungs of children with asthma. Lead investigator Jonathan Grigg, MD, said that the team suspected this outcome may be because individuals with asthma may process inhaled particles differently, compared with individuals with healthy lungs.