News Release

News briefs from the journal CHEST, February 2005

Peer-Reviewed Publication

American College of Chest Physicians

Risk Factors Differ for Childhood Asthma and Wheeze, and Bronchial Hyperresponsiveness

Childhood asthma and current wheeze may be associated with different risk factors than bronchial hyperresponsivenes (BHR), according to a new study. Researchers at the David Hide Asthma & Allergy Research Centre, St. Mary's Hospital, Newport, Isle of Wight, UK, compared multiple environmental and genetic factors affecting children at 1, 2, 4, and 10 years of age and whether the children had asthma, wheeze, or BHR when they were 10 years old. Data collected from 1,373 of the original 1,456 children at age 10 showed that 18.9% had current wheeze and 13.0% had asthma, and BHR was found in 169 of the 784 (21,6%) tested. Analysis indicated that both wheeze and asthma share many common significant risk factors, including a genetic link to asthma, a predisposition for being atopic, early exposure to tobacco smoke, and recurrent chest infections in infancy. The only differing risk factor of significance was that males were more likely to have asthma. In sharp contrast, having a higher social class at birth and atopic sensitization at 4 years were found to be the significant risk factors for BHR. These findings suggest that BHR is influenced by mediators that differ from those of asthma and wheezing. The study appears in the February issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians.

Cigarette Smoking and Reduced Lung Function Increases Systemic Inflammation

Low-grade systemic inflammation is associated with health complications, such as cachexia (loss of weight, muscle, and appetite associated with a chronic disease) and cardiovascular mortality and morbidity, and a new study shows that active cigarette smoking and poor lung fuction heighten systemic inflammation, both separately and when combined. Researchers at the University of British Columbia, Vancouver, BC, Canada, administered pulmonary function testing to 7,685 adults ages 40 and over. By using C-reactive protein (CRP) levels as an indication of total system burden of inflammation, researchers were able to determine each individual's amount of systemic inflammation. Results showed that smoking was associated with 1.6 increased odds of elevated CRP levels, a reduction in lung function was associated with 2.3 odds of elevated CRP levels, and for individuals with both risk factors, the CRP odds of elevation of levels increased to 3.3, suggesting an additive relationship. These findings emphasize the importance of smoking cessation in patients with reduced lung function but also indicate that smoking cessation may not be able to fully reduce inflammatory markers to normal levels if lung function is already reduced. The study appears in the February issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians.

Benefits of Inhaled Colistin for Children with Cystic Fibrosis Outweigh Risks

Colistin sulfomethate is being more widely used to treat Pseudomonas aeruginosa infection in patients with cystic fibrosis, but its use is controversial, as some patients experience chest tightness and bronchospasm. Researchers at the Hospital for Sick Children, University of Toronto, Toronto, ON, Canada, administered colistin and placebo (during two separate laboratory visits) to 24 children between the ages of 5 and 18 to see if the subjects would experience negative side effects. Patients experienced a reduction in lung function after inhalation of colistin and placebo, but the drop was greatest for high risk patients with a family history of asthma and/or atopy, bronchospasm due to wheezing, or airway lability who only inhaled colistin. The reduction in lung function for patients without these characteristics was not significant. While researchers were unable to confirm whether the bronchoconstriction was caused by placebo or colistin, those who experienced bonchoconstriction were given salbutamol, which usually reversed their symptoms. Results indicate that bronchoconstriction following inhalation of an aerosol is common but is controllable, and should not deter use of inhaled colistin. The study appears in the February issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians.

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