April 2008

Spring Bulletin Online Now
The Spring edition of our Section Bulletin is online now, so visit the SECTION WEB SITE to read all about our new editor, Russell L. Harris, plus great articles on biologic and mechanical quality control testing, and calibration versus quality control.

Study Questions ATS Standard
German researchers find the American Thoracic Society (ATS) standard protocol using a heart rate formula for assessing exercise intensity is not sufficient to cause predominantly anaerobic lactate metabolism and therefore an exercise-induced hyperventilation. The study was conducted among 100 healthy non-asthmatic sports students who underwent an exercise challenge test for bronchial provocation on a treadmill ergometer according to the ATS standards. Results were as follows:

• After exercise, lactate concentrations in 56% of the examined subjects were lower than 6mmol/l.
• A highly significant decrease in FEV1 (-4.41+/-1.5%) was found at concentrations of more than 6mmol/l, whereas at concentrations below 6.48mmol/l no test person showed an impairment of lung function with FEV1 values declining below 90%.
• In five subjects a bronchial obstruction was found, as shown by decreases in FEV1 of -10 to -47% after exercise. The lactate concentrations in these individuals were between 6.48 and 11.7mmol/l, indicating a predominantly anaerobic metabolic response to exercise.

The study was published in the March 4 Epub edition of the British Journal of Sports Medicine. READ ABSTRACT

Task Force Recommends Against Routine Spirometry to Screen for COPD
The U.S. Preventive Services Task Force has recommended against using spirometry to test asymptomatic adults for COPD. According to the report, about 400 adults between the ages of 60-69 would need to be screened in order to identify a single patient who may later develop COPD symptoms severe enough to require immediate medical care. The analysis also showed spirometry can substantially over-diagnose COPD in people over the age of 70 who have never smoked, and can produce some false positives in younger adults. The recommendations were published in this month’s Annals of Internal Medicine. READ PRESS RELEASE READ RECOMMENDATIONS

FENO Effective in Measuring Respiratory Symptoms
A new study out of Portugal suggests exhaled nitric oxide (FENO) is a good measure of respiratory symptoms in young children. Researchers compared children with and without a history of wheezing in the previous 6 months. All underwent standard pulmonary function tests and filled out questionnaires on their respiratory symptoms. The median FENO was 27 ppb versus 11 ppb, respectively, for children who did and did not need a bronchodilator in the previous 6 months. Significant differences were also seen in median FENO levels among children who did and did not need an unscheduled medical appointment in the six months prior to the evaluation, 28 ppb versus 13 ppb, respectively. The report appeared in the March/April edition of Revista Portuguesa de Pneumologia. READ ABSTRACT

Prolonged Obesity More Likely to Affect Pulmonary Function
Harvard researchers are shedding new light on the role of diet-induced obesity on pulmonary function. Building on previous research that showed genetically obese mice exhibit innate airway hyperresponsiveness (AHR), they set out to gauge respiratory status in mice that become obese through a high fat diet. The study compared mice who were fed diets with either 60% fat or 10% fat from weaning until at least 30 weeks of age. Mice on the high fat diet had a 40% greater body mass and larger baseline AHR to intravenous methacholine, measured by forced oscillation. O3-induced increases in bronchoalveolar lavage fluid protein, IL-6, KC, MIP-2, IP-10, and eotaxin were greater in these mice as well. However, innate AHR and augmented responses to O3 were not observed in mice raised on the high fat diet from weaning until 20-22 weeks of age, leading the investigators to conclude the adverse pulmonary effects only become apparent with prolonged obesity. The study was published in the March 6 Epub edition of the Journal of Applied Physiology. READ ABSTRACT