FLORENCE, ITALY--Nasal swabs may be better than nasal lavage for obtaining samples of the respiratory tract lining fluid in infants with bronchiolitis, researchers reported at the joint meeting of the World Congress on Lung Health 2000 and the 10th Annual Congress of the European Respiratory Society. Other highlights of the meeting included a warning that estrogen use may cause asthma and that marathon runners are at increased risk of asthma.

INTENSIVE EXERCISE IS BAD FOR THE LUNGS

Long-distance runners are more than three times as likely as the general population to suffer from asthma, according to Professor Kai-Håkon Carlsen and colleagues from the Voksentoppen Children's Asthma and Allergy Center in Oslo, Norway.

Of the 58 marathon runners surveyed, 15 (26%) exhibited signs of seasonal bronchial contraction either in the spring because of pollen allergy or in the winter because of cold weather. The same research group confirmed the findings in another study involving 71 long-distance runners.

ESTROGEN USE LINKED TO ASTHMA

Women who use oral contraceptives or hormone replacement therapy containing estrogen are significantly more likely to have asthma than are women who do not take estrogen, new findings suggest.

Jan Parner and colleagues from the University of Copenhagen in Denmark studied data from 5,576 women enrolled in the Copenhagen City Heart Study. Of this group, 1,085 women used oral contraceptives or postmenopausal estrogen therapy.

Overall, 6.7% of the women who used estrogen were diagnosed with asthma, 36.4% reported wheezing, 17.6% had exercise-induced cough, and 6.7% used asthma medications. Treatment with estrogen was associated with a higher prevalence of all four of these factors (Table 1).

BIOSTIMULATION TREATS LUNG CANCER PAIN

Biostimulation of acupuncture points lowered the intensity of pain in patients with lung cancer, reported V. Kuruc of the Institute of Lung Diseases in Sremska Kamenica, Yugoslavia.

The study involved 21 lung cancer patients whose pain was not adequately controlled with oral or parenteral analgesics. The patients were asked to rate the intensity of their pain on a scale of 1 to 10 before and after 10 days of treatment with biostimulation. The treatment involved use of laser or needle acupuncture at classic acupuncture points.

Before treatment, most of the patients reported intense pain (average pain score, 8.33). However, none of the patients reported intense pain after treatment, and the average pain score decreased to 2.57. The pain intensity was highly correlated with treatment duration, confirming that the longer the treatment, the lower the pain intensity.

MONITORING OF RSV BRONCHIOLITIS

Samples of respiratory tract lining fluid collected by nasal swab are more accurate and easier to obtain from infants with respiratory syncytial virus (RSV) bronchiolitis than are samples taken by nasal lavage, according to researchers from the University of Sheffield, in the United Kingdom.

J. M. Bhatt et al used nasal swabs and nasal lavage to obtain samples of the respiratory tract lining fluid from 11 infants with RSV bronchiolitis. Nasal lavage samples were collected using normal saline and centrifuged at 1,000 rpm. A cotton bud, moistened with sterile saline, was used to swab each nostril and was then centrifuged at 2,000 rpm. Protein concentration and secreted myeloperoxidase were measured in the supernatant obtained by each method.

The mean amount of myeloperoxidase was more than 12 times higher in the samples collected by nasal swab than in samples collected by nasal lavage (0.86 X 10⁶ mL vs 0.07 X 10⁶ mL, respectively). Similarly, the mean concentration of protein in the nasal swab samples was almost 13 times higher than that in the nasal lavage samples (3.6 mg/mL vs 0.28 mg/mL, respectively). The researchers noted that the infants experienced little discomfort from the nasal swab and that the procedure was easy to perform. In addition, the children's parents preferred the nasal swab procedure over nasal lavage.

GENDER DIFFERENCES IN REACTIONS TO SMOKING

Women are twice as likely as men to suffer from chronic obstructive pulmonary disease. The findings, which are based on a study involving 10,000 people, were reported by Dr. Eva Prescott of the Institute of Preventive Medicine at the Kommunehospitalet in Copenhagen.

In addition to hormonal influences, the gender difference may be caused by an anatomic factor: Because women have smaller lungs, they have a greater exposure to smoke per unit of area, Dr. Prescott noted. "A greater susceptibility to bronchoconstriction has also been suspected among women," she added.

In a related study, Cecilie Svanes, MD, found that passive exposure to smoke is more harmful for boys than for girls. Data from the European Community Respiratory Health Survey showed that the risk of wheezing in adulthood was increased by 15% to 30% among boys (but not girls) who lived with a smoker during childhood.

"This difference could be due to a higher sensitivity to damage by exposure to tobacco smoke in males with less mature lungs than females very early in life," said Dr. Svanes, of the Department of Thoracic Medicine at Haukeland Hospital in Bergen, Norway.

DO ALLERGENS CAUSE ASTHMA?

Allergen exposure is not a primary cause of asthma in children, according to a literature review reported by Professor Neil Pearce and colleagues from the Wellington Asthma Research Group in New Zealand.

The analysis was designed to test the hypothesis that the global increase in asthma prevalence is the result of increased exposure to aeroallergens. The researchers found no randomized studies showing a relationship between asthma risk after age 6 years and allergen exposure during infancy.

Many population-based studies have shown negative associations between allergen exposure and current asthma. In fact, the average risk of asthma attributed to allergens was 4% for dust mites, 11% for cats, -4% for cockroaches, and 6% for dogs. Allergen avoidance measures did not alter these risks significantly.

"Furthermore, evidence from population studies is equivocal and provides little consistent evidence that allergen exposure is associated with the prevalence of asthma at the population level," the researchers noted. Their findings were also published in the May issue of Thorax.

--Kristin Della Volpe

Return to table of contents