Asthma's Course Differs by Gender (HealthDay)

FRIDAY, Aug. 15 (HealthDay News) -- Boys may be more likely to havechildhood asthma than girls, but they are also more likely to grow out ofit, a new study says.

The report, published in the second August issue of the AmericanJournal of Respiratory and Critical Care Medicine, found that boysalso have fewer asthma occurrences in the post-pubertal years.

The study tracked more than 1,000 children, ages 5 to 12, with mild tomoderate persistent asthma over nine years. Each child received an annualspirometric testing with methacholine challenges to quantify their airwayresponsiveness (AR).

After an average of 8.6 years, boys became increasingly tolerant overtime to larger and larger doses of methacholine, which provokes airwayconstriction, suggesting a possible decrease in disease severity. By age16, it took more than twice as much methacholine to provoke a 20 percentconstriction in the boys' airway on average as it did with the girls'.

Over the years, the girls' reactivity did not change markedly. By age18, only 14 percent of the girls showed no significant degree of airwaysresponsiveness, compared to 27 percent of boys.

"While our results were not unexpected, they do point to intriguingpotential mechanisms to explain the gender differences in asthma incidenceand severity. Especially intriguing is that the differences in genderbegin at the time of transition into early puberty," the lead researcher,Dr. Kelan G. Tantisira of Brigham and Women's Hospital and Harvard MedicalSchool, said in a news release issued by the journal's publisher.

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