Different factors are associated with asthma development in males and females at varying ages
(2 July 2005: VIDYYA MEDICAL NEWS SERVICE) -- A study of a large cohort of 1,022 children born in New Zealand who were followed from birth to age 26 revealed that there are different mechanisms associated with the development of asthma at varying ages between males and females.
They found that factors predicting asthma and wheeze differed between the sexes and between childhood and adolescence. In their study, the authors revealed that males more often had childhood wheeze and that females were more likely to display adolescent-onset wheeze.
The researchers pointed out that of the 1,022 study members included in their analysis, 474 were classified, by age 26, as "wheezers," as reported on two or more assessments. Of this group, slightly over 50 percent were male. But among the males who developed wheeze by age 26, 63 percent did so before age 10.
According to data from the study, females who developed wheeze at any age up to 26 had a higher body mass index from age 9 forward. They were also more likely to have had a father with a history of atopy (inherited tendency to allergy), but were less likely to have owned a dog before age 9.
Maternal atopy (either for asthma or hay fever) was a risk factor for childhood wheeze in both sexes. In addition, paternal atopy influenced childhood wheeze significantly for males.
Smoking at age 15 was a risk factor for adolescent-onset wheeze for both males and females. All other risk factors for adolescent-onset wheeze differed between the sexes.
The authors point out that several studies have suggested that female sex hormones influence factors associated with asthma. For example, atopy as measured by skin-prick allergen tests changes during the menstrual cycle. When estrogen levels are high, wheal and flare responses increase. Also, the reaction of peripheral white blood cells to the allergen pokeweed is increased in the presence of estrogen, while testosterone inhibits the response.
The study appears in the first issue for July 2005 of the ATS peer-reviewed American Journal of Respiratory and Critical Care Medicine.
Return to Vidyya Medical News Service for 2 July 2005