Overweight girlhood boosts women's asthma risk

Women who were overweight or obese as children face a greater risk of developing asthma as adults, a new study shows.

"Attempts to reduce the burden of excess weight in society must be supported emphasizing the need to focus on children, perhaps young females particularly, in order to prevent asthma," Dr. John A. Burgess of the University of Melbourne in Australia and his colleagues conclude in the European Respiratory Journal.

Among 365 boys and 388 girls who were asthma-free at age 7, women who were in the top 25 percent weight group as 7-year-olds were nearly four times as likely to have asthma at age 32 than their peers in the lowest 25-percent category. However, this relationship between childhood weight and adulthood asthma was not seen in men.

The study participants were enrolled in the Tasmanian Asthma Study, which included 8,583 people and began in 1968, when all were 7 years old.

Women who were obese girls were 3.86 times more likely to develop asthma after age 32 than those who were in the thinnest group as children, the researchers found.

Girls who had been overweight had about triple the risk of developing asthma as adults compared with girls of normal weight. However, after factoring in the effects of other variables, such as smoking and results of lung function tests, this relationship was no longer statistically significant.

Obesity can affect lung mechanics, Burgess and colleagues note. Overweight girls tend to have their first period at an earlier age, suggesting that hormones might also play a role in increased asthma risk.

While the current study found no association between age at menstruation and asthma, they add, the study may not have been large enough to identify such a link.

The researchers also found that women who were heavier at age 32 were more likely to have developed asthma as adults. The study findings therefore suggest that the asthma risk seen at 32 years of age may have started with being overweight as a child, they conclude.

SOURCE: European Respiratory Journal, April 2007.