To add to another of the long list of woes that being overweight can cause, New Zealand scientists are now adding asthma to
the list for some overweight teenage girls and young women.
University of Otago scientists have found that gaining too much weight in the late teens and early adulthood was “significantly associated” with asthma wheeze in women. The researchers estimate that 28 percent of new asthma cases in girls and women age more than 9 years old are due to being overweight.
Asthma is a huge problem here and around the world— the World Health Organization estimates between 100 and 150 million people worldwide suffer from asthma; in New Zealand, it’s 15 to 20 percent of the population.
For the asthma study, the researchers tested a large group of children at ages 9, 11,13, 15, 18, 21, and 26. At age 9, there was no evidence of an association between being overweight and asthma in females, but by 26 it was statistically significant.
At each interval, the researchers checked on whether the children had had asthma symptoms and took measurements of lung function, airway responsiveness. The inherited tendency toward allergic reaction was also discussed at each meeting.
The investigators also calculated the young person’s age, height, and weight in light clothing without shoes to determine their body mass index (BMI). The association between raised BMI and asthma appeared to emerge in late adolescence, according to the investigators.
“Our findings confirm and extend those of many studies that have reported an association between BMI and asthma in women. We found no association between a raised BMI and asthma in children; the association appeared to emerge in late adolescence,” the scientists write in the report of their findings published in the American Journal of Respiratory and Critical Care Medicine.
The scientists did not find any link between asthma and the onset of puberty, nor did the onset of puberty change the relationship between BMI
and asthma. They also found that already having asthma and then putting on weight in puberty did not appear to cause relate to asthma and being overweight in adulthood. Those who had already developed asthma by age 9 tended to have lower BMIs as adults.
But the researchers did find a link to family history. By analyzing the relationship between estimated BMI and reported asthma
in the parents of the study members, the researchers showed a significant association between asthma and BMI in the mothers of the study members, but not in their fathers. “This indicates that the association between BMI and asthma been stable across
two generations of New Zealand women,” the researchers said.
For males, it doesn’t seem to be the same problem. The study showed that there was an association between a high BMI and wheeze in boys and young men of borderline statistical significance, but otherwise, the associations were weaker and not significant.
With females are more likely to develop asthma after puberty, the researchers think that part of the explanation for this may be the increase in body fat in females after
The Otago researchers studied a group of 1,037 children, just over half of which are male, who were born between
April 1971 and March 1973. These children have been participating since birth in the University of Otago’s Dunedin
Multidisciplinary Health and Development Study. At age 26, 980 or 96 percent of the 1,019 living study members were still