Asthma Prevalence Switches Gender By Puberty

While boys are more likely to outgrow asthma and its symptoms with age, girls find it difficult to get rid of the problem as the years pass, specially after the onset of puberty, making it a more permanent condition in them; says latest study report.

The research, funded by the National Institutes of Health, has its report published in the American Journal of Respiratory and Critical Care Medicine.

Where on one end the study found more boys to be susceptible to Asthma in childhood as compared to girls, it also found the former to grow out of the condition more easily, showing very few instances of the attack after puberty sets in, which was not the case in girls.

The study was conducted by a team at Harvard Medical School and the Brigham and Women's Hospital in Boston.

In a first ever attempt to understand the disease from gender differences point of view, the researchers conducted study on 1041 asthmatic children, testing them annually for over nine years.

Ranging between the age group of 5-12 years, the children were administered with airway constriction testing drugs, which induced asthma like symptoms.

While methacholine was given as a challenge to test Airway Responsiveness (AR), annual spirometric testing was also received by each child, analyzing the same.

Over the years researchers found that age made boys less prone to the development of asthma like symptoms after given methacholine, while girls showed little improvement.

The research conducted in five stages divided as per the ages of the children as they grew, showed that age 11 was the last age where the responsiveness to methacholine challenge was similar in girls and boys.

At age 8 and 10 years, that is, the stage 1 and 2, the differences in responsiveness were minimum. However, after about 8.6 years, boys had become more tolerant to increased doses of the drug also. This indicated a decrease in the disease severity.

But it was found that the AR results of boys and girls began diverging at stage 3, which is around 12 years of age, the age that coincides with puberty. At this stage where 2.7mg/ml of methacholine provoked an airway constriction in boys, the measurement was lesser in girls at 2.0mg/ml.

The trend progressed through the rest of the stages with the difference widening as the age of the participants increased.

At stage 4, when the participants were 16 years of age, 3.1mg/ml of the drug was required to provoke constriction in boys, while in girls 1.8mg/ml brought the reaction.

At stage 5 (18 years), while 27 percent of boys showed no significant change in the AR results, only 14 percent of girls managed to do so. Rest of them showed no improvement in the condition.

While researchers were not able to specifically identify the role of puberty hormonesdefine like estrogen and progesterone, in this kind of reaction, they consider puberty to be a major influencing factor.

Dr. Tantisira, lead author of the study, considers the research to be a big help in managing asthma in adolescent patients.

"One of the things we have a hard time with is, knowing when to stop medications," he said. He also said that the research would atleast help doctors to now figure out the differences in dosage adjustments in girls and boys. While girls would have to continue with their medication abandoning it in a more “gradual approach”, boys with fewer or no attacks of asthma could get lucky and halt the maintenance medication completely.