Being obese or underweight ups risk of asthma in adolescents

London: Your body mass index (BMI) may determine the risk of asthma in childhood. While overweight adolescent girls may be at a higher risk of hospital admission due to asthma, boys who are underweight are likely to be at risk of being admitted with the lungs disease, a study said.

Asthma is a lung condition in which a person's airways become inflamed, narrow and swell and produce extra mucus.

The study showed that risk of hospital admission due to asthma was significantly higher for overweight than for normal and underweight girls, with the strongest link seen with the BMI measurements taken at the age of 13.

Overweight women had a 39 per cent increased relative risk of asthma admission. 

Conversely, boys who were underweight in childhood had a higher risk of asthma admission in early adulthood compared to those with normal BMI, with the strongest link seen with the BMI measurements taken at the age of 12.

Underweight boys had a 24 per cent increased risk of being admitted with asthma.

"The study presents an intriguing look at the differences we see between men and women when we identify predictors of asthma among children. This could be due to a range of factors including levels of physical activity, lung mechanics and different environmental factors," said lead author Charlotte Suppli Ulrik, Professor at the University of Copenhagen in Denmark.

"We hope that our findings can aid clinicians identifying asthma risks in different individuals. By understanding which individuals are at risk of developing more severe asthma, we can encourage lifestyle changes that can help reduce this risk," Ulrik suggested.

For the study, the team analysed information on BMI measurements taken annually (age 7-13 years) in over 300,000 school children to hospital admissions for asthma in early adulthood. 

The findings were presented at the 2016 European Respiratory Society's International Congress in London, recently.