WASHINGTON -?Children with asthma may be at higher obesity risk later in childhood or in adolescence, according to new research published online this week.

Researchers from the University of Southern California found that young children with asthma were 51 percent more likely to become obese over the next 10 years than children who did not have asthma.

However, the good news is that the use of asthma rescue medications reduced the risk of becoming obese by 43 percent.

"Asthma and obesity often occur together in children, but it is unclear whether children with asthma are at higher risk for onset of obesity or whether obese children develop asthma, or both," said Zhanghua Chen, lead author and a postdoctoral research associate of preventive medicine at the University of Southern California.

"Our findings add to the literature that early-life asthma history may lead to increased risk of childhood obesity," Chen said.

Chen and her colleagues looked at 2,171 kindergarteners and first graders who were not obese at the time they were enrolled for the study.

At enrollment, 13.5 percent of the children had asthma.

During a follow-up of up to 10 years, 15.8 percent of all these children developed obesity.

Researchers confirmed study results in a different group of children, who were recruited in the fourth grade and followed until high school graduation.

They found several risk factors for obesity are more prevalent among children with asthma, including reduced physical activity and potential adverse effects from asthma medications.

The results also showed that the use of rescue asthma medications appeared to reduce the risk of developing obesity.

The researchers called the fact that rescue, but not controller, asthma medications reduced obesity "a surprise" and said it warranted further study.

Overall, the study reinforced the importance of early diagnosis and treatment of asthma, which "may avoid the vicious cycle of asthma increasing the development of obesity with obesity subsequently causing increased asthma symptoms and morbidity leading to further weight gain," they wrote.

The findings were published in the American Journal of Respiratory and Critical Care Medicine.