Children with asthma seem more likely to become obese than those without asthma, the American Journal of Respiratory and Critical Care Medicine reported recently. However, rescue medications seem to reduce the risk.
The researchers enrolled 2,171 non-obese children. At baseline, the mean age was 6.6 years, 18.3 per cent were overweight and 13.5 per cent had diagnosed asthma. During the median 6.9 years follow-up, 15.8 per cent became obese.
Children with asthma at baseline were 51 per cent more likely to become obese compared to controls. The authors replicated the findings in 2,684 children between the mean ages of 9.7 and 17.8 years: those with asthma at baseline were 56 per cent more likely to develop obesity than controls.
Children with history of wheeze at baseline were 42 per cent more likely to develop obesity than children who never experienced wheeze. The risk of obesity was 46 per cent higher for asthma that began up to and including four years of age and 39 per cent higher for onset older than four years. Using asthma rescue medications at the start of the study reduced the risk of obesity by 43 per cent, independently of physical activity and use of other asthma medications.
The biological mechanisms that underlie the increased risk of obesity in people with asthma are “uncertain” but long-term glucocorticosteroids can increase lipid uptake from the diet and promote storage in tissues, particularly in the trunk. The authors speculate that beta-agonists might “have direct effects on adipocytes and lipolysis and protect against obesity”.
Frank Gilliland, senior study author and Hastings professor of preventive medicine at the University of Southern California, said the fact that beta-agonists, but not steroids, reduced obesity was a surprise and warranted further study.
The overall study findings reinforce the importance of early diagnosis and treatment of asthma, he said, which might counter “the vicious cycle of asthma increasing the development of obesity and obesity causing increased asthma symptoms.”