For years, doctors have known that there is a link between childhood
obesity1 and
asthma2, but have found it difficult to determine which condition tends to come first, or whether one causes the other. An article published in the September issue of Annals of
Allergy3, Asthma and Immunology, the scientific publication of the American College of Allergy, Asthma and Immunology (ACAAI), suggests it is more probable that childhood obesity contributes to asthma, although the connection is complex and has many factors.
"The relationship between obesity and asthma in adults, which shows that being overweight and
obese4 can precede the
onset5 of asthma, is supported by a number of studies," said allergist Perdita Permaul, MD, lead author. "There isn't as much evidence for children, but the progression from obesity to asthma, rather than the other way around, seems probable." The article cites a study that showed that rapid growth in body mass index (BMI) during the first 2 years of life increased the risk of asthma up to 6 years of age. It has also been shown that the onset and duration of obesity and the composition of the excess fat -- lean vs. fat -- can affect lung function.
In a proverbial chicken vs. egg
scenario6, doctors often don't know if the
constricting7 of
airways8 caused by asthma causes kids to not want to exercise, and therefore to gain unhealthy amounts of weight, or if it is because kids are overweight that their airways narrow and they develop asthma.
"Most kids who suffer from asthma also have allergies," said allergist Michael Foggs, MD, ACAAI president. "These
allergic9 responses in the lung can lead to symptoms of allergy. Coughing,
wheezing10 and shortness of breath are all symptoms that make exercise harder. We work with our asthma patients to make sure they are breathing well enough to exercise and play."
According to ACAAI, children with asthma and other allergic diseases should be able to participate in any sport they choose, provided the allergist's advice is followed. Asthma symptoms during and immediately following exercise may indicate poorly controlled asthma.