Scientists have discovered a link between obesity and asthma, a finding which may help to explain why overweight people are up to twice as likely to develop the condition.
Researchers at the Centre in Allergic Mechanisms of Asthma at King's College London extracted cells called Th2 cells - which cause the inflammation that triggers asthma - from the blood of obese patients.
They found that, as well as causing asthma, the cells secrete high levels of the hormone promelanin, which plays a crucial role in controlling appetite.
Lead researcher Dr David Cousins, an immunologist at King's College London, commented: "Our study provides evidence for a possible mechanism linking obesity and asthma."
However, he noted that not all people with asthma are obese and revealed that the team will be looking at the gene responsible for the promelanin hormone to discover the role of variations.
Jenny Versnel, executive director of research and policy at Asthma UK, said that obese people often find it harder to manage their asthma symptoms.
"This research is important because it could potentially help some people with asthma to gain more effective control of their condition," she added.