Women with waists bigger than 88 cm are more likely to have asthma even if they are not overweight, it has been revealed.
US scientists have discovered that abdominal fat is linked to developing the condition, which currently affects over five million people in Britain.
A research team from Northern California Cancer Centre in Berkeley studied results from a California Teachers Study, which started in 1995.
The study of 88,304 female teachers and school administrators took part in the research, with 11,500 registered as being obese with a body mass index (BMI) of more than 30.
Overweight women were judged to have a 40% higher risk of developing adult-onset asthma and those who were obese were more than twice as likely to end up having the condition. Women who were not clinically overweight but had a waistline of 88cm or more also had an increased chance of developing asthma.
The researchers said: "This study confirms the association between excess weight and asthma severity and prevalence, and showed that a large waist was associated with increased asthma prevalence even among women considered to have normal body weight."
The research has been published in the journal Thorax.