A Norwegian study has revealed that belly fat is linked to the development of asthma.
Previous studies have found a link between asthma and body mass index (BMI), which is a marker for overall obesity but the new study undertaken looked at the circumference of the waist, which is a marker for central obesity, to see whether this form of obesity could also contribute to the risk of asthma.
The researchers followed 23,245 adults without asthma, aged 19-55 years from the second Norwegian Nord-Trondelag Health Study (HUNT), for 11 years.
The participants had their BMI measured along with their waist circumference to test overall obesity and central obesity, and were also asked to report incidence of asthma.
The results showed that people who were centrally obese but not overall obese were 1.44-times more likely to develop asthma and that people who were both centrally obese and obese overall were 1.81-times more likely to develop asthma.
"Asthma can affect people of all sizes, but our study has highlighted both the individual and combined effect of central obesity and overall obesity on asthma development. Both these measures have an individual impact on asthma and an additive effect when they are combined," Ben Brumpton from the Norwegian University of Science and Technology, said.
"It is not yet clear why this association exists. Central obesity is closely associated with insulin resistance and metabolic syndrome. These factors may play important roles concerning central obesity-related asthma. We will evaluate the effects of these factors on the development of asthma in future studies," he added.