A study of 4,500 men and women in the US has uncovered a new link between obesity and asthma.
Writing in the medical journal Allergy, Dr Jun Ma of the Palo Alto Medical Research Institute in California found that the risk of developing asthma more than tripled for the most obese individuals compared with people whose weight was considered to be normal.
The study examined data from the National Health and Nutrition Examination Survey for 2005-2006. The sample group was split into three different weight categories: those who were overweight, those who were considered to be at a normal weight and those who were classed as obese.
The study revealed that 12% of the obese individuals had asthma, compared with just 6% of those in the normal weight category.
The risk of developing the allergy also increased threefold for those in the obese weight group after the team uncovered a link between the likelihood of developing asthma and a rising BMI.
Although the reasons for the relationship are still largely unknown, some believe the system-wide, low grade inflammation that is witnessed in obese individuals could contribute.
Others believe a resistance to insulin could also be a key factor after the study revealed that 37% of the obese group were either diabetic or insulin resistant. Although no evidence was found to link the two, Dr Ma said it could still be a factor.