In general, the higher the BMI, the greater the ozone response, providing one more reason why maintaining a healthy body weight is important to your health. When subjects were put into categories of body fatness defined by the US Centers for Disease Control based on their BMI, the ozone-related drops in lung function, particularly the forced expiratory volume in one second (FEV1), were lowest in underweight people (BMI less than 18.5), greater in normal weight people (BMI 18.5 to 25) and greatest in overweight individuals (BMI above 25). BMI is a measure of fatness based on an individual's height and weight.
Its notable that these results came out of a study that was done in a population of predominantly normal weight individuals, said London. This suggests that these effects may be even more important in the general population where there are large proportions of overweight and obese individuals. An estimated two-thirds of U.S. adults are overweight or obese, with a BMI greater than 25, according to CDC[i].
The physiologic mechanisms responsible for the decline in lung function after ozone exposure with increasing BMI are not clear, although the authors suggest that perhaps circulatory hormones and other inflammatory factors may play a role. These factors have been shown to affect airway hyper-responsiveness and inflammation in animal models.
The authors note too that the study was limited in the small number of obese individuals (the subjects had not been selected with a study of BMI in mind) and by having only one measure of a persons body fat. Future studies of the effects o
'/>"/>
| Contact: Robin Mackar rmackar@niehs.nih.gov 919-541-0073 NIH/National Institute of Environmental Health Sciences Source:Eurekalert |