Abstract
Asthma is a chronic inflammatory disease related to oxidative stress. Previously, we reported that superoxide dismutase activity (SOD) is lower in asthma as compared to healthy controls and related to airflow obstruction and reactivity. In this study, we hypothesized that serum SOD would be informative for progression of asthma over time. To test this, asthmatic adults (n=47) [age:40+3, mean%FEV1:77+5, FEV1/FVC: 0.69+0.1, gender: M/F=17/30, severe asthma n=12] were evaluated longitudinally over 4 years. SOD levels at the start of the study were significantly lower in Asthmatics as compared to Control subjects (p<0.001). Asthmatic adults had greater than the normale ∼25 ml/year decline in vital capacity; severe asthmatic adults tended to lose more than nonsevere asthmatics [decline FVC ml/year: nonsevere, 51+16; Severe, 120+30; p=0.04). Asthmatics were classified as high or low SOD depending on whether their serum SOD was above or below the median (15 U/ml). Asthmatics classified as high SOD had the most accelerated FVC loss [decline FVC ml/year: Low SOD, 42+13, High SOD, 108+27;p=0.05). The decline in FVC/year was related to SOD activity at enrollment (R= -0.624, p=0.006). These results suggest that asthmatics with high SOD experience a progressive loss of SOD activity over time and are at risk for accelerated loss of lung functions.
- © 2011 ERS