Associations between Fluorescent Oxidation Products (FlOPs) level and change in asthma outcomes

Abstract

High FlOPs level, a global oxidative stress biomarker, was associated cross-sectionally with poor asthma outcomes but its longitudinal association with asthma evolution has never been examined. We studied the associations between FlOPs level and changes in asthma activity, control and attacks over 8 years. Longitudinal analyses were conducted in 489 adults with ever asthma from the Epidemiological Study on the Genetics and Environment of Asthma (baseline 2003-07; follow-up 2011-13). Associations between plasma FlOPs level at baseline and changes in asthma activity (based on asthma treatments and attacks in the past 12 months), control (GINA 2015) and attacks were evaluated by logistic regressions adjusted for age, sex and smoking. For each asthma outcome, we compared the persistent group (+/+) to the remittent one (+/-, reference) and the relapse group (-/+) to the stable one (-/-, reference). At baseline, mean age was 39 years; 51% were men, 71% had active asthma, 38% had asthma attacks and 41% had poor asthma control. FlOPs Geometric Mean (Q1-Q3) was 91.5 (78.5-102) RFU/mL. Among participants with controlled asthma at baseline, those with high FlOPs level had a higher risk of poor asthma control at follow-up (adjusted OR for one interquartile range increase in FlOPs, 95% CI: 1.63, 1.16-2.28). High FlOPs level was also associated with a higher risk of persistent asthma activity (1.32, 0.89-1.97) although the latter association was not statistically significant. No other association was observed. Results showed that higher FlOPs level was associated with loss in asthma control and suggest FlOPs as a predictor of asthma evolution in adults and a good candidate marker in asthma management.