No abstract

No abstract

No abstract

No abstract

Introduction: The incidence of asthma has increased dramatically over the last several decades, in tandem with a rise in obesity. Studies suggest that IL-6 may play a key role in disease pathogenesis in obesity-associated asthma. We sought to examine the relationship between IL-6 levels and lung function in asthmatics, and the impact of obesity and metabolic dysfunction. Methods: We utilized the Coronary Artery Risk Development in Young Adults (CARDIA) cohort to confirm associations between IL-6, asthma and metabolic dysfunction. In this cohort, a history of asthma, metabolic disease, lung function measurements, CRP and serum IL-6 were collected. We performed a cross sectional analysis of the cohort at year 20, as this was the timepoint for IL6 measurements. In addition, we compared median IL6 in the black vs the white population overall irrespective of asthma status. Univariable and multivariable stepwise regression analyses of (log)IL6 were performed on demographic and clinical variables (see table). Metabolic syndrome, as defined by NIH criteria was included in the model. The 95th percentile of IL6 was used as the cutoff to determine high (vs low) IL6. Wilcoxon rank sum test was used to compare clinical data between groups. Results: Our analysis included 858 healthy (without co-morbid diseases or asthma) and 448 individuals with asthma. Our cohort included a large number of healthy subjects and a high proportion of blacks. While the univariable analyses showed all the variables were significantly associated with (log)IL6, only race (Black), CRP, FEV1, BMI and metabolic dysfunction were significant in the multivariable model as shown in the table below. The black population had higher IL6 levels (median=1.64, p<.0001) than whites (median=1.18). The individuals who met criteria for metabolic syndrome also had higher (log)IL6 levels (median=0.90 vs median=0.43, p<.0001). We found a positive association of (log)IL6 with CRP (r=0.51, p<.0001) & BMI (r=0.41, p<.0001). Increasing (log)IL6 negatively correlated with FEV1(r=-0.25, p<.0001). IL6 appears to be an independent factor affecting lung function with lean asthmatics with high IL6 levels demonstrating a significant reduction in the FEV1 (median=2.35, IQR=2.06-2.69; p=0.003) compared to those with low IL6 levels (median=2.88, IQR=2.41-3.37). Obese subjects with asthma and high IL6 demonstrate the most significant reduction in lung function. Conclusion: High IL6 asthma is associated with the greatest reduction in lung function and a greater likelihood of metabolic dysfunction. The black population had higher mean IL6 levels indicating that a race specific reference range may be appropriate.