Background: Secretory phospholipases A2 (sPLA2) have functions relevant to asthmatic inflammation, including eicosanoid synthesis and effects on dendritic cells and T cells. The aim of this study was to measure sPLA2 activity in stable and acute asthmatic patients and to assess potential associations with body mass index (BMI) and plasma cholesterol and vitamin C concentrations.
Methods: Plasma sPLA2 activity and concentrations of cholesterol and vitamin C were measured in 23 control subjects and 61 subjects with stable asthma (42 mild to moderate, 19 severe). In addition, sPLA2 activity was measured in 36 patients experiencing acute asthma and in 22 of these patients after recovery from the acute attack.
Results: sPLA2 activity was not significantly greater in severe (499.9 U, 95% confidence interval (CI) 439.4 to 560.4) compared with mild to moderate asthmatic subjects (464.8, 95% CI 425.3 to 504.3) or control subjects (445.7, 95% CI 392.1 to 499.4), although it was higher in patients with acute asthma (581.6, 95% CI 541.2 to 622.0, p<0.001). Male gender, high plasma cholesterol, increased BMI and atopy were associated with increased sPLA2 activity, while plasma vitamin C was inversely correlated with sPLA2 activity in the stable asthmatic and control subjects. There were significant interactions between gender and plasma cholesterol and between gender and vitamin C in relation to sPLA2 activity.
Conclusions: Plasma sPLA2 may provide a biological link between asthma, inflammation, increased BMI, lipid metabolism and antioxidants. Interactions among these factors may be pertinent to the pathophysiology and increasing prevalence of both asthma and obesity.
- acute asthma
- asthma severity
- body mass index
- phospholipase A2