Plasma phospholipase A2 activity in patients with asthma: association with body mass index and cholesterol concentration.

Background: Secretory phospholipases A 2 (sPLA 2 ) 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 sPLA 2 activity in patients with stable and acute asthma and to assess potential associations with body mass index (BMI), and plasma cholesterol and vitamin C concentrations. Methods: Plasma sPLA 2 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, sPLA 2 activity was measured in 36 patients experiencing acute asthma and in 22 of these patients after recovery from the acute attack. Results: sPLA 2 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 2 activity, while plasma vitamin C was inversely correlated with sPLA 2 activity in patients with stable asthma and in control subjects. There were significant interactions between gender and plasma cholesterol and between gender and vitamin C in relation to sPLA 2 activity. Conclusions: Plasma sPLA 2 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.