Relationships of haptoglobin level to FEV1, wheezing, bronchial hyper‐responsiveness and allergy

Abstract
The relationships of haptoglobin level to respiratory and allergic parameters have been assessed in an epidemiological study conducted in a working population surveyed twice 5 years apart. At the first survey conducted in 892 working men, haptoglobin level was significantly related to FEV1 (r = -0.18; P less than 0.001) and smoking habits. After adjustment for smoking, a history of wheezing was significantly related to lower haptoglobin level. A second survey conducted in 304 men of the original sample 5 years later confirmed that haptoglobin was related to FEV1 (r = -0.21; P less than 0.001) and that wheezing was significantly related to hypohaptoglobinaemia (lower decile; P = 0.04). Men who exhibited bronchial hyper-responsiveness to methacholine had haptoglobin levels 0.35 g/l higher than those who did not (P = 0.01). Haptoglobin level was unrelated to IgE level and skin prick tests. These results support the hypothesis of the role of inflammation in both lower lung function and bronchial hyper-responsiveness. They suggest that some heterogeneity exists within subjects with a history of wheezing.