Inverse Association between Pulmonary Function and C-Reactive Protein in Apparently Healthy Subjects

Rationale: Increased levels of systemic markers of inflammation have been reported in patients with impaired lung function due to obstructive or restrictive lung disease.Objective: We tested the hypothesis that a decline in lung function within the normal range may be associated with a systemic subclinical inflammation.Methods: Pulmonary function tests, cardiorespiratory fitness, components of the metabolic syndrome, and high-sensitivity C-reactive protein (CRP) were determined in 1,131 subjects without known pulmonary disease.Measurements and Main Results: Ninety-six of the study participants (8.5%) had FEV1 of less than 80% of predicted values. There was a strong inverse association between CRP levels and quartiles of FEV1. The median CRP levels in nonsmoking participants were 2.5, 1.8, 1.7, and 1.3 mg/L in the first, second, third, and forth FEV1 quartiles, respectively (p < 0.0001). A similar inverse association was present in smoking subjects (median CRP levels were 3.8, 2.3, 2.0, and 1.9 mg/L in the...