Systemic inflammation and its response to treatment in patients with asthma

Abstract

Background: Asthma is an obstructive airway disease characterized by airway inflammation.

Objective: To measure systemic inflammation in asthma patients, and to assess the effect of treatment on systemic inflammation.

Methods: In 30 newly diagnosed non-randomized adult asthma patients we measured systemic inflammation markers (serum high-sensitivity C-reactive protein, total leukocyte count, and erythrocyte sedimentation rate) before and after a 6-week standard treatment with inhaled steroids and inhaled β(2) agonist. The comparison group comprised 20 healthy control subjects. All the subjects were non-smokers.

Results: The measured systemic inflammation markers were higher in the asthma patients: high-sensitivity C-reactive protein 4.8 ± 6.0 mg/dL vs 1.5 ± 1.4 mg/dL, P < .001; total leukocyte count 8,936 ± 2,592 cells/μL versus 7,741 ± 1,924 cells/μL, P < .001; erythrocyte sedimentation rate 24.8 ± 12.3 mm/h versus 15.3 ± 6.5 mm/h, P < .001. In the asthma patients, high-sensitivity C-reactive protein negatively correlated with percent-of-predicted FEV(1) (r = -0.64, P = .001), percent-of-predicted forced vital capacity (FVC) (r = -0.39, P = .03), FEV(1)/FVC% (r = -0.71, P < .001), and percent-of-predicted forced expiratory flow during the middle half of the FVC maneuver (FEF(25-75)) (r = -0.51, P = .004). Total leukocyte count negatively correlated with percent-of-predicted FEV(1) (r = -0.64, P = .001), percent-of-predicted FEV(1)/FVC (r = -0.74, P < .001), and percent-of-predicted FEF(25-75) (r = -0.58, P = .001). Body mass index positively correlated with high-sensitivity C-reactive protein (r = 0.65, P < .001). Multiple linear regression showed significant correlation of high-sensitivity C-reactive protein (r(2) = 0.75) with age (β = 0.31, P = .008), body mass index (β = 0.99, P = .001), family size (β = 0.33, P = .008), and weight (β = -0.45, P = .01). The systemic inflammation markers decreased significantly (P < .001 for all comparisons) after 6 weeks of treatment: high-sensitivity C-reactive protein decreased from 4.8 ± 6.0 mg/dL to 2.4 ± 5.4 mg/dL, total leukocyte count decreased from 8,936 ± 2,592 cells/μL to 6,960 ± 1,785 cells/μL, and erythrocyte sedimentation rate decreased from 24.8 ± 12.3 mm/h to 15.8 ± 10.1 mm/h.

Conclusions: Inhaled steroids plus inhaled β(2) agonist significantly reduced systemic inflammation in asthma patients.