| Objective: 1) to assess the potential relationship between parameters of airway resistance measured by impulse oscillometry and serum concentrations of surfactant proteins(SPs) in OSA patients; 2) to further investigate possible involvement of airway resistance in OSA pathogenesis.Methods: This is a complementary cross-sectional study. 46 subjects who performed overnight polysomnography, plethysmograph, impulse oscillometry and measurement of serum SPs were enrolled. Subjects with apnea hypopnea index ≥10events/h were defined as OSA group.Parameters of lung volume(FVC, FEV1, TLC) and airway resistance properties(Zrs5, R5-35,X5-35) were measured by plethysmograph and impulse oscillometry respectively and SP-A, B, C and D by ELISA.Results: OSA was diagnosed in 22 patients(47.8 %). Mean age and BMI was 45.6±6.73 years and28.3±3.22kg/m2 respectively. 1) non-smoking OSA subjects displayed significantly lower serum SP-A(133.37±29.43 vs 162.54±24.96ng/L, p=0.021), SP-B(40.78±4.28 vs 48.89±6.37ng/L,p=0.002) and SP-D(15.68±2.73 vs 19.32±3.51ng/L, p=0.016), and significantly larger R5-R20(0.08±0.04 vs 0.05±0.03 k Pa/L/s, p=0.035) than did non-OSA subjects; 2) significant negative correlation was observed between SP-D and respiratory system resistance at 5-20Hzs(r=-0.438,p=0.041) in non-smoking subjects, which was even stronger among subjects with BMI≥28kg/m2.Conclusion: OSA patients showed decreased serum SP-A, B and D and increased airway resistance. Serum SPs, particularly SP-D, were associated with increased airway resistance and might be involved in the pathogenesis of OSA in non-smoking patients.Smoke and obesity might be influence factor to the production and secretion of SPs. |
