The Influence Of Lung Volume Changes On Sleep Apnea

Objective To investigate the influence of obstructive sleep apnea(OSA)to lung function and the role of lung volume in the termination mechanisms of OSA.Methods We analyzed 71 consecutive patients with snore and all patients had in-hospital overnight polysomnography and daytime pulmonary function testing which include ventilation index: forced Vital capacity (FVC), forced expiratory volume in 1 s (FEV1), maximal voluntary ventilation (MVV), peak expiratory flow (PEF), and the indicators of lung volume:residual volume(RV),functional residual volume (FRV), expiratory reserve volume (ERV), total lung capacity (TLC), Vital capacity (VC), inspiratory capacity (IC). Based on the assessment of the apnea-hypopnea index (AHI), these patients were divided into four groups: primary snoring group (AHI<5/h, n=11), and the mild (AHI 5-20/h, n=15), moderate (AHI>20-40/h, n=17) & severe (AHI>40/h, n=28) OSAHS groups.Results T T-test demonstrated no difference in age and the pulmonary function parameters between the four groups except MVV,IC. Correlation analysis indicated that AHI,AI,ODI,TSaO290%,LSaO2 was not correlated with MVV,TLC,RV,FRV,VC,IC (p>0.05),but FRV was positively correlated with LAD(r=0.296, p<0.05),TLC,RV,FRV was positively correlated with MAD(r=0.345,0.425,0.465, p<0.01)a few of lung function parameters was correlated with Age and BMI, after control them , partial correlation manifest that TLC,RV,FRV was still positively correlated with MAD and LAD, (r=0.440～0.318, p<0.01或p<0.05).Conclusion After control Age and BMI,AHI will not influence ventilation function and lung volume in OSAHS patients,MAD and LAD was positively correlated with TLC,RV,FRV indicate lung volume may play a role in the termination pathophysiology of OSA.