Changes in ventilation function and sleep structure in patients with obstructive sleep apnea/hypopnea syndrome accompanied by cardiovascular disease

Objective To study the changes in ventilation function and sleep structure in patients with obstructive sleep apnea/hypopnea syndrome(OSAHS) accompanied by cardiovascular disease and assess the efficacy of nasal continuous positive airway pressure(nCPAP).Method The sleep structure,hypopnea index(HI),apnea index(AI),apnea-hypopnea index(AHI),and minimum oxygen saturation(MinSaO_2) were analyzed in OSAHS patients with and without cardiovascular disease,and snoring patients with and without cardiovascular disease as controls.Twenty-eight OSAHS patients with cardiovascular disease were monitored before and after nCPAP therapy.Result AI in OSAHS with cardiovascular disease group were significantly higher than those in OSAHS alone group(P0.05).The time periods of awakening and stage 3,4 sleep in OSAHS with cardiovascular disease group were significantly shorter than those in OSAHS alone group(P(0.01),P0.05).The nCPAP therapy among mild to severe OSAHS patients with cardiovascular disease led to improvement in polysomnographic indices: AHI significantly decreased(P0.05) while MinSaO_2 increased(P0.05).The time periods of stage 3,4 sleep in severe group were significantly prolonged(P0.05) whereas the time period of stage 2 was significantly shortened(P0.01).Conclusions The ventilation function and sleep structure are significantly disordered in OSAHS patients with cardiovascular disease.The nCPAP therapy efficiently improves the morbid condition in such patients.