Daytime sleepiness and driving ability in obstructive sleep apnea-hypopnea syndrome drivers

Objective To evaluate the relationship between excessive daytime sleepiness and nocturnal hypoxemia and apnea-hypopnea index(AHI).Methods Polysomnography was carried out in thirty-two patients with obstructive sleep apnea-hypopnea syndrome(OSAHS)and ten controls.The Epworth Sleepiness Scale(ESS)and driving ability were also evaluated in these subjects.In order to assess the relationship between sleepiness and nocturnal hypoxemia and severity of OSAHS,the patients were divided into three groups according to AHI,and multiple stepwise regression was used.Results (1)Patients with OSAHS had low driving ability and higher ESS Scale than controls(ESS Scale 15.34±4.80 and 7.60±4.65 respectively,P0.05).ESS was correlated with AHI(r=0.782,P0.001)and nadir nocturnal oxygen saturation(MmSpO2)(r=-0.744,P0.001).(2)Multiple stepwise regression showed that:ESS was correlated with AHI and nadir nocturnal oxygen saturation(MmSpO2).The equation was as follows:Y(ESS)= 19.441-0.132X1(MmSpO2)+0.109X2(AHI)(R2=0.651,P0.05).Conclusion (1)Patients with OSAHS have more severe daytime sleepiness and significantly decreased driving ability,which means high risk to car accidents,especially in patients with AHI≥40.(2)ESS is closely correlated with AHI and nadir nocturnal oxygen saturation(MmSpO2)in OSAHS patients.