Objective To study the clinical features of obstructive sleep apnea hypopnea syndrome(OSAHS) in the elderly by comparison with the young or middle-aged OSAHS patients.Methods Randomly selected 161 OSAHS patients were divided into elderly group(n=72) and young or middle-aged control group(n=89).The clinical data and polysomnographic parameters were compared between the two groups.The therapy options for the patients,followed by phone calls,were also compared between the two groups.Results The apnea hypopnea index(AHI),the lowest oxygen saturation,and oxygen desaturation index(ODI) were significantly lower in elderly group than in body mass index-matched young or middle-aged controls(P<0.05).The systolic blood pressure was higher,but the diastolic blood pressure and heart rate were lower in elderly group than in young or middle-aged controls(P<0.05).In elderly OSAHS patients,blood pressure was positively associated with AHI,ODI,and arousal index.The acceptance of surgery and oral appliances in elderly OSAHS patients was significantly lower than that in young or middle-aged controls(P<0.01),but the acceptance of continuous positive airway pressure was not significantly different between the two groups(P>0.05).Conclusion The elderly patients suffer less severe OSAHS than young or middle-aged patients.AHI,ODI,and arousal index may be related to the increased blood pressure of elderly OSAHS.The elderly OSAHS patients have lower acceptance of surgery and oral appliances compared with young and middle-aged controls.