Effect Of Age On The PSG Of Patients With Obstructive Sleep Apea Syndrome

Objective:The aim of this study was to elucidate the PSG characteristics of the young patients compared to the elderly or middle-aged patients with OSAHS.Method:A total of 263 patients who were found to have OSAHS between 2007-2009 were enrolled .The patients were divided into 3 groups: young (age between 18-44),middle-aged (age between 45-59),elderly (age≥60).According to result of polysomnography and anthropometric indicators, we compared the apnea hypopnea index (AHI),body mass index(BMI) , mean oxygen saturation (MSaO2) ,lowest oxygen saturation (LSaO2) and neck circumference between patients of different ages. Spearman's correlation coefficients were calculated to determine the relationships between AHI and obesity-related variables:BMI and neckcircumference. According to different AHI ,patients were divided into two groups: those with moderate-to-severe apnea (5≤AHI≤20) and those with mild apnea (AHI>20). Pearson correlation and receiver operating characteristic (ROC) curves for BMI and neck circumference were made to evaluate independent variables for utility in predicting OSAHS.Result :The age structure was different between male and female (p<0.05) .In male , the young and middle-aged patients were more ;but in female ,middle-aged and elderly patients played an imporyant part .The neck circumference of elderly was smaller than the young and middle-aged patients in men (p<0.05). The neck circumference of middle-aged was significantly larger than the middle-aged and the elderly group(p<0.05). Overall, The neck circumference of the elderly group was the smallest(p<0.05). The BMI of the young and middle-aged patients was significantly higher than the elderly(p<0.05). The BMI of the middle-aged group was significantly higher than the elderly in women(p<0.05). The BMI of the male patients was higher than the female's in the same age group(p<0.05). The percentage of overweight and obesity(p<0.05) in the elderly group is the lowest(p<0.05). The AHI was higher in the young and middle-aged patients than the elderly, MSaO2,LSaO2 were lower than the the elderly(p<0.05). The longest apnea duration and MAI were higher than the younger(p<0.05). There were significant correlations between obesity-related anthropometric variables such as BMI, neck circumference and AHI in all age groups(p<0.05).According to the prediction of middle-to-severe apnea(AHI>20),the respective area under the ROC curve of neck circumference and BMI was 0.877,0.74,the difference was considered significant(p<0.05), neck circumference of 41.4cm was the best predictor.Conclusion : The age structure was different between male and female. OSAHS is more severe in the young and middle-aged patients than the elderly, the Condition deteriorated in postmenopausal in women. There were significant correlation between BMI, neck circumference and AHI. Overweight or obesity was also an important factors affecting severity of the OSAHS patients.The high collapsibility of the upper airways may be another reason of the high prevalence of the elderly beside obesity.Compared with BMI, neck circumference may be a better predictor of middle-to-severe OSAHS.