Preliminary Study On Clinical Subtypes Of Obstructive Sleep Apnea Hypopnea Syndrome

Objective:The clinical presentations of obstructive sleep apnea hypopnea syndrome(OSAHS) appear to be heterogenous.OSAHS severity is usually classified using the apnoea-hypopnoea index(AHI),which may not reflect the heterogeneity of distinct clinical manifestations of OSAHS. In this study,we investigate the clinical subtypes of OSAHS using multiple clinical variables.Methods:A total of 308 patients examined by a full-night polysomnography were retrospectively analyzed in the respiratory department of the Second Affiliated Hospital of Nanchang University between 2012 February and 2015 May, 255 men and 53 women with OSAHS aged 20~85 years(average 49.38±13.38 years) were analysed.First,PCA was performed using ten variables selected for their relevance to OSAHS:age,body mass index(BMI),AHI, lowest oxygen saturation(LSa O2%),longest apnea time(LAT),arousal index,Epworth sleepiness scale(ESS), comorbidities,cumulative smoking and symptoms.Then,cluster analysis techniques based on PCA was used to identify subtypes of OSAHS.Results:1.Five main components were identified by PCA,which accounted for 73.091%of variance, components 1: AHI ? BMI ? ESS ? LSa O2, components 2:age ?comorbidities, components 3:ESS ? symptoms, components 4:LAT ? cumulative smoking, components 5: arousal index.2.Four distinct clinical subtypes were identified. Subtype 1: middle aged(55.82±12.55age)patients with higher BMI(25.76±3.14 kg/m2), shortest duration time of sleep apnea( 65.17±31.60 s VS98.28±19.37 s VS83.13±25.43 s VS111.23±41.15s), had higher prevalence of comorbidities(1.50±1.06VS1.01±0.98VS0.67±0.70VS1.00±0.30);Subtype 2 : middle aged(45.76±11.37age)patients and obesity(28.22±3.85kg/m2),Sa O2% was the lowest(63.80±10.91%VS79.44±6.93 %VS67.70±11.43%VS77.71±10.55%),had a higher arousal index(80.29±39.06VS45.10±24.70 VS 34.01±18.54VS49.68±24.92);Subtype 3 : younger(41.86±11.00age)patients and obesity(29.17±3.68kg/m2), lower arousal index(34.01±18.54 VS 45.10±24.70 VS 80.29±39.06 VS 49.68±24.92), ESS score was the highest(8.43±4.51 VS 5.94±3.03 VS 6.97±4.13 VS 5.84±3.83); Subtype 4 : old(61.13±10.39age) patients with higher BMI(25.32±3.52kg/m2), the duration time of sleep apnea was the longest(111.23 ± 41.15 s VS 65.17 ± 31.60 s VS 98.28±19.37 s VS83.13±25.43s), high smoking index( 929.68±461.62VS97.99±196.13 VS135.83±201.14VS221.29±310.58), minimally symptomatic patients(6.10±2.00 VS 7.34±2.79VS7.77±2.13VS8.18±2.40). There were statistical significances among all groups(p<0.05).Conclusion:1.This study confirms the heterogeneity of OSAHS and combines AHI and other characteristics can better reflect the heterogeneity of OSAHS.2.Four distinct clinical subtypes were identified,Subtype 1 :middle aged patients with higher BMI, shortest duration time of sleep apnea,had higher prevalence of comorbidities;Subtype 2:middle aged patients and obesity,Sa O2% was the lowest,had a higher arousal index;Subtype 3:younger patients and obesity, lower arousal index,ESS score was the highest; Subtype 4:old patients with higher BMI, the duration time of sleep apnea was the longest,high smoking index,minimally symptomatic patients.