Relationship Between Obstructive Sleep Apnea-hypopnea Syndrome And Nonalcoholic Fatty Liver Disease By Fibroscan

Background:Obstructive sleep apnea-hypopnea syndrome?OSAHS?and nonalcoholic fatty liver disease?NAFLD?are both common diseases.In recent years,the incidence of disease has been increasing with the prevalence of obesity,both of which have become the focus of people's health attention.Past studies had shown that there was a close relationship between OSAHS and NAFLD.Liver biopsy?LB?examination is still the gold standard for diagnosis and classification of NAFLD so far.However,due to the disadvantages of large traumatic,pain,complications,poor repetitiveness and stability,it is not routinely recommended in clinical.At present,the new noninvasive and rapid examination---Liver Transient elastography?Fibroscan?,which yields high specificity,sensitivity,repetitiveness and stability has been gradually recognized in the filed of diagnosis of nonalcoholic fatty liver disease.The purpose of this study is to identify NAFLD populations in OSAHS early through a simple and noninvasive technique?Fibroscan?,to further explore the correlation between OSAHS and NAFLD,and to evaluate the differences of liver enzyme,liver stiffness and fat attenuation reference value between different degrees of OSAHS groups.Additionally,the differences of OSAHS related indexes between non-fatty liver group and fatty liver group are also discussed.The major contributing factors for elevated liver stiffness and fat attenuation reference value is investigated.Methods:It was a retrospective study.All participants had repetitive snoring or clinical complaint of SDB.67of them which had the testing of polysomnography?PSG?and liver transient elastography?Fibroscan?referred to SDB clinic center of Fujian province between February 2015 to July 2017.All individuals underwent collection of age,sex,the history of diseases,medicine,and examination of height,weight,neck circumference,waist circumference,the Epworth sleepiness score?ESS score?and other parameters,Fasting venous blood including blood lipid,liver enzyme,fasting blood glucose and other hematological indexes were collected.The differences in PSG related parameters,liver stiffness,fat attenuation reference value,fasting blood-glucose and liver enzyme on apnea-hypopnea index?AHI?were investigated?AHI?15/h and>15-30/h,>30/h?.In addition,We also investigated the differences between PSG related parameters,liver stiffness,fat attenuation reference value,fasting blood-glucose and liver enzyme based on fat attenuation reference value?CAP=240dB/m?.Correlation between liver stiffness,fat attenuation reference value and PSG related parameters,fasting blood-glucose,liver enzyme were evaluated using spearman'rank analysis.Multiple linear regression analysis was used to explore risk factors for NAFLD in OSAHS.Results:?1?A total of 67 subjects with 58 males and 9 females were included(mean age 45.31±11.26 years,mean body mass index?BMI?28.93±3.94kg/m².?2?ESS score,apnea-hypopnea index?AHI?,oxygen desaturation index?ODI?,the percentage of sleep duration with SpO₂<90%?TS90%?and fat attenuation reference value significantly increased with the aggravation of OSAHS,while meanSpO₂,LaSO₂ significantly decreased?all p<0.05?.?3?Based on the cut-offs of the CAP value of 240 dB/m?15non-fatty liver,52 fatty liver?,there were 12 OSAHS?AHI?5?in the non-fatty liver group and 51 OSAHS in the fatty liver group.The prevalence of OSAHS in fatty liver group was significantly higher than that in non-fatty liver group.Neck circumference,waist circumference,ESS score,BMI,AHI,ODI,TS90%,liver stiffness,fat attenuation reference value,ALT significantly increased with the aggravation of CAP value,while meanSpO₂,LaSO₂ significantly decreased?all p<0.05?.?4?Close relations of liver stiffness with sex,neck circumference,waist circumference,BMI,TS90%,ALT,aspartate aminotransferase?AST?were found?all p<0.05?,so as the fat attenuation reference value with neck circumference,waist circumference,BMI,AHI,TS90%,ODI,ALT,AST,mean SpO2,LaSO2?all p<0.05?.?5?In multivariate analysis,Sex,ODI,AHI was the major contributing factor for elevated In liver stiffness??=0.037,p=0.003.?=0.006,p=0.04.?=-0.006,p=0.016?.AHI was the major independent predictor of elevated fat attenuation reference value??=0.754,p=0.023?.Conclusions:In conclusion,AHI is independently correlated with liver stiffness and fat attenuation reference value after eliminating confounding factors.Our study has suggested that AHI might be a potentially useful clinical marker to identify patients at risk of NAFLD.Fibroscan is a noninvasive,rapid,reproducible and stable method for measuring liver stiffness.Therefore,Fibroscan may help us screen NAFLD in OSAHS earlier.