Relationship Of Obstructive Sleep Apnea Hypopnea Syndrome With Metabolic Syndrome And Nonalcoholic Fatty Liver Disease

Background: Obstructive sleep apnea(OSA) is severely associated with visceral adiposity(VA). OSA was a serious sleep disordered breathing(SDB) affecting metabolic syndrome(Met S). VA could potentially contribute to the incidence of Met S.Rencently, a novel and simple indicator of VA and metabolism--visceral adiposity index(VAI) has attracted more attention in the field of metabolic disfunction. Unfortunately,little is known regarding the relation between VAI, OSA and Met S. On the other hand,as one of the prime liver manifestation of metabolic dysfunction, nonalcoholic fatty liver disease(NAFLD) is highly associated with OSA. To our knowledge, except for some experiments focusing on liver injury in lean mice after chronic intermittent hypoxia(CIH), considerable attention has been given to the influence of OSA on liver injury in obese or morbid obese patients. As far as we are aware, few investigations involving nonobese adults have been done regarding the association of OSA with NAFLD to date. Our purpose was to explore the correlation of VAI with Met S, NAFLD and liver enzymes, and to analyze the significance in VAI and the application to discriminate risks of both Met S and NAFLD among OSA patients. Additionally, the correlation between OSA and NAFLD in nonobese petients were also investigated.Methods: Participants with repetitive snoring or clinical complaint of SDB referred to SDB clinic center of Fujian province, between January 2014 and December 2015. All individuals underwent collection of history of diseases, medicine, and examination of height, weight, blood presure, and testing of polysomnography(PSG) and biochemical parameters including triglycerides, fasting glucose and liver enzymes. Additionlly, an abdominal ultrasonography scan during this period was taken for 304 patients among them. The differences in PSG parameters, liver enzymes, high sensitive C-reactive protein(hs-CRP) and VAI based on apnea-hypopnea index(AHI) were investigated(AHI<5/h and 5-15/h, 15–30/h, >30/h). Correlation between VAI, OSA indices and liver enzymes was evaluated using spearman’ rank analysis. It would be acquired using the receiver operating characteristic(ROC) curve to get cut-offs of VAI predicting Met S and NAFLD. The independent risk of developing NAFLD was also obtained by logistic regression in the setting of nonobese OSA patients.Results: 1. Totally, 361 of 411 participants were diagnosed as OSA with 67 patients in mild group, 89 moderate and 205 severe.(1) The indices of serum glucose,triglycerides(TG), incident Met S, VAI and metabolic score differed significantly(all p<0.05).(2) Close relations of VAI with mean nocturnal oxygen saturation, AHI and metabolic score were found(all p<0.05).(3) Based on the cut-offs of 2.282, 2.105,2.511(for all subjects, males and females, separately), OSA patients were predisposed to suffer from Met S(odds ratio [OR]=10.237, p=0.001; OR=13.556, p=0.001;OR=21.458, p=0.000). 2. Additionally, the number of participants who underwent abdominal ultrasonography examination was 304(220 males and 84 females). Their mean age were 51.1+11.3 years. According to severity of OSA, the amounts of related group were 40, 62, 78, 124.(1) Sex, age, liver function markers among groups did not differed significantly.(2)By contrast, demography parameter as waist circumference,PSG markers as AHI, lowest oxygen saturation(La SO2), oxygen desaturation index(ODI) differed significantly. Similaly, VAI, gamma glutamyl transferase(GGT),aspartate aminotransferase(AST), alanine aminotransferase(ALT) and incident NAFLD were different(3) VAI was positively linked with AHI(β=0.222, P=0.007), ODI(β=0.216, P=0.006), ALT(β=0.237, P=0.004) and GGT(β=0.238, P=0.003).(4) The cut-off value of VAI 1.59 could indicate NAFLD for all individuals through ROC curve.It was disposed for SDB patients to develop NAFLD when VAI>1.59(OR=4.550, P<0.001). 3. Furthermore, among 304 participants undergoing abdominal ultrasonography scan, a total of 175 participants were included the period 3 according to obesity criterion.106 NAFLD subjects were seperated into four groups.(1) Differences in TG, ALT and AST, hs-CRP did not existed with the aggravation of OSA.(2) Body mass index(BMI),La SO2, and TG differed in those OSA patients with or without NAFLD.(3)Further,NAFLD could be independently promoted by BMI, La SO2, and TG(OR = 1.563, p =0.002; OR = 0.960, p = 0.030; OR = 3.411, p = 0.000, seperately).Conclusions: As a simple approach acquired in everyday practice, VAI was closely related with OSA, Met S and NAFLD. It would remind OSA patients of the risk of Met S and NAFLD. In nonobesity, significant differences in liver enzymes may not be affected by OSA. OSA patients should realize the hazard of lipid, obesity and hyoxemia in elevating the risk of NAFLD. It was warranted to conduct more large-scale and prospective researches in the impact of OSA on Met S and NAFLD.