title: White matter damage and systemic inflammation in obstructive sleep apnea.
abstract: OBJECTIVE
  To evaluate white matter integrity in patients with obstructive sleep apnea (OSA) using diffusion tensor imaging (DTI) and to assess its relationship with systemic inflammation.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  One tertiary medical center research institute.
  
  
  METHODS
  Twenty patients with severe OSA (apnea-hypopnea index [AHI] > 30, 18 men and 2 women) and 14 healthy volunteers (AHI < 5, 11 men and 3 women).
  
  
  METHODS
  N/A.
  
  
  RESULTS
  Patients with severe OSA and healthy volunteers underwent polysomnography to determine the severity of sleep apnea, and DTI scanning to determine fiber integrity. Early or late phase changes in leukocyte apoptosis and its subsets were determined by flow cytometry. DTI-related indices (including fractional anisotropy [FA], axial diffusivity [AD], radial diffusivity [RD], and mean diffusivity [MD]) were derived from DTI. The FA maps were compared using voxel-based statistics to determine differences between the severe OSA and control groups. The differences in DTI indices, clinical severity, and leukocyte apoptosis were correlated after adjusting for age, sex, body mass index, and systolic blood pressure. Exploratory group-wise comparison between the two groups revealed that patients with OSA exhibited low FA accomplished by high RD in several brain locations, without any differences in AD and MD. The FA values were negatively correlated with clinical disease severity and leukocyte early apoptosis.
  
  
  CONCLUSIONS
  Obstructive sleep apnea impairs white matter integrity in vulnerable regions, and this impairment is associated with increased disease severity. The possible interactions between systemic inflammation and central nervous system microstructural damage may represent variant hypoxic patterns and their consequent processes in OSA.
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.|Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Hsiu-Ling
authors.initials: HL
authors.lastname: Chen
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.|Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Cheng-Hsien
authors.initials: CH
authors.lastname: Lu
authors.affiliation: Department of Otolaryngology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.|Sleep Center, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Hsin-Ching
authors.initials: HC
authors.lastname: Lin
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Pei-Chin
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Brain Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kun-Hsien
authors.initials: KH
authors.lastname: Chou
authors.affiliation: Department of Diagnostic Radiology, Chiayi Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Chiayi, Taiwan.
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Lin
authors.affiliation: Department of Neurology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Nai-Wen
authors.initials: NW
authors.lastname: Tsai
authors.affiliation: Department of Biological Science, National Sun Yat-Sen University, Kaohsiung, Taiwan.|Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Yu-Jih
authors.initials: YJ
authors.lastname: Su
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Division of Sleep Surgery, Rush University Medical Center, Chicago, IL.|Department of Otolaryngology, Advanced Center for Specialty Care, Advocate Illinois Masonic Medical Center, Chicago, IL.
authors.forename: Michael
authors.initials: M
authors.lastname: Friedman
authors.affiliation: Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan.|Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ching-Po
authors.initials: CP
authors.lastname: Lin
authors.affiliation: Department of Diagnostic Radiology, Kaohsiung Chang Gung Memorial Hospital, and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Wei-Che
authors.initials: WC
authors.lastname: Lin
mesh_terms: D000328:Adult; D016880:Anisotropy; D017209:Apoptosis; D015815:Cell Adhesion Molecules / Q000378:metabolism; D003430:Cross-Sectional Studies; D056324:Diffusion Tensor Imaging; D066026:Endothelial Progenitor Cells / Q000166:cytology; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000473:pathology; D007249:Inflammation / Q000150:complications*; D007962:Leukocytes / Q000473:pathology; D008297:Male; D017286:Polysomnography; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology; D066127:White Matter / Q000473:pathology*
chemical_list: D015815:Cell Adhesion Molecules
keywords: diffusion tensor imaging; leukocyte apoptosis; magnetic resonance imaging; obstructive sleep apnea; oxidative stress