title: Abnormal mitochondria organization and oxidative activity in the palate muscles of long-term snorers with obstructive sleep apnea.
abstract: BACKGROUND
  Histopathological alterations and a reduced number of capillaries have been observed in the palate muscles of snorers with obstructive sleep apnea syndrome (OSAS). These changes may create a substrate for decreased microcirculation, impaired aerobic metabolism and muscle dysfunction and contribute to upper airway obstruction during sleep.
  
  
  OBJECTIVE
  The aim was to analyze mitochondria distribution and oxidative enzyme activity in relation to capillary supply in the palate muscles of patients with a history of long-term snoring and OSAS.
  
  
  METHODS
  Palatopharyngeus (PP) and uvula (UV) muscle samples were obtained from 8 patients undergoing uvulopalatopharyngoplasty due to habitual snoring and OSAS. The muscles were analyzed with enzyme- and immunohistochemistry and morphometry.
  
  
  RESULTS
  Abnormalities in the internal organization of mitochondria and oxidative activity were observed in 39 ± 15% of the fibers in the PP and 4 ± 3% in the UV, but not in control samples. The majority of these fibers had a lobulated contour and trabecular internal organization of mitochondria. The number of capillaries around abnormal fibers (PP 0.9 ± 0.3, UV 0.4 ± 0.1) was lower than in fibers of a normal appearance in both patients (PP 1.4 ± 0.6, UV 1.2 ± 0.3) and references (PP 2.7 ± 0.7, UV 1.9 ± 0.9) (p < 0.05).
  
  
  CONCLUSIONS
  Abnormal mitochondrial distribution, a low capillary supply and signs of impaired oxidative activity suggest that muscle dysfunction of the palate muscles in long-term snorers may contribute to the upper airway obstruction during sleep. The cause of these abnormalities remains unclear, but local muscle and nerve trauma due to vibration and stretch is a possible etiology.
authors.affiliation: Department of Integrative Medical Biology, Section for Anatomy, Umeå University, Umeå, Sweden. per.stal@anatomy.umu.se
authors.forename: Per S
authors.initials: PS
authors.lastname: Stål
authors.forename: Bengt
authors.initials: B
authors.lastname: Johansson
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D001706:Biopsy; D002196:Capillaries / Q000473:pathology; D016022:Case-Control Studies; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D005355:Fibrosis; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000473:pathology*; D018485:Muscle Fibers, Skeletal / Q000378:metabolism; D009210:Myofibrils / Q000378:metabolism; D009246:NADH Tetrazolium Reductase / Q000378:metabolism; D013517:Otorhinolaryngologic Surgical Procedures; D010156:Palatal Muscles / Q000098:blood supply / Q000201:enzymology* / Q000473:pathology*; D010160:Palate, Soft / Q000601:surgery; D010614:Pharynx / Q000601:surgery; D020181:Sleep Apnea, Obstructive / Q000601:surgery*; D012913:Snoring / Q000601:surgery*; D013385:Succinate Dehydrogenase / Q000378:metabolism; D014609:Uvula / Q000601:surgery
chemical_list: D013385:Succinate Dehydrogenase; D009246:NADH Tetrazolium Reductase; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases